Cereals provide much of the energy in poultry feeds, corn in the US and parts of Canada, wheat in Western Canada, parts of Europe, and Australia. The cost of feed energy (apparent Metabolizable Energy, AME) is the single greatest cost of poultry production, and the amount of energy in a cereal is essential knowledge for adequate poultry nutrition.
Feed mills use a process called “least-cost formulation” to calculate which ingredients to use in a mixed feed and in what proportions. This ensures that the requirements of the specific type of bird are met at the minimum cost. To use least-cost formulation, nutritionists need values for the requirements of the bird, the cost of the available ingredients, and their nutrient contents. Despite changes in production due to genetic selection, nutrient requirements are fairly well understood. Ingredient costs can change rapidly, but their calculation is direct. A weak link in the chain of least-cost formulation is the determination of the nutrient content of some ingredients, particularly in the energy content of cereals other than corn.
The US National Research Council (NRC, 1994) provides the nutrient contents of many feed ingredients, including wheat, and these values are commonly used for feed formulation. NRC provides two energy values for wheat: 2,900 kcal/kg for hard red winter wheat (3,330 kcal/kg on a dry matter basis), and 3,120 kcal/kg (3,510 kcal/kg on a dry matter basis) for soft white winter wheat. What happens if these values are wrong? If the values are too low, feed will be over-formulated and the extra energy will increase the cost of the feed. If they are too high, feed will be under-formulated and performance may be compromised. Either way, the producer has less control of the feeding program.
There has been a feeling in Western Canada that the values provided by NRC for the energy in wheat are too low. It is known that both the genotype (cultivar) and the environment in which the wheat is grown affect the AME value. The AME of wheat was investigated by Dr. Tom Scott at the Pacific Agri-Food Research Center (PARC) in Agassiz, in collaboration with H. L. Classen, M. L. Swift, and M. R. Bedford in a study funded by The Alberta Barley Commission, The Canadian Wheat Board, Finnfeeds International, IRAP/NSERC, The BC Broiler Chicken Marketing Board, and Agriculture and Agri-Food Canada.
Using a bioassay for broilers that was developed at PARC, Dr. Scott measured the energy derived from 108 samples of wheat of nine different varieties grown in three locations in Western Canada over a two-year period. This bioassay measures not only the AME of the sample, but also the viscosity of the intestinal contents of birds fed the cereal (measured as centipoise), and their performance. The intestinal viscosity is measured to determine the anti-nutritive effects of soluble non-starch polysaccharides (NSP), which wheat contains. High levels of NSP produce a viscous solution in the gut that interferes with digestion, especially in young birds, and produces sticky droppings. Enzymes can be added to the feed to counteract these effects, and because this practice has become widespread, it was done for one-half of each of the samples.
As expected, both the year and the specific growing environment affected the feeding value of the samples. The growing environment is difficult to control, and knowing that there are differences simply points out that routine tests may be necessary. Knowing the effect of the cultivar is more useful. Table 1 shows the nine cultivars of wheat tested along with the class of wheat to which they belong. Durum wheat is primarily used in the production of pasta, Canadian Prairie Spring (CPS) cultivars (Glenlea is actually considered a feed wheat) are used extensively in animal feed, and Hard Red Spring (HRS) wheat is traditionally valued the most because of the high protein content.
Table 1 (below) also shows that both the digesta viscosity of the broilers and the AME obtained were dramatically different for these nine wheat cultivars. With no enzyme supplementation, digesta viscosity was lowest for the Durum wheat varieties and highest for the HRS varieties. Enzyme supplementation dramatically reduced the intestinal viscosity and the anti-nutritive properties of the NSP. It also removed much of the difference between the cultivars. Along with the differences in intestinal viscosity, there were marked differences in the AME extracted by the birds and without enzyme, there was about a 10% difference between the highest and lowest values. The AME values for the Durum varieties were well above those given by NRC. With enzyme supplementation, all nine cultivars had AME contents that were higher than either value provided by NRC. Even with enzyme supplementation, Durum cultivars still contained more than 100 kcal/kg more energy than other cultivars.
Table 1. The digesta viscosity and AME for nine cultivars of wheat in diets with and without enzyme supplementation.
Digesta Viscosity (centipoise) AME (kcal/kg)
|Cultivar1||No Enzyme||Enzyme||No Enzyme||Enzyme|
|CDC Teal (HRS)||18.8c||3.8bc||3460bc||3620bc|
a-e Means within followed by no common letter are significantly different at P < 0.05.
1CPS is Canadian prairie spring wheat, DUR is durum wheat, and HRS is hard red spring wheat.
How does this relate to broiler performance? Table 2 (below) confirms what was seen above in Table 1. There were significant differences between cultivars, with the Durum wheat cultivars producing the heaviest broilers at 17 days, and doing it most efficiently. Enzyme supplementation significantly improved performance and it reduced the difference between cultivars.
Table 2. Performance of chicks fed nine cultivars of wheat in diets with and without enzyme supplementation.
17-day Body weight (g) Feed:Gain Ratio (g:g)
|Cultivar1||No Enzyme||Enzyme||No Enzyme||Enzyme|
|CDC Teal (HRS)||346de||370c||1.61bc||1.53ab|
a-f Means within followed by no common letter are significantly different at P < 0.05.
1CPS is Canadian prairie spring wheat, DUR is durum wheat, and HRS is hard red spring wheat.
These data reflect several problems with current feed formulation when wheat is the major energy source. The wheat cultivars differed considerably. Durum wheat is likely undervalued for growing broilers, the CPS cultivars had lower energy values than other types, and the HRS cultivars produced the highest intestinal viscosity. When wheat-based diets are supplemented with enzymes to reduce the effects of NSP, the AME values reported by NRC are too low. This could result in over-formulation and increased feed costs.
It seems clear from these data that when using least-cost formulation of broiler diets, feed mills should consider the cultivar of wheat being used and whether it will be supplemented with enzyme.
National Research Council, 1994. Nutrient Requirements of Poultry. 9th ed.
National Academy Press, Washington, DC. Scott, T. A., F. G. Silversides, H. L. Classen, M. L. Swift and M. R. Bedford, 1998.
Effect of cultivar and environment on the feeding value of Western Canadian wheat and barley samples with and without enzyme supplementation. Can. J. Anim. Sci., in press.
Dr. F. G. Silversides is a scientific writer living on Denman Island, British Columbia, Canada.
Dedicated to finding practical solutions that producers can use to fight common infectious diseases that still plague food-producing animals, the Veterinary Infectious Disease Organization (VIDO) was formed to bridge between basic science and its application on the farm.
VIDO's objective is the control of common infectious diseases through preventative measures, drugs and management techniques that producers can readily use on their farms. High on the list of disorders to tackle are scours, mastitis, pneumonias, shipping fever and coccidiosis.
Founded in 1975, after a thorough investigation through the Science Council of Canada, VIDO is located on the University of Saskatchewan campus. This allows scientists access to the support facilities of the Western College of Veterinary Medicine and other agricultural and medical research units. Financially, VIDO is independent of the University of Saskatchewan.
A new $4.25 million laboratory and a unique isolation building will be functioning early next year. These are already paid for through grants received from four major donors: Devonian Group of Charitable Foundations, University of Saskatchewan, and Alberta and Saskatchewan provincial governments.
The first major project of VIDO is the study of scours in calves and pigs for the next 3 to 5 years, according to the director, Dr. Chris Bigland.
"Scours cost Canada's beef and dairy industry over $74 million in 1974. That's $8.67 for each calf born alive and that's why we started with scours," said Bigland. "Results of the disease can be devastating to both hog and cattle producers."
VIDO researchers are already making progress in their investigation of scours by using both actual farm conditions and sophisticated laboratory equipment.
Dr. Steve Acres, a research associate is experimenting with management control techniques and also field testing a new vaccine. He is preparing a detailed report of his findings for release early in 1978.
Dr. Bob Worthington, a visiting scientist from South Africa has had encouraging results from his experiments to produce a toxin vaccine to control the many strains of E. coli bacteria that cause diarrhea in animals.
Dr. Bigland emphasized the importance of producer input to VIDO's research plans. "We're sensitive to producer needs and we'll respond to them. It doesn't matter if it's the poultry, cattle, swine or sheep industry that has a problem. We want to tackle the common diseases that other organizations seem to be ignoring."
"VIDO has charted a 10 year research plan and the next major disease we'll study is the pneumonia complex, if our agricultural economist pinpoints it as the most costly disease after scours," he said.
Seven and a Half Million For Next 5 Years
To carry on this unique type of practical research, Bigland stressed the need for long term funding. "Our goal is to raise $7.5 million for the next 5 years of operation," he said.
He explained that VIDO hoped to raise $2.5 million from the Canadian government, $2.5 million from contract research grants, livestock association check-offs and private donations.
"VIDO is a national livestock research facility and the work we do will benefit all Canadians," he said. "That's the reason we're asking for support from all levels of government."
"If the livestock associations give us their backing, we can get some of our funding from governments," he pointed out. "But first governments want to see moral and financial support from the producers."
Dr. Bigland suggested that livestock producers could obtain more detailed information about VIDO by contacting him at the VIDO trailers in care of the University of Saskatchewan in Saskatoon.
"VIDO represents a practical, down-to-earth way t beat the common infectious diseases that have cost our livestock producers so much money for so many years," he concluded.
What do we want to find in "tomorrow's egg"? Let us examine the egg part by part and set some goals for the future; and then let's see if we have any hope of accomplishing those goals.
First there is the shape of the egg to consider. Tomorrow's egg does not need to have a different shape than today's egg but it would certainly help a lot to have al of tomorrow's eggs uniformly shaped alike.
Uniform egg shape would make it possible to tailor our crates, case and cartons to do a better job of protecting the eggs from breaking. That would be the biggest economic reason for wanting uniform egg shape in tomorrow's egg. I also think the consumer would find packages of eggs with uniform shape more attractive and maybe buy a few more.
Something else to consider is the mechanization of the poultry and egg industry. More and more operations of handling eggs are being done mechanically. Any designer of egg handling equipment will tell you that his machine will work better for "normally" shaped eggs than for others. The producer can do himself and the handler of eggs a considerable service by making tomorrow's eggs uniform in shape.
What sort of shell would we like to have on tomorrow's eggs? What about shell colour? We all know that colour of the shell has nothing to do with the quality inside, so I think that we shouldn't worry too much about shell colour. I would like to see tomorrow's uniform colour in each carton. I believe we can merchandise eggs of one colour almost as easily as eggs of another colour.
Uniformity of shell colour, and shape, too, as mentioned before, make a more attractive pack. These are two of the things that can make it easier to sell the product. In my opinion the egg packer has more responsibility in doing something about shell colour than the producer. Producers should remember, though, that the fewer colours of shell that the packer gets, the easier his job will be.
Need Stronger Shells
The main things we expect the shell to do are to carry the contents of the eggs until we're ready to use them and to protect the contents from evaporation and contamination. Tomorrow's egg ought to have a strong shell whether it is laid in April or August and it should be more resistant to evaporation. We're very lucky that eggs have shells on them. Many foods aren't that well protected by nature.
In shell eggs today we pin most of our quality ratings on the albumen, the thick albumen to be more specific. We do that because we think that an egg with lots of thick "up-standing" white is what the consumer wants. If we're right, and I think we are, then tomorrow's egg ought to have more and thicker albumen that will keep its high quality longer.
What about yolk colour? The consumer surveys that have been made in the last few years indicate that consumers in general don't prefer any one yolk colour over another. They may draw the line at extremely dark or extremely light yolks, but that leaves a pretty big range of colour that doesn't seem to worry them too much. Here again, I'm going to fall back on that word "uniformity."
We want uniformity in almost everything, particularly food. If the last hot dog you ate tasted especially good you'd like the next one to taste just like it. If your last suit wore like iron, you want your next one to do that, too. I believe the consumer would be happy with almost any yolk colour within reasonable limits if all yolks were about the same colour.
Next time you have two eggs sunny side up for breakfast, take a look at the yolks. If one is darker than the other, I'll bet you expect one of them to taste better. You may think you'll like the dark one or you may think you'll like the light one. It doesn't matter which – the important thing is that if there is a lack of uniformity, you will usually think that one is going to be better than the other. We could prevent this sort of consumer confusion by giving them uniform yolk colour.
The yolk of tomorrow's egg won't have any defects on it such as mottling or other areas that appear abnormal. There won't be any blood and meat spots in tomorrow's egg either. I don't need to dwell on these points. We wish today's eggs didn't have these defects but they do sometimes so we will make if out goal to completely eliminate them from tomorrow's eggs.
One more thing that tomorrow's egg can have that will make it even more desirable, and that is increased nutritive value. The egg is almost without peer in nutritive value now. If it can be improved in nutritive value so much the better.
The Practical Approach
These are some pretty lofty goals. Let's be practical – what are the possibilities that we can reach those goals? I think we can reach all of them. Some will take longer than others, but none of them are impossible.
Take shell colour, for example. We have been working with instruments in U.S.D.A. laboratories that could be developed into machines for automatically segregating eggs by the colour of their shells. When the egg industry feels that it will be profitable for them to pack eggs for uniformity of shell color, I have no doubt that it can be done mechanically.
I also mentioned uniformity of egg shape. It has been demonstrated many times that egg shape is inherited. When we decide what egg shape we want, poultry breeders can produce birds that will lay that shape.
Yolk colour is predominately influenced by feed, and controlling the amount of pigment in the feed controls yolk colour. But that may not be the whole story. There is some research going on at Beltsville indicating that yolk colour may be partly controlled by inheritance. This work hasn't been going on very long yet, but it is beginning to look as though we might have some breeding as well as feeding control over yolk colour.
It has been known for 20 years or so that egg shell quality is influenced by heredity. We also know that feeding the proper balance and amount of minerals is important in getting good shells. What are the possibilities of getting eggs with superior shell strength and low evaporation rate?
Several years ago the U.S.D.A. researchers reported on breeding for egg shell quality by using the weight loss of the egg in the incubator. They found that it was possible to develop a good shell quality line and a poor shell quality line, showing that the ability produce good shell is inherited. They also found that the shells of the eggs with the low weight loss were the strongest. This work indicates that it is possible through breeding, accompanied by proper feeding, to put a shell around tomorrow's eggs that is stronger and allows less evaporation.
Can Reach Goal
Can we reach our goals of albumen quality? We want a high percentage of thick white that stands up well when first laid and deteriorates slowly. It has been shown that, through breeding, birds can be developed that will lay eggs which deteriorate more slowly than ordinary. This work is not yet completed but it points the way to one more of the things we want in tomorrow's egg.
On the subject of blood and meat spots and mottled yolks there isn't anything new to report. You've been told many times that though breeding they can be eliminated almost entirely. I think elimination of blood and meat spots ought to be the first of our goals for tomorrow's egg that we try to reach – and the sooner the better.
The vitamin content of the yolk of an egg is influenced by the feed of the bird. Tomorrow's egg can be made nutritious by feeding for higher vitamin content.
Where are we right now in all of this? What is the quality of today's egg? The truth of the matter is we don't know. A lot has been learned about where quality losses occur during marketing and a lot has been learned about preserving egg quality by processing and by cold storage. A lot has also been learned about breeding for egg quality. We need to know more about all of these. But the one thing we haven't looked at in any detail at all yet is the quality of eggs as they are laid.
Last spring and summer a program got under way to do something about it. Associated Poultry and Egg Industries has adopted the program. It is call the I.Q. (Interior Quality) Programme. The first thing to be done is to find out the level of quality being produced. To do that, observations on the interior quality of newly laid eggs are going to be taken in some of the egg laying contests. That will go a long way toward telling us what sort of egg quality today's laying stock produces.
When we get the needed information about today's egg we will know better how far we have to go to produce tomorrow's egg. Let me summarize very briefly. Tomorrow's egg should have:
- Uniform shape,
- Uniform shell colour in any one carton,
- Greater shell strength,
- Less evaporation from the egg,
- A high percentage of thick white,
- A thick white that stands up high and deteriorates slowly,
- Uniform yolk colour,
- Freedom from blood and meat spots and mottled yolks, and
- Higher nutritive value.
These goals can all be reached. They will be reached, of course, only when such eggs are more profitable to those who produce them. Obviously then, no one segment of the poultry industry can be asked to carry the ball alone. Improved egg quality at the production level must be accompanied by improved marketing and handling of eggs. At the same time, improved merchandising will have to provide the economic encouragement needed to keep an egg quality improvement programme on the move.
Fashions don't necessarily change every year with chickens, that is, with the feathered kind. However, they are now changing rapidly in modern poultry raising.
Whereas standard type and colour have obsessed the fancier and exhibition breeder of the past, quantity egg and meat production are the dominant objectives of the commercial poultryman in 1951. While the first quarter of the century was marked by remarkable gains in egg production, the second quarter, recently concluded, has witnessed the consolidation of these gains in breeding flocks and the dissemination of better blood lines throughout the flocks of the world.
The magnitude of these gains in total production may be appreciated when it is realized that, as the statisticians tell us, the average hen lays 50 more eggs now than she did 50 years ago. Multiply this increase by the number of hens (500,000,000) on this continent, and we can only try to imagine he astonishing increase of 24 billion eggs that are available for human consumption in one year. In Canada alone, this increase amounts to about 2 billion eggs per annum, worth $60,000,000. To take care of this, the annual per capita consumption of eggs has increased from around 200 to 390 eggs in the United States – more than an egg a day – the highest in the world, and 300 eggs in Canada.
It is remarkable that, while such progress was being made in the production and consumption of eggs, the production and marketing of poultry meats had just dragged along as incidental to egg production. Poultry meats, in other words, have been largely represented by surplus birds not kept for egg production, and in many cases, have been poor meat type and quality. Within the past few years, it has been realized that not only the production but the marketing of poultry meats have been grossly neglected. In one branch alone, viz., broiler production, a startling change has taken place, one that promises to revolutionize chicken-meat production if it has not already done so. No longer is the light, skinny, bony broiler of 7 to 9 weeks fashionable.
Instead, great numbers of thick-meated and tender "baby beef" chickens are being produced, weighing 3 to 4 lb. or better at 12 weeks – 50 per cent more than the old-fashioned chicken. These frying chickens are being turned out by mass production methods in one to ten thousand lots or more, in big roomy pens, where they may be crowded but remain healthy as they are nourished by modern efficient rations. Such birds, moreover, grow so quickly into delicious tender meat that chicken-meat now competes in both quality and price with all other meats to be found on the market.
These modern chickens have to be early and full feathering, uniformly rapid growing, vigorous, plump-breasted, with maximum edible meat and minimum waste, to meet market requirements. In other words, they must be "prime" when very young. If the birds are kept to the heavier roaster or capon stage, they must be capable, moreover, of maintaining heavy weights desired. To make good roasters, they must also be completely feathered and comparatively free of pin-feathers when prime.
It was indicated some years ago, in the annual reports of poultry meat inspection of the Dominion Markets Branch, that the better grades were decidedly in the minority, and that there was urgent need for a breeding and selection program that would include not only the maintenance of egg production but extra pressure of selection for improved meat type in the breeding stock of this country.
Breeding research at the University of B.C.
There are two schools of thought as to the methods of breeding better meat types of chicken. One is to use out-crosses of the extremely broad-breasted low-set Cornish – an extreme type of meat game produced by fanciers – to such well-known utility breeds as the New Hampshire, Rhode Island Red, or Plymouth Rock, and to breed back to the latter breeds until a type is more or less fixed. Some remarkably fine meat strains have evolved from these and other crosses in the past three years, as they have proved in the famous "Chicken of Tomorrow" contests that have brought so much publicity to the broiler business in the United States. In order to provide certification for R.O.P. in meat production, the U.S. Department of Agriculture is inspecting random sample progeny tests from matings entered by private breeders this year.
Another approach to the problem of improving meat type in poultry is through certification of meat characteristics as well as egg production in flocks already entered in R.O.P. This would merely involve further extension of existing inspection in Canadian R.O.P. to cover such economic factors as rate of growth in addition to early feathering and meat type as included at present.
Selection for market qualities
Under R.O.P. regulations, selection for improved meat type and better feathering has been continuous in University of British Columbia flocks of Barred Rocks and Rhode Island Reds since 1935. No significant correlation was found to exist between meat type and egg production in these strains, thus simplifying the dual purpose objective in breeding and selection. Little was known in the earlier stages about the mode of inheritance of various feathering characteristics in these two breeds, except that slow feathering appeared to be dominant to early fast feathering. The inheritance of full feathering was not fully understood although the Leghorns possessed the quality.
At first selection consisted largely of discarding the slowest feathering types and the sharper breasted, angular meat specimens, and including only the better feathering, plumper breasted birds in the breeding pens. Arbitrary classifications were used to distinguish various grades. Observations were made of feathering, and weights taken at ages of 6 weeks in chicks and at regular intervals until maturity. Families were marked according to grading of offspring and undesirable ones eliminated. The U.B.C. strain of Reds is now pure for early fast feathering, but lacks the full feathering of the White Leghorn or certain strains of New Hampshires. Recent studies indicate that a bareback factor and slow feathering in the neck, hackle, and tail may be factors inhibiting full feathering in birds pure for the early feathering gene.
The popularity of the Barred Plymouth Rock as a table bird had until recent years become almost proverbial on general farms in Canada. While its position has recently been challenged by the New Hampshire and to a lesser degree by the White Rock and Light Sussex, the Barred Rock has earned its prestige in the trade for its feeding and fattening qualities and ability to finish well as a roasting chicken or a heavy, fat fowl. In these forms its fleshing is unsurpassed. The Barred Rock, however, has not been so suitable for broiler or fryer production because of some slow-feathering characteristics and lack of uniformity in many strains.
In order to utilize the desirable qualities of both the Barred Rock and Red, including the autosexing colour pattern of the former, a crossing project was undertaken to fix the white barring factor in the early fast-feathering Reds. By first crossing a Barred Rock male to Red females and back crossing to Red, and then to Barred Reds in succeeding generations, pure Barred Reds (autosexing Redbars) were produced. They were superior in meat type, and tested 96.3 per cent accurate in autosexing. Meanwhile the U.B.C. strain of New Hampshires was giving good performance in eggs and meat production and hatchability. Moreover, although a newer breed, they excelled in viability, showing the greatest resistance to disease, including the paralysis complex. Lacking only the barring characteristics for autosexing purposes, a Barred New Hampshire (Hampbar) bred after the fashion of the Barred Red (Redbar) became a promising prospect. Time was saved in fixing the colour pattern of the breed by using Redbar males for crossing with specially selected New Hampshire females. Results ere so favorable in production and apparent vigor of early generations as to suggest greater emphasis being placed upon the development of this new autosexing breed. Accordingly a plan for improvement by crossing both ways by males and females to New Hampshires was extended last year. As time goes on, this technique of breeding improvement may be carried on with this autosexing breed, thus offering a very broad scope for utilizing good blood lines in New Hampshires for improvement of the Hampbars. Satisfactory egg production was secured in R.O.P. last year, while the larger entry appears still more promising this year.
The current shortage in supplies of heavy roasting chickens and fowl in Canada, and the comparatively firm prices of same, no doubt will encourage increased production. However, high feed prices require maturity or finish for market at earlier ages. It will therefore be earlier feathering, earlier maturing and faster growing strains of poultry that can provide material for profitable production. The New Hampshires have been setting the pace and are now being improved in meat type, reduction in broodiness, and persistence in production. The Hampbars have the advantages of autosexing and lighter pin feathers in the dressed carcass. The Barred Rocks and Rhode Island Reds are also being brought up to higher utility standards of meat as well as egg production to serve modern needs in the industry.
Much attention is also being given to the remarkable advances made very recently in the efficiency of broiler rations. Elaborate tests are being conducted, in U.B.C. nutrition laboratories, of A.P.F.*, antibiotics, amino acids, and other supplements or ingredients that stimulate rapid early growth in chickens. With better bred stream-lined chickens, nourished by better feeds, poultry meat production is gaining rapidly on egg production in economic importance.
Recent records made in the production of broilers and fryers in some areas have been truly sensational, adding many millions of dollars to returns from broiler production constitute as much as 80 per cent of the value of all agricultural products. While the accent seems to be on youth in the form of the young tender chicken, there is a great need, too, for increased production of big roasters and capons. More people really want to eat more chicken if the industry will only provide the right kind and quality.
*Animal Protein Factor
Because of inheritance, some birds lay eggs with poor shells regardless of how well they are fed. Even so, no bird can be expected to form shells of the quality she is capable of unless the feed she eats furnishes the materials necessary for maximum shell formation. Environment, diseases and physiological changes in the birds themselves also affect the strength of shells produced.
Our present knowledge of feeding indicates that there are four nutrients of prime necessity in the ration in the proper amounts for maximum shell formation. These four nutrients are calcium, phosphorus, manganese, and vitamin D.
Nearly 95% of the egg shell is calcium carbonate. The hen depends on two different sources of calcium for the formation of her egg shells. These are which is available in her daily ration; and that which is present in her bones, which she is capable of drawing upon for use in shell formation. Both sources of calcium enter into the shell of each egg produced.
Normally, if enough calcium is provided in the ration, calcium will be deposited in the bones in quantities sufficient to balance that withdrawn from the bones for shell formation. If insufficient calcium is provided in the bird's ration for normal shell formulation, she will continue to withdraw calcium from her bones until she is depleted as much as about 50% of her entire skeletal reserve.
Even though birds will draw on bone calcium for shell formation, if the ration does not supply their needs they will not withdraw sufficient to maintain shell quality. Birds fed rations containing too little calcium will produce shells, which become thinner and thinner. However, the shells will not become thinner to the point of shell-less eggs being produced. A lack of calcium in the ration will cause production to stop entirely before shell-less eggs will be produced.
Shell-less eggs or so-called "soft-shelled eggs" are, as a rule, not the result of faulty feeds, but instead of physiological imperfections within the bird. Soft-shelled eggs are often seen in outbreaks of Newcastle disease.
The requirement of the laying bird for calcium has been set by the National Research Council at 2.25% of the total ration. The entire amount need not be included in the mash. Experiments have shown that laying birds given access to such calcium supplements as hen size particles of oyster shell, clam shell, or limestone grit will supplement the calcium present in the mash with enough of the shell or grit to meet her particular needs for shell-forming materials.
Generally, laying birds receiving a mash containing 2.25 to 2.50% calcium with a calcium supplement available will be supplied with sufficient calcium for shell formation.
Role of Phosphorus
The role of phosphorus in shell formation is a minor one. There are little or no data available that show that the level of phosphorus in the ration influences the quality of egg shell produced.
The shell itself contains only small amounts of phosphorus. Phosphorus, however, is required for egg production. It is an important factor in the complex method whereby the bird uses bone calcium for shell formation.
Phosphorus must be present in the diet in order for calcium to be deposited in the bone. The calcium is deposited in the bone as a calcium phosphate compound. When calcium is withdrawn from the bone, the phosphorus is also withdrawn, but instead of the phosphorus being utilized as the calcium is, it is eliminated from the body through the droppings.
The National Research Council has established the phosphorus requirement for laying birds at 0.75% of the ration. The common practice is to include the entire amount in the laying mash. To do this, it is necessary to include from 1.1 to 1.3% phosphorus in the mash.
Such materials as steamed bone meal, defluorinated phosphate, and dicalcium phosphate have been used as supplements to increase the phosphorus level of the mash to the desired amount.
Adequate vitamin D, secured either through irradiation from sunlight or from the feed, is necessary if the laying bird is to produce shells of maximum strength. Although the egg is one of the few natural foods containing vitamin D, it is not a component part of the shell. Nevertheless, a lack of vitamin D will cause egg shells to become progressively thinner in the same manner as a lack of calcium will.
Vitamin D Necessary
Vitamin D is necessary in the laying ration if the bird is to be able to utilize the calcium and phosphorus, which are provided to her. The actual amount of vitamin D necessary in the ration is somewhat dependent upon the level of calcium and phosphorus in the ration. Inadequate levels of calcium and phosphorus can be compensated for to some extent by increased levels of vitamin D. Higher levels of calcium and phosphorus also tend to decrease requirements for vitamin D.
At levels of 2.25% calcium and 0.75% phosphorus, it is recommended that the ration contain 450 A.O.A.C. units of vitamin D per pound of feed. Birds having access to sunlight will not require this much in their feed. In fact, it is generally felt that the level of vitamin D in the feed can be reduced to about 225 A.O.A.C. units during the summer months.
Experimental evidence has been brought forth in the past few years to show that small amounts of manganese are necessary in the diet of the laying hen for optimum shell formation. It has been determined that a deficiency of manganese will cause reduced breaking strength of shells and an abnormal appearance of the shells when observed before a candling machine.
The exact role of manganese in shell formation has not been definitely established. Recent reports from the Texas Experiment Station indicate that there may be a supplementary relationship between manganese and vitamin D, if not enough of the vitamin is present in the feed. The data of these investigators indicate that laying hens require more manganese than laying pullets.
It is generally accepted that laying rations should contain about 50 parts per million of manganese. The ration can, as a rule, be brought up to this level by including eight ounces of a commercial grade of manganese sulphate in each ton of mash.
Our knowledge of the role of calcium, phosphorus, manganese, and vitamin D in the formation of egg shells does not necessarily mean that we can write the final chapter on the effect of feeding on shell formation. Generally speaking, the quality of shells produced by our heavy laying strains of birds is poor, particularly during the spring and summer months. That additional nutritional factors may be responsible, in part at least, for the summer decline in shell quality is considered a definite possibility.
The role of many of the minor elements and of most of the recently discovered vitamins in shell formation has not been investigated. It is quite possible that, as more research work is completed, a way will be found to improve shell quality by means of better nutrition.
The writer, Mr. Vickers believes there are some good arguments for the creation of a really good dual-purpose chicken. Straight egg-laying strains, he says, have only one leg to stand upon. As so have these recently developed straight 'broiler strains'. "What we want is a chicken with two good legs." This article was written for Poultry Supply Dealer, and appeared in Poultry Digest.
While inspecting flocks for a certain hatchery recently, I heard several flock owners complain to the hatchery manager that winter egg production of their flocks, even in those made up entirely of pullets was not satisfactory. One man went so far as to say that he hadn't made any money at all on his chickens, and was going to turn his laying house into a hog house.
Most of these flock owners had New Hampshires, many for the first time. None of them had been able to get over 60% egg production from their flocks, even though nearly every bird appeared to be laying. Apparently the stock simply didn't have the ability to produce heavily.
The hatchery manager was new on the job and not too well informed regarding the past history of the flocks in question. So he asked me if I could tell him what the trouble was, as we drove from place to place.
Well, I happen to know that last year his hatchery put out broiler strain New Hampshire chicks to these flock owners. The strain evidently just didn't have high laying ability bred into it. I have seen the same thing happen before. The question is: What are hatcherymen going to do about such situations?
There seems to be little doubt that strains, especially New Hampshires, selected and bred for their ability to grow rapidly make slightly more profitable broilers than those that have not been bred for rapid growth. Likewise, it seems that in many cased egg production has been largely ignored by breeders interested in developing broiler strains, with the result that such strains frequently are incapable of sustained high egg production comparable to that of strains bred for high laying ability.
And unfortunately, in the past, most of those who have bred their birds for egg production have pretty largely disregarded meat qualities of their stock.
Broiler raisers naturally are interested in strains that will be most efficient as meat producers. Unfortunately, such chicks have to be hatched from eggs produced by laying flocks; and these laying flocks are owned mostly by flock owners who must make their profits not from broilers but from eggs.
When broiler growers want one kind of chick and flock owners want another, obviously they can both be satisfied only with a chicken that makes a top-notch broiler and at the same time will lay heavily enough so that flockowners can make decent profits from eggs.
I sometimes wonder if we aren't placing too much emphasis at present on the importance of developing meat-type birds. With industry attention so strongly focused on meat qualities, egg production is being almost completely ignored. In my opinion w have become almost as "meat lopsided" as we formerly were "egg top-heavy".
The ideal all-around chicken, of course, would be one that would still lay lots of eggs, so that everyone concerned could make a profit on it.
Most people believe such a strain can be developed. It will obviously take longer to evolve a strain of this kind than to develop strains for particular purposes, because it would be a much more complicated job. Nevertheless, the differences between the egg production strains and the specialized broiler strains, with respect to meat qualities are not very great, as several recent tests have shown. And with a little emphasis and selection pressure for meat qualities some of our egg strains could probably equal, or nearly equal, the pure broiler strains from a meat production standpoint.
I know one hatcheryman in a broiler area who formerly produced pure, broiler strain New Hampshire chicks. Egg production of his supply flocks, however, was so low that he had constant trouble keeping flockowners. He solved his problem by supplying his flockowners with an egg production strain of New Hampshires, to which he mates males of the pure broiler strain.
Dual Qualities Result
He says the offspring are just about as good for broilers as the pure broiler strain. And the flockowners are much better satisfied because of the improvement in egg production.
It is my belief that meat and broiler quality can be improved more quickly and with less effort than egg production factors. Therefore, I believe a good egg production strain with reasonably good meat and broiler qualities can be more quickly developed into a good, all-around chicken than pure broiler strains with low egg producing ability could.
I know of one breeder who is basing his present work on this theory. He is selecting day-old chicks for rapid feathering again at two weeks, and he is weighing all chicks at 8 and 12 weeks of age.
I his individual breeding pens he is using only good egg producing females from good egg production families, that exhibited good average weight at 8 and 12 weeks of age.
No individual male is used that was not above the average weight of all males at 8 and 12 weeks. Furthermore, these males must be well fleshed and must possess good meat qualities.
I believe such a procedure will rapidly improve the broiler and meat qualities of his strain.
I believe an all-around good chicken can be produced. I believe it will be produced, and that the day of the one-purpose chicken is numbered. The latter has only one leg to stand on and what we need is a good two-legged chicken. To be sure, this is a day of specialization, but the specializing should be directed toward producing a good, all-purpose bird.
An all-around bird is what is needed in the great majority of farm flocks, and that is what is needed in broiler areas, too, if flockowners are to be satisfied and enabled to make satisfactory profits.
Some people have suggested that hatcherymen should produce both egg laying and broiler strains, and pay higher premiums to flockowners who produce the broiler strain eggs to compensate for lower egg production. This is another of those theories, however, which hatcherymen tell me simply will not work in practice.
Poultry husbandry is such today that considerable confusion and misapprehension are present where the grit requirements of domestic poultry are concerned. As a result large numbers of chickens receive the wrong type, causing ill health and suffering, and in not a few cases deaths occur. Two quotations from the literature will show the confusion present today.
- "It is interesting to note that this experiment indicates that limestone grit cannot be regarded as an efficient substitute for insoluble grit". E. T. Halnan (1946).
- "Limestone seems amply capable of serving in the dual capacity of furnishing the minerals for eggshell making and for whatever additional service grit may render in the digestive system." W. Ray Ewing (1947).
Two Types of Grit
There are two main types of grit, each different in function –
- Insoluble Grit – useful for its mechanical effects in the gizzard
- Soluble Grit – valuable for the calcium, which it supplies to the hen, after it undergoes solution in the gastric juices.
Neither of these two types of grit plays any functional part, as such, prior to our succeeding the gizzard proper. They are not, therefore, of any value in crop or intestinal digestion.
The supply of insoluble grit to poultry is generally made by the use of such substances as flint, quartz, granite, gravel, sand, etc.
In certain quarters there is some prejudice against flint as a grit for poultry because of it s shattering, splitting nature (due to its molecular structure) giving too many of its particles an elongated and sharply pointed nature – yet there is no doubt that more flint grit is used commercially in Great Britain than any other, but there is much to be said for the production and sale of a hard and permanent grit (cuboid in shape) and granite or gravel would appear quite satisfactory. Flint grit cost about 9/- a cwt. and the fact that it is available everywhere in graduated sizes helps to make it popular.
Function of Insoluble Grit
When present in the gizzard in reasonable quantities, flint-type grits have two main functions:
- to divide and separate food particles so that the digestive, enzyme-like secretions from the proventriculus and the mineral acid of the gizzard can permeate freely.
- grinding and crushing.
Both functions (a) and (b) are dependent on normal gizzard motility. When the gizzard contains both solid food particles and grit a "masticating" effect follows. Grass, leaves and grain undergo pulverization, and with each muscular contraction more vegetable cells are exposed to the action of the digestive juices. Foods of animal origin, including the "wings and legs of insect, worms, slugs, snails, fish and meat also break down mechanically under the grinding process described. There is little doubt, however, that as a result of gizzardectomy experiments, whereas this reaction is invaluable to most birds of a graminivorous nature, we now know it is not absolutely necessary for digestion in the domestic hen, and it is certainly unnecessary for certain carnivorous avian species. At the same time, although modern domestic poultry, when being fed on wet and dry mashes, meals and pellets or grains, do not necessarily require insoluble grits for grinding purposes, these substances do aid better food utilization, and therefore may play an economical and indeed important part in poultry husbandry. For example, in the case of young chicks on a diet consisting solely of pellets and water, whilst there is no need for insoluble grit, a proper amount may aid digestion, whereas an excess will cause indigestion. Whilst there is little doubt regarding the former, it is far better to let the chicks do without grit than to risk ill health through mismanagement. It is the regulation of dosage that is the most important factor to be considered.
Those in normal use comprise calcium-rich mineral compounds such as limestone, oyster shell, cockle shell, Malton fossils, rock phosphate, etc. Although in some countries there is a strong prejudice in favour of oyster shell grit for poultry, there is little scientific evidence t warrant this and any soluble lime-containing grit is suitable provided it does not contain unwanted or harmful minerals.
Function of Soluble Grits
On the general poultry farm, where the farmer mixes his own rations, lime-containing grits are used to supply calcium both for growth and egg shell formation. But in the case of commercial foods it is generally only the latter function for which soluble grit is required. For growth purposes sufficient calcium is usually added to chick and growers rations in order to balance the Ca:P ration, and this obviates the necessity of giving limestone grit. In practice, however, the giving of soluble grits is frequently recommended for poultry of all ages and with all rations, and results are often disastrous.
Harmful Effects of Flint-Type Grits
For your chicks in particular the use of flint grit ad lib may be fraught with danger, particularly if the total ration is not well balanced. Also if there is a shortage of calcium in the diet, or a wide Ca:P ration or if there is pica from a cause, there may well be an excessive intake of grit. This will be followed by an overloading of the gizzard, and some of the grit will overflow into the duodenum. This passes rapidly to the exterior with the faeces and in many instances a mechanical laceration of the small intestine occurs. Deaths are not uncommon, and ailing chicks show ruffled feathers and stunted growth, but such cases do not occur if the grit is given in restricted quantities at say fortnightly intervals; whereas the giving of flint type grit in hoppers ad lib, or in heaps in the brooder house runs is often dangerous. When the gizzard does not contain an excess of such grit the appetite for dry mashes is reduced, intestinal motility is increased and foodstuffs pass more quickly than normal to the outside. Post-mortem examination findings are of course characteristic – from overloading of the gizzard to the resulting enteritis. As treatment no further supplies of grit should be given for at least one month and then only if subsequent post-mortem findings show that the gizzard is nearly grit free. If cretapreparata 5 per cent is added to the diet for 7 days, its ingestion assists recovery, as also does chlorodyne, in medicinal doses. Once the diet has been corrected it is best to eliminate flint grit from the ration, providing the chicks are being reared intensively and are not being given feeds of grass or green food.
An absence of grit from the gizzard of poultry may lead to no harm whilst the diet contains no grass, otherwise impactions of the gizzard by grass leaves and grain (entwining themselves into a knotted mass) may occur. Portions of the entangled material may pass also into the small intestines, whilst at other times a complete occlusion of the pylorus is a feature of the malady. Occasionally a secondary cause, such as an impaired gizzard motility – possibly of Fowl Paralysis origin – is present. It should be noted that once the gizzard is impacting itself, then the crop also becomes full of additional grass, mash and leaves, etc., which soon turns sour.
On some occasions birds crave for grass, as seen in Pullet Disease, but often there is little or no clue as to the real cause for eating too much grass.
A heavy intake of grass, particularly semi-dried long grasses, may overtax a gizzard even when some grit is present.
Harmful Effects of Limestone Grits
In the writer's veterinary experience much harm is caused to poultry at all ages by a too free use of soluble lime-containing grits. At times, no doubt, the intake has been excessive, caused by a concomitant absence of insoluble grit, but generally speaking it follows its more or less unrestricted use for young chicks – birds in fact which are neither educated to its use, nor have any special need of its contained calcium. Its use ad lib may cause a special form of indigestion call by the writer "Lime Poisoning". D. S. Farner (1943) has shown that the gastric hydrogen ion concentration is reduced significantly by adding to basic rations calcium carbonate in the form of limestone grits, whilst an investigation at the Kentucky Agricultural Experiment Station (1935) has also shown that extra calcium carbonate retards digestion. Doubtless these two pieces of research have a direct bearing on the aetiology of so-called "Lime Poisoning."
In the writer's experience this malady is fairly common in Great Britain, due solely to the indiscriminate use of limestone as a so-called complete grit from hatching onwards.
Clinically, lime poisoning is characterized by a heavy culling rate, particularly in growing stock which should be on the point of lay; affected birds are "light" when handled and a general inspection of the droppings of the flock shows the passage of undigested food. (The limestone grit is, of course, in full evidence throughout the pens, and is available ad lib.) Post-mortem findings show semi-impaction of the gizzard; a catarrhal enteritis of the duodenum, which becomes more acute in the jejunum and is associated with the passage of grossly undigested food. Particles of wheat or maize add grass fibres may be clearly recognizable at all lengths of the gut. The exterior of the duodenum is often characterized by diffuse haemorrhages, but they are often limited to the muscular and sub-peritoneal layers. A characteristic yellowish pigmentation of the duodenal mucous membrane is often present, while the jejunal contents are frothy and clear. Intestinal parasites are secondary and variable. Manifestations of Fowl Paralysis, in one or more of its common forms, are also to be noted on certain occasions. During the past 15 years the writer has achieved considerable success in a number of instances in checking Fowl Paralysis by ensuring that once the diet is balanced no limestone grit is given until the birds are in full production.
It has been known for some time that there are a number of ductless glands in the body and that the secretions of these glands (and from others having ducts) play a very important role in the growth and development of the body. The action exerted by the ductless glands and from certain glands having ducts (the endocrine glands) is equally important in the functioning of the fowl's body as with the human species.
At the outset if must be admitted that our knowledge of the working of the endocrine glands is fragmentary – and moreover, that what knowledge we possess is not all, as yet, of practical importance to the poultry keeper. Nevertheless, the application of a small part of that knowledge has already indicated that substantial changes in certain commercial methods of management may take place. A brief sketch of other possible lines work on which these possibilities may be based will, no doubt, be of interest to the poultry keeper whose horizon stretches beyond the immediate problems of the day.
A survey of the whole field – limited as our knowledge is – would be too extensive for the scope of a single article, and the following account is therefore concerned with one aspect of endocrinology – the effect of the secretions of the sex glands, since it is in their field that practical application of our knowledge appears to have made the greatest advance.
The secretions of the sex glands appear to control the sexual characteristics of the bird. Thus, those secretions from the male organs result in the copulative habits of the male bird, the development of male plumage, the comb, wattles and the male voice. In the case of the female, the feminine habits and sexual characteristics derive from the secretions of the female sex organs.
A simple demonstration is the caponizing of the male bird leading to certain feminine habits and the shrinkage or depression of the male attributes, such as the large size of the male comb and wattles.
The secretions, or hormones as they are collectively called, are known as androgens in the case of the male, while those of the female are known as estrogens.
These terms cover several substances, but of major importance is the fact that a large number of substances having a similar chemical composition – and more important – having the same biological properties, can by synthetically prepared. Now the knowledge of the role played by these sex hormones suggested that some advantage might result from the treatment of fowl by androgens or estrogens.
It seemed possible that the injection of female sex hormones into hens or pullets might stimulate the female habit of egg production. A similar treatment directed towards the male might lead to feminine bodily characteristics of value in the table poultry industry, while treatment of the incubating egg with estrogenic substances (female sex hormone) might lead to the production of female chicks only.
It is probably known that the gonads or sex glands are very similar in shape until the sixth day of embryonic development. With the male the two gonads develop into two equally active testes or male gonads, but in the case of the female it is only the left gonad that becomes active on maturity as the ovary – the right remaining rudimentary. What the scientist endeavors t do is to change a genetic male, i.e., an embryo that would normally hatch as the production of inter-sexes – chicks showing the attributes of both mal and female. The several investigations seem to indicate, however, that some of the male hormone materials lead to ambi-sexual activities.
Treatment of genetic males with female hormone materials, i.e., estrogens, seems more successful. The genetic males produced from incubated eggs so treated appear to have developed the sex organs of a female to a lesser or greater degree. In the case of genetic females examples have been produced showing two incompletely developed oviducts, and in a case cited by Greenwood, the bird laid shell-less eggs.
It seems not at all impossible that in the not too distant future treatment of the embryo with female sex hormones (estrogens) may lead to the production of female chicks only – an obvious advantage from the viewpoint of the table egg producer.
No great attempt appears to have been made to ascertain whether a male bird can be turned into a female. The variation between the gonads in the case of the female appears to lead to some complication in trying to carry out this work. Injections with certain male hormone substances into the incubating egg have certainly led to stimulation of egg production and can be achieved by the treatment of the hen with female hormone material. One of the reasons may be the extremely complicated nature of the problem. A stimulation of one activity alone may not result in the desired end if other activities do not receive an equally strong stimulus, and it will be borne in mind that egg production is an extremely complicated process.
Nevertheless there is some evidence that the injection of one estrogenic substance leads to increased secretion of albumen, while another hormone – prolactin – the secretion of the pituitary gland that induces broodiness.
Cow manure apparently contains an androgenic (male hormone) substance, and the inclusion of dried cow manure in a normal mash has been shown to lead to depression of egg production. Dried cow manure with the androgenic substances destroyed included in a mash containing no animal protein did, however, materially improves hatchability.
One important point that is apparent throughout the work of most investigators of the problems is the fact that in most instances the changes induced are temporary. This is not surprising since in the normal bird the various hormones are being continually secreted. Until this difficulty can be overcome, it may from the financial viewpoint prove a limiting factor over the practical application of the work.
This short term effect, no doubt, led to the belief that short term feminisation of males would be of practical value for the table poultry industry, and might do away with the need for caponisation. The theory held was obviously that the stimulation of feminine behavior would lead to results identical with those reached by caponisation. Several treatments with estrogens – notably diethylstilbestrol – have been attempted. The treatment has been carried into effect with both male and female birds.
The work is still in the experimental stage and it is not surprising to find some differences of view held by the many workers concerned. With old hens opinion seems generally in accord with the view that no change in the carcass quality takes place.
With male birds varying opinions are held, some workers maintaining that no change in weight takes place but appearance and texture of skin is improved, others take the view that deposition of the fat – but not necessarily amount of fat – is affected, while still other investigators state that an increase in carcass weight is achieved.
Quite possibly these varying views arise from the different estrogenic materials used, different methods of implantation, and the varying ages of the birds. The length of treatment normally extends over about four weeks.
Obviously much more investigation is necessary and it must not be forgotten that complete absorption of the estrogen must be assured for the substances may be effective with the human consumer of the bird!
To sum up: In spite of our limited knowledge of the subject it is clear that the use of sex hormones may be of great advantage to poultry keeping in the future. Three attractive fields of research have been indicated and no doubt they will be of interest to the workers at the research centres recently set up in this country. The practical application of fresh knowledge in this field may be a possibility far sooner than many imagine.
An interesting theory was recently presented to us by an observer of our industry. During the past three seasons a malady has affected a great many chicks during their first two weeks of life that has been diagnosed as a kidney disease. Quite severe losses have been reported, in any event bad enough to warrant an investigation being undertaken by the University of British Columbia, so far without any great satisfaction resulting.
Our informant stated that it is only recently that our fish oils have been reinforced by synthetic vitamin D, and the period corresponds roughly with the advent of the kidney trouble. His theory is that the synthetic vitamin D, which is a coal tar preparation, may be the cause of the inflammation of the kidneys, and he cites the fact that manufacturers of the synthetic vitamins warn physicians not to prescribe them to patients suffering from any kidney complaint. He therefore concludes that there may be something harmful to kidneys and a percentage of chicks are unable to successfully handle this product. We publicize this theory in the belief that some research work would prove beneficial to the industry. It may be that a normally healthy chick would not be affected and that it is only the weak chick – that should not be alive – that succumbs to an intake of this synthetic product. We suggest that our universities undertake an investigation for the benefit of the industry.
As this is a meeting of men interested in hatching and selling baby chicks, let us start with a box of baby chicks as they arrive on the farm.
Upon arrival a baby chick is a bundle of possibilities and it is partly your duty as hatcherymen to see that the purchaser gets everything possible out of the chicks.
We are convinced that most losses in baby chicks are due to mismanagement and a great deal of these losses can be prevented by proper instruction, on the handling of baby chicks.
Baby chicks upon arrival should immediately be taken out of their box and put in a brooder which has previously been thoroughly prepared by cleaning and heating for 3 days before the arrival of the chicks so as to insure an even temperature of 95 to 100 degrees F. Baby chicks should be kept separate from all other poultry. A baby chick's first need is water; as it body is comprised of 55% water. Water is needed for the following purposes; as a solvent for food stuffs, transportation of food stuffs, to chemically aid digestion, in the regulation of body temperature and the elimination of body waste. Water is more essential to poultry than feed. A chicken will live longer on water alone than on feed alone. A properly balanced chick starter should be regularly fed.
All drinking fountains, feeding troughs and other equipment should be washed once per day in boiling water.
If there are any pullorum losses in the chicks, they will commence at about 2 weeks. Unfortunately there is nothing that can be done at this time to prevent these losses except putting strict sanitation measures into effect and immediately removing any sick or dead chicks. Be sure of your diagnosis when losses appear in your flock. There is operated by each province, a Provincial Laboratory where you may send sick or dead, preferably sick, chicks and chickens and obtain a proper diagnosis. Make full use of this service supplied by your Provincial Government.
Checking and Preventing Coccidiosis
From figures gathered from every province in the Dominion it is evident that there has been less pullorum chick mortality this year than ever before. In fact pullorum losses this past season have been negligible, but let us not be lulled into a false sense of security. We must still be on the alert for any increase in pullorum outbreaks.
The Coccidiosis danger period starts at three weeks of age. The Division of Animal Pathology, Science Service of the Dominion Department of Agriculture have just completed but not yet published a long and thorough study of Coccidiosis and it is their findings that certain of the sulpha drugs will control coccidiosis. These sulpha drugs however must not be used promiscuously in large amounts or for too long periods, as harmful results, such as chronic bleeding, upset nutritional balances, lack of egg shell, etc. may result.
The drugs, sulphamerazine and sulphamethazine will check coccidial infection even after it has progressed to the stage when bleeding has commenced. These drugs when given in smaller doses during the time when birds are exposed to infection will prevent disease.
The dosage of sulphamerazine and sulphamethazine for preventive treatment is one ounce per 30 lbs. of feed thoroughly mixed and fed for 6 days. It must be remembered that it is essential for birds to be exposed to infection while they are getting the preventative treatment; otherwise they will not become immune.
The amounts of drug necessary for curative treatment is one ounce per 15 pounds of feed thoroughly mixed, and treatment should be started at the first sign of bloody droppings and continued for three days.
These sulpha drugs if obtained by the poultryman at a cost of $18.00 per pound, and we hope this will be possible by next spring, can be used for either a three-day curative treatment or a six day preventative treatment at a total cost of less than .01c per bird.
Practical systems are now being worked out by the Division of Animal Pathology, and these will be available before the coming spring. These coccidiosis control measures will, when ready, be given adequate publicity and instructions for their use will be available to any one.
Pullorum Reduced to One Percent
Speaking now of pullorum control, we wish to emphasize that it is not accident that the pullorum reaction in hatchery supply flocks has been reduced from 20% at the start of organized pullorum testing to less than 1% today.
This sharp reduction in reaction percentage is the result of a carefully planned and closely followed control or eradication policy and we cannot emphasize too strongly your responsibility in seeing that these control measures are followed at all times.
How Percentage Should Be Figured
It is the custom in most provinces to figure the annual pullorum percentage on the final test figures of each flock. While this gives us the percentage of hatchery supply flocks at the start of the hatching season, it does not give us a true picture of the pullorum reaction in a province. To properly determine the effect of the control policy, all reactors in the first tests of each year should be used in figuring the provincial percentage of reaction and that percentage then compared to similar percentages of previous years.
We know what should be done for a sound pullorum control program, and so let us follow that program, but at the same tie we should now turn our minds to other diseases and problems of poultry. Let us attempt to work out sound practical programs for other diseases that are now just as important to our industry.
Hatchery Needs Four Departments
Turning to the hatchery, we must all realize that the chick hatching industry is now a main street proposition and every effort must be made to keep it where it is today. The chief function of a hatchery is to change the raw product, hatching eggs, into baby chicks. The steps in this process all follow in sequence and each step should be kept separate from each other; thus making necessary at least four separate departments-
1) Egg receiving room, which if necessary can also be sued for traying the eggs, but it is preferable to have a separate room for this purpose.
2) The incubating and hatching room, in which nothing but the machines should be kept.
3) Chick grading, boxing and shipping room.
4) The wash up room, where all trays and other essential equipment should be thoroughly washed after each use.
If brooding is to be carried on, it is absolutely essential that a separate brooder room with no direct entrance to the machine room be maintained.
Hatching Chicks Now Big Business with 9000 Approved Flocks
In Canada during the past year there were approximately 3,000,000 birds comprising some 9,000 poultry flocks, that were approved in order to ship hatching eggs to Canada Approved Hatcheries. This means that during the hatching season, approved hatcheries are the marketing agents for 9,000 Canadian poultry farmers who supply the hatching eggs for the poultry industry as a whole. In addition these 9,000 supply flock owners buy back chicks produced by approved hatcheries, so that hatchery operators are doubly responsible to their supply flock owners primarily for their initial raw product and secondly because they constitute a portion of their market.
The Servicing of Supply Flocks
The first essential to the success of a hatchery operator is the exercise of care in the selection of sound, progressive poultrymen as supply flock owners and then treat them as partners in his business, as indeed they are. It is also the duty of an approved hatchery operator to service his supply flocks.
A qualified hatchery service man visiting supply flocks regularly is in a position to advise owners of any needed changes in their program to produce better hatching eggs, and at the same time the hatchery gains the protection of knowing al the approved flock regulations are being followed.
Supply flock owners should feed a good breeding ration and start feeding it at least four weeks prior to the first hatching egg delivery. As most of the nutritional factors required for normal embryo growth are also essential for normal chick growth, high livability of chicks is closely associated with high hatchability of eggs.
To produce good hatching eggs there must be a sound breeding program and good flock management. Parasites can, for example, reduce hatchability; dirty eggs are a nuisance as well as a potential source of disease to the hatcheryman; poor shell texture does not enhance hatching eggs. All these and many other related problems can be cleared away by a qualified hatchery service man.
Flock owner meetings can and should be held, with a few short talks on mutual problems giving the flock owner an opportunity to have his questions answered and pointing out to him the benefits of better hatchability from a properly cared for flock. An insight into the hatchery operations and all they entail should be given the flock owners in order that they may appreciate the hatchery operator's side of the picture.
A circular letter service can be set up by the hatchery operator as a means of passing out to his supply flock owners new information, suggestions and ideas. The trend in chick demand and production can also be given as an aid to flock owners, along with interesting bits of information about individual flock owners, or any information about the hatchery and special orders that have been received. It will be found that every effort put forward to increase the flock owners' interest in the production of better hatching eggs and to promote confidence in the hatchery will pay good dividends.
It is the duty of an approved hatchery operator to operate the hatchery in such a manner that the hatching egg shipper gets the best possible returns on his hatching eggs ad that the chick buyers get the best possible chicks that can be produced. Good hatchery management consists of constant attention to a multitude of small details; the neglect of any one of which may lead to serious losses.
Infection and Sanitation
One of the important factors in producing quality chicks is sanitation and this is important in a hatcher as most diseases are spread through the presence of filth and dirt. In a hatchery with the constant flow of people, egg cases, eggs, chick boxes, chick incubator waste and in some cased feed and other poultry supplies, dirt is bound to accumulate and if this dirt remains, bacteria or disease producing organisms can thrive and spread.
Some of the most common sources of infection to hatcheries are dirty eggs, dirty egg cases, visitors, the use of used chick boxes, refuse from incubators, used feed bags, sick chickens and poultry coops.
A properly operated hatchery can overcome potential sources of infection and produce better chicks by the application of a few simple rules.
(1) Keep the hatchery clean and tidy at all times. Don't let supplies pile up on top of the machines and be dust collectors. After each hatch is taken off, wash up the entire premises using plenty of water and a good disinfectant. Keep the premises swept clean and free of cobwebs at all times.
(2) Have incubator refuse removed as soon as possible from the hatchery and if necessary to hold it overnight, hold outside in tightly closed refuse cans.
(3) Fumigate the machines regularly. It must be remembered that the sole function of fumigation is to create a disease free atmosphere in which the chicks can be hatched. Fumigation cannot destroy organisms inside an unhatched egg, nor will fumigation cure pullorum once established in a baby chick. Chick embryos are susceptible to formaldehyde only during the 24th to 72nd hour of incubation, that is the 2nd and 3rd days.
How to Fumigate Incubators
For proper fumigation use 1 ½ cu. Centimeters of formalin and 1 gram of potassium permanganate per cubic foot of incubator space (inside measurements). Machine to be aired after 20 minutes.
A simple and satisfactory fumigation program is as follows:
(i) Fumigate so as to expose each set to a gassing, being careful not to expose embryos to formaldehyde on the 2nd or 3rd day.
(ii) If separate hatchers are used, fumigate after transferring the eggs, but before any chicks have pipped.
(iii) Fumigate after each hatch has been taken off, but before any cleaning up has been commenced. This renders all debris harmless.
(iv) Do not allow visitors in the incubating room. Have a counter or public room where all business can be transacted.
(v) Do not brood chicks in the incubator room ad do not have the started chicks travel back through the hatchery on their way out.
(vi) Do not receive hatching eggs in the incubator room. If possible have a separate room for receiving eggs and other hatchery supplies. Tray either in the receiving room or a traying room. Do not take egg cases into incubator room.
(vii) Do not allow employees to wear the same clothes for flock field work and inside work.
(viii) Supply adequate washing facilities for all employees.
(ix) Do not allow sick or dead chickens or poultry coops inside the hatchery. If sick or dead birds must be examined, do this outside the hatchery.
(x) Have convenient washing facilities for chick sexers, and have them used regularly. Be sure that clean boxes are used for sexing and that chicks are carefully handled.
(xi) Operate the incubators in a manner that will hatch the best possible chicks. The present day incubator, as fully automatic as it is, still requires a competent and conscientious operator.
In general the higher percentage of hatch, the higher percentage of husky and strong chicks will be produced. Overheating, chilling and improper moisture in incubators at hatching time will result in poor quality chicks.
In the strictest sense artificial lights do not increase annual egg production, but merely influence the distribution of production, which makes it possible to get more eggs during the fall and early winter period of normally highest prices. For this reason, use of artificial lights can be planned to give desired results, dependent upon egg sales for market or hatching purposes.
It is usually unwise to light a flock of pullets being kept as a hatching flock, because the resulting stimulation of fall and winter production is made at the expense of a somewhat lower level of production in the early spring, when hatching egg demand is greatest.
Old Hens Under Lights
The lighting of the laying flock beginning in mid-August or early September is one example of greater production control that enables more net earnings. Lighting of old hens at this time, beginning at 4:00 a.m., makes it possible to postpone molt for a large portion of the flock and extend production for 45 to 60 days into the period of higher prices.
This practice as particular merit this year for the poultry raiser who wants to take advantage of price conditions to get the most net income from his production.
The smaller hatches this past spring and higher feed costs, which usually mean later maturing pullets and delaying fall production, all add up to strong demand and rising prices, and these extra eggs from old birds will mean greater income.
This result of artificial lighting is based upon findings of the Kansas State College of Agriculture and Ohio State University. Experiments established the fact that production increase was due to stimulation of the pituitary gland by the infra-red light rays. This stepped up glandular activity resulted in greater egg production, which brought about higher feed requirements and consumption. These facts made it possible to discard the earlier explanation of higher production due to a longer feeding period and greater feed intake.
Aside from this common use of lights for stimulating egg production during the fall and winter months numerous other values can put extra dollars in the poultry raiser's pocket.
Artificial lights may be used to reduce early chick and poultry mortality, to bring turkey breeder flocks into production more uniformly, and to increase the number of turkey hatching eggs produced per hen by approximately 10 eggs in the average season. They may be used to moderate the effects of extremely hot, as well as cold weather. Late hatched pullets can be brought into production earlier and at heavier weights, and late molting, "cream of the crop," breeder hens can be hastened into production to obtain hatching eggs earlier in the spring.
The research department of one prominent feed company has established a close relationship between the interval of time between hatching and the beginning of feeding and watering of turkey poults and livability and weight of these poults at 6 weeds of age.
Livability ranged from 91.7 per cent, when feeding was begun within 24 hours, to the lower figure of 73.7 per cent when delayed until 72 hours after hatching. The same experience is also common with baby chicks. Since time is so important, the use of all-night lights in the brooder house frequently makes it possible to shorten this hatching-to-feeding interval and to make added use of these critical "starting period" hours. This, in part at least, will offset the effects of unavoidable delay in getting chicks and poults on feed. Brighter lights, that is 40 t 60 watt bulbs, may be used for this purpose, to be followed, after 3 or 4 days, by 7 ½, 10, or 15 watt bulbs, which also aid in avoiding piling and loss from smothering if brooder temperatures accidently range too high or low.
Missouri College of Agriculture experimental results show that rate of chick growth is definitely retarded during hot summer weather. This is likewise true of turkey poults, though perhaps to a lesser degree.
Lights for Growth
Producers in the western and southern portions of the country, where daytime temperatures, for days on end range in the upper 90's or higher, have found that the use of dim – 10 to 15 watt – all-night lights in the brooder house helps to maintain growth. Feed and water consumption during the cooler night portion of each 24 hour period equals that of the daytime period and helps keep poults and chicks growing at or near the optimum rate through the 8th to 12th weeks.
Turkey Hatching Eggs in 30 Days
Turkey breeder hens that are approximately 7 months of age can be brought into production rather uniformly within 30 days after they are placed under artificial lights.
This fact proved important this past season to George Lewis of Quinlin, Okla. Mr. Lewis' flock of 400 breeders, which were lighted during the last few days of December, began laying in late January and continued to lay at a 50 per cent or better rate until sold on April 29th. Mr. Lewis sums up his first experience with artificial lights by saying that he sold 12 extra eggs per hen over the previous year in a season when hatching egg demand ceased 30 days earlier than in 1945.
Applying Lighting Principles
In stimulating egg production, intensity of light is the important consideration along with flock comfort. A safe rule is that of providing one 40 watt lamp for each 200 sq. ft. of floor space. The light should be located about 6 ft. from the floor and equipped with shallow reflectors 12 to 14 inches in diameter, to insure illumination of roosts as well as feeders and water fountains.
If reflectors are not provided, larger bulbs – at least 60 watts – are helpful. Much of the value of artificial lighting may be lost unless these principles are followed.
Intensity of light appears to affect turkey breeding flock production to a greater extent than is true with chickens. For this reason, 60 watt bulbs for turkeys more nearly insure desired results.
Flock comfort is important, and housing requirements vary with climactic conditions. In the southern climates where winters are mild, turkeys can be successfully lighted in a protected shed that is entirely open on the south. Some growers, with out door roosts, have successfully used flood lights mounted on poles 10 or more feet above the ground. These are arranged to light the roosts, feeders, and water fountains. Lighting is usually delayed approximately 30 days beyond the time when they might be used with greater housing protection from severe weather, which is generally of short duration.
Turkey breeder hens respond to light stimulus about 2 or 3 weeks sooner than the toms. For this reason, fertility must be protected in these first eggs by lighting toms 2 weeks before the lights are used on the hens, if both sexes are of the same age. Oklahoma College of Agriculture results indicate that toms that are from an earlier hatch, and consequently 30 or more days older than the hens, do not require this special consideration.
Begin Lights Gradually
Lighting of laying flocks should be started gradually and the lighting period lengthened 10 to 15 minutes per day until a 13 or 14-hour total light or feeding period is attained. Once begun, lighting should be continued until normal daylight approaching this number of hours prevails.
The use of automatic time switches in turning on the lights in the laying house will be found helpful. It avoids the necessity of being present in the house to turn on the lights. When an automatic time switch is used, provision must be made the night before – in the case of early morning lights – to have water available as soon as the birds come down from the roosts. This means, in wintertime, having water heated in the fountains.
Feed and Water Important
Satisfactory results, that is, higher production and an increased or maintained rate of growth, are related to higher feed intake. For this reason, the feed supply must be adequate and readily available. The water supply is of equal importance. During the winter months, provision must be made for an abundant water supply with a temperature range of 55 to 65 degrees F. Unless the chill is removed from the water and the supply is adequate, the results are likely to be disappointing.
National Poultry Digest from A.P. Journal
Coccidiosis as a severe disease is largely due to the development of specialized poultry raising. Responsible for it are: (1) the large rearing unit; (2) limited range; (3) continuously used range; (4) proximity of poultry farms and (5) increased trafficking in fowls.
His statement does not signify that specialized poultry farming is doomed to failure because of coccidiosis. It does, however, emphasize the necessity of recognizing the importance of this problem and becoming adequately informed.
The Cause – A small parasite distinguishable only under the microscope has been established beyond question as the cause of coccidiosis. Various forms of mismanagement or feeding of the flock, resulting in lowered vigor, are often regarded as primary factors in the production of the disease, but erroneously so. There is so much experimental and field evidence to disprove these assumptions, that they would not be worthy of mention here if it were not for the fact that many interested in poultry still cling to such misconception. It should be obvious that these muddle the situation and stand in the way of successful control.
Kinds of Coccidiosis – At least six kinds of coccidian are found in chickens, five of which affect particularly the small intestine and one the ceca and rectum. One is capable of causing severe bleeding from the ceca and the rectum, another from the small intestine. The remaining four as a rule cause slight or no bleeding, but do cause excessive amounts of mucous or slime in the small intestine and droppings.
The Nature of the Parasite and the Disease – When the fowl eats contaminated material the parasite gains entrance and passes into the intestines. In the meantime the parasite undergoes various changes and finally emerges in an egg form, or what is known as an oocyst. It then passes out in the droppings. This stage is not capable of producing disease. The fresh droppings from an infected fowl will not produce coccidiosis.
After being passed in the droppings, the oocyst undergoes a change, it proper conditions of moisture, air and temperature are provided. At this stage the parasite is capable of producing disease.
About four to six days, depending upon the kind of coccidiosis present, are necessary for the parasite to attain much development after being consumed. During the succeeding few days, heavily infected fowls discharge millions of oocysts in the droppings and thus expose others to infection.
Severity of the Disease Dependent Upon Number of Parasites Consumed – The number of oocysts consumed determines the severity of the disease. Fowls infected with small numbers appear perfectly healthy. Young fowls infected with a large number for the first infection regularly die with the disease in the case of the bloody types. Older fowls may show considerable cecal hemorrhage or bleeding and recover, but are not so likely to recover with small-intestine infection accompanied by bleeding. The fact that severity of the disease is determined by the number of coccidia is of considerable importance, as it means that reducing the number serves as a control measure. This is accomplished by sanitation. Since the oocysts pass out in greatest numbers during the first week after symptoms develop, the value of frequent cleaning during that period is obvious.
Method of Distribution – The parasite may be carried mechanically on the shoes, by flies, birds, used brooder equipment, which has not been thoroughly cleaned, streams, or irrigation ditches. Used unsterilized feed sacks may also act as a carrier, but are probably not a frequent source. In other instance the purchase of infected fowls is a source of infection. It is highly important to remember that mature fowls provide a very likely source of infection for your stock on the same farm. Droppings from the mature fowls, adhering to the attendant’s shoes, perhaps afford the most common means of carrying the parasite to the brooder stock.
Seasonal Conditions exercise a distinct influence on the development of coccidiosis. This is due to the fact that moisture and warmth provided during the spring and summer months permit of rapid and regular development of the oocyst to the stage, which is capable of producing the disease. Therefore, it more frequently occurs in severe form at such times. It is possible for severe coccidiosis to develop during the winter. When this occurs the source of infective oocysts is likely to be soil or material contaminated during the warm season or contaminated material during the warm season or contaminated material kept warm by the brooder stove.
Symptoms and Diagnosis – The symptoms in many cases of coccidiosis may not differ from those of a number of other diseases. This is particularly true when moderate infection exists. Where very mild infection occurs there may be no outward evidence. These cases can be diagnosed only with the aid of a microscope. There are times, however, when the average poultry raiser could hardly be mistaken in making a diagnosis.
Severe sudden outbreaks of cecal and sometimes small intestine coccidiosis are accompanied by the passage of distinct amounts of pure blood in the droppings. Young fowls affected with severe coccidiosis may die suddenly, without any symptoms having been noticed other than a pale comb, and a slight amount of blood on the vent fluff. Fowls dying under such circumstances may be in perfect flesh and show no symptoms until a few hours before death. They should be examined and the condition of the intestines noted. Such fatal cases of coccidiosis will often show the ceca or blind intestines bulging with pure blood, or in other instances such material will occur in the small intestine usually some distance below the gizzard. When the small intestine is so affected, it is common for it to be distinctly enlarged where the infection is most severe.
If the infection is moderately severe, the fowl will usually be droopy for several days up to a week or two, lose weight, and die during this period, or gradually show less symptoms and possible come back to normal weight. When many fowls in growing flocks appear droopy, and no other cause for disease can be determined, it is usually the safest plan to conclude that coccidiosis is the cause the apply sanitation accordingly.
Effect Upon Fowls of Laying Age – Fowls, which have not been infected during the rearing period, may be disastrously affected in the laying-house. Such flows consuming large doses of coccidia may show a slight to complete lack of egg production with six kinds of coccidiosis.
Coccidiosis and Paralysis – Paralysis is not infrequently stated to be brought on by coccidiosis. Since coccidiosis is so widespread it is not at all surprising that the two are frequently found in the same fowl. This does not signify that paralysis is due to coccidiosis. Paralyzed fowls may show large numbers of coccidia or none at all. This does not prove that coccidia are or are not the cause of paralysis. Fowls, which are free from coccidiosis, may have been infected in the past and in fowls, which are infected the parasites, may have no relationship to the paralysis. Substantial evidence at hand contradicts the hypothesis that paralysis is due to coccidia.
Prevention – “Sanitation is the foundation of coccidiosis control…. The inauguration of sanitary measures on an economic basis cannot be expected totally to eliminate coccidium infection, but they should result in holding infection down to a low degree, and permit of successful rearing.” These statements, made a number of years ago, are still consistent with the known facts.
Rearing fowls absolutely free of coccidiosis is highly undesirable if they are later to be kept under average commercial flock conditions. Such fowls would then be disastrously affected, so far as mortality and egg production are concerned, if they obtain large numbers of the parasite. Management factors, which allow the fowls to consume small doses during the growing period, are more likely to prove satisfactory. This by no means constitutes a recommendation for the use of methods generally recognized as insanitary.
Soil Conditions – Well-drained soil provides the most suitable land. This type dries out more readily and therefore assists in preventing development of the oocyst. Those, which do develop, are likely to die more quickly in dry soils than in damp soils.
The common practice of plowing the yard and growing a crop is to be recommended, but this cannot be relied upon to rid the soil of all coccidia. Annual plowing and leaving the yards idle for three or four years will probably result in practically all of the oocysts being destroyed since they would, during such time, be subjected to drying, which is very destructive to them. Where only one or two yards are provided, it is perhaps best not to plow at all, but to sweep the yards and haul the sweepings away. Plowing or spading the yards during an outbreak only serves to encourage the disease.
Types of Brooding and Equipment – The colony brooder, which is moved to new land, offers one means of controlling coccidiosis. Until recent years it has been the most accepted method of brooding to control intestinal parasites. This method has the disadvantage of high labor cost.
The permanently located brooder provides a particularly desirable type of brooding from the standpoint of convenience and labor. It is frequently open to objection because of its tendency to aggravate the development of coccidiosis.
In order to overcome the objection to the permanently located brooder, because of its favoring intestinal parasitic diseases, an artificial yard is sometimes used. This commonly consists of concrete or wire netting. Such a yard preferably extends the length of the brooder. It may be up to about 20 feet in width. The wire yard does not require frequent cleaning. While the concrete yard requires more frequent cleaning, it gives some opportunity for the fowls to acquire coccidial infection in mild form and to develop immunity. Having such a yard permits of cleaning it as thoroughly as the house and with slight labor. It is desirable to have the concrete yard sloped about eight to ten inches away from the brooder. It may be covered with sand or not, as desired.
One should not conclude that the concrete yard itself eliminates the losses. It merely provides suitable conditions for assisting in prevention and particularly for control when a severe outbreak occurs. It also assists in controlling other intestinal parasite diseases, especially roundworms and some tapeworms. As soon as brooding is completed, the fowls should be moved to range houses provided with wire floors high enough to prevent access to the droppings.
Drinking vessels placed on wire-covered or slatted frames will prevent access to moist places and will prevent the birds from consuming moist droppings. Wire floors over the entire brooder floor are undesirable. Coccidiosis may be entirely prevented by such equipment and if the fowls are placed on litter or soil later, serious coccidiosis may result. If one must resort to the use of such equipment to control coccidiosis, it would perhaps be preferable to go out of the business.
Range Conditions – Flocks on range present a difficult situation when seriously affected with the disease. Under such circumstances the houses should be moved farther apart to provide to flows with increase range. This reduces the degrees of contamination in the soil and accordingly the possibility of severe infection.
Treatment is of secondary importance, and can be recommended only as a means of making the best of an already bad situation, not as a routine preventive. Coccidiosis occurs in spite of any treatment, which has been reported. Feeding a ration consisting of about 20 per cent powered skim milk or buttermilk assist s in controlling cecal coccidiosis accompanied by blood. When this amount of dried mil is given, an ample supply of water must be provided, as considerably more is consumed than normally. It is advisable also to provide more driking space.
Control of Sudden, Severe Outbreak – When outbreaks of this nature occur involving bleeding from the ceca, the above mentioned milk feeding is advised to be continued for a week or ten days. Milk feeding may have no value for the control of coccidiosis of the small intestine. Its use offers definite objections from the standpoint of causing the droppings to become more liquid, thus favoring development of the oocysts in the litter. The following, which is essentially the so-called “Wisconsin” ration, may be used as an all-mash ration for the control of cecal infection:
Ingredients Parts by weight
Ground yellow corn 80
Wheat middlings 20
Bone meal 5
Limestone grit 5
Fine salt 1
Dried milk (skim or buttermilk) 30
Daily cleaning of the house is an advantage and the yard should be swept daily until marked improvement in the flock results.
If the weaker fowls are separated from the others, they do much better, the deaths are less, and the well fowls are less likely to become infected.
Moist places frequently occur where the fowls drink. Special precautions are taken to eliminate these moist places during warm weather and near the brooder stove at all times.
Flocks showing a severe outbreak can sometimes be handled to advantage by taking the cockerels out and placing them in fattening crates with wire bottoms so that the droppings pass through and cannot be reached by the fowls. This management alone will prevent further losses other than those already severely infected.
Additional heat is necessary during acute outbreaks, particularly when feeding liberally of milk or milk products. More careful observation is necessary to prevent losses due to huddling.
There is no more interesting chapter in the history of the rise of the poultry industry than the sensational progress made by the people of Japan. The records show that they accomplished more over there in the five-year period 1925-1930 than we have in this century to date. Of course, the alert Japanese learned much from us when in 1927 and 1928 they came over to inspect and study the methods that were responsible for the world’s record stock of British Columbia and the Pacific States to the south. Encouraged and assisted by a sympathetic and progressive government with a real policy of improvement, they were not slow to secure the very best of the high record bloodlines of this continent. They accomplished this because they were willing to pay a good price for stock. Through the government farms and departments of agriculture and education in Japan this blood was multiplied and distributed to the farmers on such a comprehensive scale as to literally transform the poultry keeping from and insignificant sideline in farming into one of the most important branches of agriculture.
Figures from official records indicate an increase of 12 million head of high producing poultry in the country from 1927 to 1932. Egg production itself was raised from an average of 107.2 eggs to 122.8 in the same period. This the highest average secured in any country in the world. Higher averages are obtained in some districts but not over a nation as a whole. This is all the more remarkable when it is considered that the poultry population of Japan still includes a considerable proportion of the native breeds like the Nagoya and other less productive ones. Such production is pretty certain proof of the efficiency of the methods practiced in Japan. As a matter of fact there appears little doubt that these thorough going people have learned practically all that Occidentals had to teach them and “then some”. Ample evidence now exists to show that in ne important new art the Japanese are three years ahead of the poultrymen in this country. This discovery is the determination of the sex of baby chicks by differences in the rudimentary copulative organs, or particularly the cloaca.
The Japanese got into the same trouble as our poultrymen with regard to surplus Leghorn broilers. Conditions in Japan were ever worse in this respect than in this country in 1929. There was practically no market over there for the tremendous numbers of these young cockerels produced through the rapid increase of the Leghorn breed in connection with the government’s big ten year program for increased production. Japanese scientists came to the rescue as they perfected their technique in sex determination. As far back as 1925 Dr. Masui of the Veterinary Division of the University of Tokio published a report of certain differences that he discovered in male and female chicks. When more advanced work was reported in a paper on “The Rudimentary Copulatory Organs of the Male Domestic Fowl and the Difference of the Sexes of Chickens” world wide interest was created in the important discovery. It was not considered to be feasible, however, from a commercial standpoint and also because of the time required to examine the chicks and the danger of injuring the young bird in the process.
It was not known by Dr. Masui or his co-workers in the early stages that chick sexing could be made practical for hatcheries or poultrymen. However, through the indomitable application of such practical pioneers as Kojima the practice was found to be commercially feasible. By intensive study of Dr. Masui’s method and the examination of the copulative organs of older chicks of 60 days of age he became familiar with the differences in the sexes. By comparing the organs of younger 30 days old and still younger chicks Kojima gradually improved his technique and familiarity with the organs and their differences to a point where he could distinguish the sexes at a day old. He also became able, through continued practice over a six months period during which he handled and examined thousands of chicks of different ages to make the examinations and decisions quickly.
Many others, like Sakajiyama have followed the example set by Kojima and have become practical teachers of Dr. Masui’s method of chick sexing. Meanwhile, Dr. Masui and Dr. Hashimoto have carried on their research on differences in different breeds and strains of chicks and other phases. The most recent findings are embodied in a book, which is now in the press. The previous classifications showing the different types of male and female chicks according to the presence or absence of genital eminence in the cloaca, as described in the Japanese textbook, are presented for students in the New Edition in the English translation.
Introduction of Chick Sexing into America
Considerable skepticism existed in England and on this continent regarding the commercial feasibility of chick sexing until recently when the Japanese expert Yogo gave his practical demonstrations. In Japan, the work, which has been developing ever since Kojima had such success in 1929-1930, is now carefully regulated for the most part by important organizations. The chief of these is the Japan Sex Propagate Association which consists of important scientists and officials in Japan, and which has received strong support from the Japan Poultry Journal. Mr. Takahashi, the owner and publisher of the Journal and an important teacher and investigator in his country, is president of the association, and Mr. Yamaguch, who is so well known in this country, and who is associate editor of the journal, is a director. The sexing experts themselves make up the principal rank and file membership in this professional organization.
Chick sexing in Japan is on a well organized educational and professional basis. Training schools have been conducted there for years in important poultry and hatchery centres. Students train for diplomas of third, second and first class Standards. Beginning with Thirds they gradually work up to the higher efficiency of speed and accuracy. A good many fail to qualify but already there are over 100 experts holding First Class Certificates in Japan. These men and women (there are 30 duly qualified young women experts in Japan) have shown in examinations that they can sex chicks at the minimum rate of 100 Leghorn chicks in 30 minutes, and with an accuracy of over 92 per cent. Most of them exceed these marks, especially after practice. The hatcheries employing such experts may safely guarantee that the sex of the chicks sold as pullets will be 90 per cent correct.
Although chick sexing was bound to be shown in this country soon, it was fortunate that the progressive Chick Sexing Propagate Association donated as a prize to the Grand Champion chick sexer of Japan a free trip to America. The Central Contests are held every year in Japan to stimulate competition and create interest in the outlying districts where the preliminary contests are held. Under the management and direction of Mr. Yamaguch, as is so well known now, demonstrations were arranged for and held this last spring at the University of B.C., Oregon Agricultural College, University of California and many hatcheries in different centres on the Pacific coast.
Every practical poultryman who does not cater to a special meat market knows what a nuisance the young cockerels are. The extra equipment, heat, space, labor and feed required just to rear to the age where sex can be detected, or they are fit to be “shot” into the market makes if a very expensive proposition. The expense appears to be superfluous, too.
If the cockerels could be marketed at a fair price when they were ready the trouble would be worth while. Even then their very presence would militate against the welfare of the pullets. So few commercial poultrymen, especially egg producers, make anything out of broilers that the more completely and the sooner they can be removed from the flocks the better.
It is from the standpoint of disease and the added menace brought about by brooding and rearing two chickens where only one is needed or ought to be that the greatest advantage would appear to accrue from chick sexing. The evils of overcrowding, in its stunting effects on birds, the unfair chance that the pullets have in competition with the more vigorous cockerels for feed; the feather eating, cannibalism, piling up; greater danger of infection from B.W.D., Coccidiosis, worms and paralysis and many more sanitary conditions or the absolute reduction of numbers as a safeguard. Chick sexing, which permits the egg producer to purchase just what he wants, viz., pullet chicks, looms up as a very useful aid in management problems and fighting the disease menace.
A New Profession
Boys and girls between the ages of 18 and 24, according to experience in Japan, will be attracted into this new and lucrative profession. A little calculation will show their earning possibilities with fees at one cent a chick, and experts capable of sexing from 3000 to 5000 a day.
While these laboratory demonstrations were eminently successful in showing the extreme accuracy and speed with which chick sexing could be done by a first class expert of Yogo’s caliber, the practical work done for hatcheries was still more convincing. The star example was at the Bolivar Hatcheries where 25,000 chicks were sexed by Yogo in four days. A check of these birds at 5 and 6 weeks revealed only 39 cockerel chicks out of one large lot of 11,800 pullets or an error of less than one third of 1 per cent or an accuracy of 99.7 per cent, which is incredibly high. In the case of the cockerels the error was less than 1 per cent. It is reported that one poultryman who purchased 2000 sexed cockerel chicks and who expected to do well on the deal wasn’t so enthusiastic about it when he finally counted all of the pullets, which he could find.
In one lot of 500 sexed cockerels kept and fed by the Washington Co-operative Hatchery at Bellingham, one lone pullet was discovered later. In answer to a questionnaire sent out by the Co-op. to six of its members who had purchased sexed pullet chicks (2850 in number) the losses in brooding were found to be very light. The customers were well satisfied with the chicks and the majority were enthusiastic about chick sexing, promising to purchase nothing but sexed pullet chicks next season if they were available.
A very successful demonstration was given at the International Baby Chick Convention at Grand Rapids, Michigan, on August 8th, last, before over 1000 commercial poultrymen of U.S. and Canada. Before this assembly Yogo sexed 100 chicks with 100 per cent accuracy and on the speed test he sexed 200 chicks in 13 minutes and 27 seconds. A profound impression was created in the minds of these progressive hatcherymen, and a good many of whom turned out more than a million chicks in a year and who are appreciative of the importance of such a revolutionary practice. It was impossible to satisfy the demand or the demonstration and reservations were made by the hatcherymen for all available experts for the coming season.
Service to the Industry
It is not necessary to dwell upon the surplus broiler problem at this time. The writer has found it to be even more serious in other parts of this continent than in British Columbia. Poultrymen everywhere have sought to be relieved of it for years. Breeding sex-linked varieties has in some places been adopted to enable the detection and separation of the male from the female as baby chicks. This practice has attained considerable vogue in England and in the New England States. It does not meet the situation, however, on a large scale and leaves the White Leghorn entirely out of its sphere.
While records as high as 8,000 to 10,000 chicks have been made by experts in Japan, a good commercial average would be 4,000 to 5,000 chicks in an eight hour day. The work requires concentrated scrutiny of the eyes and exacting technique of the hands so that excessive speed is hard on the operator and does not make for the highest accuracy. In a hatching season approximately 100 days at least 300,000 could be handled by one expert.
An important part of the technique is the way in which the chick is held. The chick should be held firmly but softly so that the fingers and hand may be coordinated as light pressure is applied to the abdomen of the chick and the cloaca inverted and its folds exposed. The genital eminence of the male can be seen as a whitish projection when the vent has been properly opened, whereas in the female the folds and membrane do not show such a raised organ. Since the vent is very small and folds smaller very sharp eyes and strong eyesight are necessary. Whereas young people of from 18 to 24 years generally have the keenest eyesight and have the best chances of success in learning the art, it was really older men who perfected the art in Japan. Anyone with keen senses of touch and eyesight may become proficient. In any case it requires much practice, the use of many chicks and continuous reference to the text book to attain efficiency in separating the sexes.
Chick sexing has made its debut in this country and proves its worth at once. Henceforth it will be possible through its adoption by hatcherymen to supply poultrymen with the pullet or cockerel chicks as required. Poultrymen will produce better pullets at lower cost even when they pay twice as much for pullet chicks as for mixed chicks. The destruction of many young broilers will relieve the broiler market and permit of better prices for all market chickens. Broiler specialists will supply the market with chickens of better quality. Everyone concerned will benefit from the adoption of chick sexing, and work with good remuneration will be provided for many of our Canadian young men and women. Millions of extra chicks will be required too for the schools. It all looks like good business for the poultry industry.
When we first published the C. P. Feed formulas, last October, it was a question in our minds whether poultrymen preferred to mix their own feeds or to purchase them ready mixed. We knew how good the feeds ere and that the best possible results could be expected. Now, after three quarters of a year has gone by, from the letters we have had and the poultrymen we have talked to, there is no doubt that the Supplement has popularized the home mixing of mash. With all the small ingredients, and incidentally the most important, in one bag, it is a simple matter of make up any formula suited to individual requirements. The actual combination of ground grains is relatively unimportant. They can be regulated according to market prices, the seasons and class of stock.
In the Supplement we aimed to include every necessary element in which the grains are deficient. Thus, we have animal protein and a high percentage of organic minerals. Vitamins A and D are also present. If birds were kept under natural conditions, conditions that they would instinctively choose, and were allowed to live their lives in their own way, we would not have to supply them with any proteins or minerals or vitamins. Things being as they are, necessitating the keeping of several hundreds of birds to the acre, sometimes totally confined even, if we don't supply them with every element that nature intended them to have, we are courting trouble and we usually get it.
The ingredient that always causes comment is the dehydrated kelp. Some people have never heard of it being used for poultry and still others do not know what it is. Kelp is seaweed and supplies come to us principally from the Pacific Ocean. The plant grows in profusion only in certain locations along the Pacific coast where there is the proper combination of water depth, water temperature, atmospheric temperature, currents and rocky bottom. One strange characteristic is that kelp does not take root in the ocean bottom, and always grows from rocks to which its many roots attach like claws, forming heavy masses.
From these rocks the plants grow to the surface of the ocean 60 feed or more above and then develop along the surface until they reach an average length of 120 feet at maturity. The water in which the kelp grows is so clear that the bottom of the ocean can be clearly seen. Kelp is harvested by a large boat carrying special equipment. This harvester moves slowly through the kelp beds, while reciprocating knives, like those on a grain harvester, cut a clean swath ahead of the boat. After the kelp has been cut, it is picked up by a conveyor which discharges it into the hold of the harvester, When the boat has been loaded with freshly harvested kelp, it returns to the manufacturing plant where it is dehydrated and ground.
Now, as to the value of kelp for feeding poultry. It is well known that the minerals in the land are gradually washed, by rains, into rivers and find their way to the sea. Very gradually, a little each year, the land is yielding up its mineral content to the sea so that today, in many parts of the world, the land has become woefully deficient in the minerals vitally necessary in maintaining perfect health. Plants grown on land that ordinarily have the ability to store up these valuable elements are unable to do so if the elements are not present in the soil. Therefore, we must ask the sea to yield up some of its abundant store. Fish contain some of these vital elements but the richest source is found in plants that grow in the sea and so we use kelp for our supply.
The remarkable ability of the giant brown kelp plants to absorb the essential minerals from the ocean and to concentrate them in vegetable form gives kelp meal great value in animal nutrition. These digestible mineral salts constitute more than one third the weight of kelp meal and they are several thousand times more concentrated in the kelp plant than in the ocean water. The variety of minerals in kelp is as important as the digestible, vegetable form in which they are present.
The more important essential minerals of kelp are vegetable Iodine, Iron, Copper and Manganese. Prominent among its other mineral constituents are Calcium, Phosphorus, Sulphur, Sodium, Potassium, Magnesium and Chlorine. These essential elements are usually very deficient in land grown feedstuffs. Such a combination of minerals in practical concentration cannot be found in any other plant. The extraordinary amount of vegetable iodine is one reason why it is such a valuable foodstuff for poultry and cattle. The real value of iodine for poultry is only beginning to be realized. It is known to assist in the assimilation of calcium, promoting a better bone structure, and it is usually found that birds fed on kelp eat less food, the supposition being that because of the action of iodine, working through the thyroid gland, greater assimilation of the digestible particles of the food takes place.
It is also acknowledged that a supply of kelp gives greater resistance to disease, and this, in itself, is worth the consideration of poultrymen.
Because kelp is very high in minerals does not mean that it is a complete mineral feed in itself. Calcium and phosphorus in greater quantities than are found in kelp need to be supplied to poultry. The Supplement includes calcium carbonate (ground oyster shell, clam shell or limestone) and the bone meal and meat scrap supplies the phosphorus.
There is no mystery about mixing good feeds. It is something that every poultryman should become acquainted with. The successful feeder is he who knows how to ring the changes, who senses the coming needs of his birds and is able, through knowledge of the value of foodstuffs, to maintain his birds in the very finest condition throughout all the seasons.
The opening years of the twentieth century have witnessed a tremendous advance in the science of nutrition, due in large measure to the discovery of vitamins and their role in the normal life processes. In the field of poultry nutrition, probably the most important event of period has been the discovery that the feeding of cod liver oil would make possible the rearing of chicks in confinement – a contribution which immediately opened up unlimited possibilities, both to the poultry keeper and tot the student of nutrition. Following close on this discovery came the development of the “all-mash” system of feeding, which is now adopted as standard practice, not only for chicks but in many cases for growing pullets and for laying hens. By means of all-mash feeding the poultry keeper can cut his labor costs, improve sanitation, and control feed consumption, while the research worker is enabled to conduct more careful studies with chicks under laboratory conditions.
With the introduction of satisfactory methods of rearing chicks indoors, there has come about a marked change in general feeding management, which threatens to revolutionize the entire poultry industry. Commercial plants are now raising their chicks in large units, closely confined in electrically heated brooders, built like apartment hotels – a system which involves a minimum of floor space, a minimum of labor and better control over the factors which contribute to the welfare of the flock. Many poultry plants also are expanding upwards instead of outwards, and laying-houses may tower to six stories in height, the birds being confined without access to yards throughout their whole life. A still further development of the confinement system of management is to be found in the new method of housing adult birds in “laying batteries” where hundreds may be cared for in a relatively small space, each hen being confined in an individual cage. Trap-nests are done away with, cleaning becomes automatic, and each bird can be observed and her record checked, with the utmost ease and accuracy. Results of such methods show that with good sanitation, careful management and a satisfactory ration, egg production goes up, mortality goes down, vigor and health are maintained and feed costs are reduced.
In the days when poultry keeping was entirely a farmyard proposition, when feeding was based principally on tradition and expediency, and when a touching faith in nature was the keynote of the system, such things as free range, open air, exercise and dust baths were considered the all-important essentials. Some of these, of course, are still highly valuable assets, provided they are not accompanied by soil contamination and other danger, but for modern commercial “egg factories” they prove to be cumbersome, expensive and risky, and are thus being replaced largely by the various artificial substitutes which science has devised. “Natural methods” served admirably for small flocks which were not exposed to the strain of heavy production and the hazards of contagious disease and parasites, but for commercial flocks of today, which must make a profit in the face of strong competition and low prices, factory methods have to be adopted and business principles applied, so as to maintain efficiency and cut production costs.
In the realm of research in poultry nutrition, there have also been dramatic changes since confinement rearing has ben introduced and feeding methods have been simplified. Electrically heated battery brooders make possible the rearing of large numbers of chicks in the laboratory, where heat, light moisture and ventilation are under control; where feed intake can be measured and growth rates recorded; where strictest sanitation can be observed and contagious disease eliminated; and where every pen can be kept under close and continuous observation.
Since these methods of scientific study have been adopted, a great deal of work has been done on the nutritional requirements of poultry in the various stages of their life, in an attempt to solve the many questions which mean so much in the efficient management of a flock. What, for instance, is the best amount of protein to feed at different stages of growth and production? What amounts of mineral should be fed to chicks, to pullets and to layers, in what ratio should they be included and from what sources should they be taken? What are the requirements of the chick and of the hen for the various vitamins, and what feeds supply these in greatest abundance, and with the greatest economy and convenience in feeding? These are similar questions from a large part of the research program in poultry nutrition and the answers as they are found are quickly translated to practical condition, so that reliable feeding standards may eventually be established.
Another phase of the work, which has received a good deal of attention, is the effect of nutrition on the quality of the product, e.g., on the strength of the egg-shell, the colour of the yolk, the consistency of the albumen and the food value of the egg. For instance, the quality as well as the quantity of protein fed to laying hens has been shown to have a definite effect on the amount of protein in the egg, but little or no influence on the chemical composition of the egg proteins. The vitamin content of the feed, however, is definitely reflected in the product, and has a strong influence on the strength and vitality of the embryo. Such foodstuffs as mild, cod liver oil and alfalfa, have been shown to be highly efficient in improving hatchability, and are now recommended as important elements in rations for the breeding flock.
Another feature of recent investigational work in poultry nutrition has been the study of the relation of diet to disease. Many ills, such as various types of leg weakness in chicks, crooked breastbones, some forms of paralysis and some types of respiratory diseases, can now be traced to defects or deficiencies in the ration. Furthermore, it is becoming more and more evident that while active disease does exact a heavy tool of our flocks, the most serious losses are traceable ultimately to low efficiency from malnutrition. Poor nutrition over an extended period may be responsible for retarded growth, and low vitality, and as a consequence, for low production ill-health and low hatchability of the eggs. It may also produce alterations in the chemical composition of the blood and other body fluids, which will lead to a lowering of the defense mechanism against bacterial invasion. Recently there has been submitted some evidence that nutrition may have an effect on immunity, that is, on the power of the antibodies and the white blood cells to combat disease organism. If this should prove to be the case, the composition of thee diet will become an even more important factor in good management that it is conserved today.
Discoveries in the field of nutrition are thus materially affecting the trend of poultry keeping, which is now definitely towards larger flock units, confined to small areas where close control is possible and production costs can be reduced. Emphasis, however, is laid on the importance of sanitation and on complete balance in the ration, to compensate for the natural agencies, which cannot be utilized. The poultry man himself must also advance with the times. He must not only become familiar with the fundamental considerations involved in the practice recommended and keep up-to-date with the newest and best that science has to offer, but he must adopt sound business policies in the management of his enterprise. Only by such means will he be enabled to avoid the pitfalls and embarrassment, which surrounded the industry at the present time, and to maintain the high efficiency which is essential to any profitable undertaking.
A formula for a milk-derivative whey-powder, which is likely to prove of considerable importance in disease resistance and health maintenance among poultry, particularly in the control of coccidiosis among chickens, has been discovered by F.H.Clickner, professor of Nutritional Research of Rutgers University and research chemist of Kraft-Phoenix Cheese Corporation. The provision of mineral salts in correct balance in the diet is as important to the health of poultry as to human beings, Professor Clickner has found in his experiments.
Professor Clickner’s extensive research in poultry feeding began in 1925 when a brood of 1200 baby chicks at the Green Brock Poultry Farm, a New Jersey State certified farm, were started on a mash feed containing 15 per cent of the whey-powder developed in the Kraft laboratories. The entire brood was permitted to run on soil heavily infected with coccidiosis organisms. The result was that 93 per cent of the fowls were raised to the age of 10 weeks – the danger period – without the signs of coccidiosis.
Eliminated in Ten Days
First experiment with the use of the milk-whey remedy fro coccidiosis were conducted by Professor Clickner at the Smith Brothers Farm near Vineland. The maximum time required to arrest and eliminate acute coccidiosis infections was 10 days. These cases were treated with a mash, using 25 to 30 per cent of the whey-powder.
Coccidiosis and leg-weakness, the two chief diseases among poultry, were found to yield with miraculous speed to the use of whey-powder. In all cases under experiment, not only was the disease situation completely controlled by the use of whey-powder, but uniformly superior chicks resulted; chicken with a high degree of pigmentation, yellow shanks and beaks.
The major ingredient of this new compound is milk-lactose or milk-sugar, constituting 75 per cent of the product. Heretofore 50 per cent has been considered the maximum milk-sugar content of milk derivations which could be obtained.
The function of milk-sugar is to produce sufficient lactic-acid in the intestine of the bird to combat the bacteria. After a few days of feeding milk-sugar, sufficient acidity is produced in the ceca of the bird to destroy the parasite of the coccidiosis, Professor Clickner’s report shows.
Several months ago I wrote of the very high egg yields that have been obtained at the experiment station in Washington State on grain rations of corn, oats and wheat in different combinations with nothing to drink but milk.
No mash was fed. The grains were balanced by the milk. From the number of inquiries received I know the readers are much interested in this subject of simple rations.
And now the Massachusetts Agricultural College has reported experiments which, if further substantiated, will save farmers and poultrymen a lot of time, labor and worry.
The Massachusetts results jar loose another of the fine little theories we have all had roosting on the back porch of our brains for as long as anyone can remember anything about chicken: to wit, that we had to feed our scratch feeds in the litter because if we left it available at all times the birds would overeat, become too fat, quit laying and die of fatty heart.
The experimenters fed a mash of corn meal, wheat bran, middlings, oat products, meat scraps, fish meal, alfalfa meal, bone meal and red milk and kept salt available in hoppers at all times. They fed corn and oats whole in hoppers also, and not in the litters.
The flock so fed gave the highest average egg production of any flock kept on the college farm up to that time. The average egg production was 205 eggs per bird.
The highest winter egg production ever obtained from the experimental flocks was during these same experiments with both grain and mash hopper-fed.
The birds ate more grain than mash, the percentages varying with the season. The smallest percentage of grain was consumed in the fall and winter, the largest during the spring and summer. As would naturally be expected, they ate more corn than oats.
Further experiments must be tried before this almost revolutionary practice of hopper feeding all grain from the hopper can be generally accepted as the right thing to do. But these experiments certainly do open up that possibility.
Think of the labor-saving in not having to go to the poultry house at least twice daily at stated times to litter-feed the grain. Think of not having to leave some very interesting or valuable meeting to rush home to feed grain at a certain hour in the evening – just fill up the hoppers before you leave and nothing to worry about; no worry as to whether you are feeding just the right amount of grain to keep the egg production up and the body flesh right.
It seems as if in our methods of feeding at least we are coming more and more to rely on the judgement of the chickens and less on ourselves. And since it is the chickens’ appetites and stomachs and not ours that have to be satisfied, maybe it isn’t so far wrong after all.
It is a hard blow to our vanity, though, after all these years, to find out that the chicken (the one that doesn’t know enough to stay on its own side of the road when the cars go by) may know more about feeding than we do. But then this same ignorant chicken apparently knew she should be in the sunshine to maintain her health long before we did. And before it is all settled she may teach us many more lessons.
As a result of scientific experiments in the cross breeding of poultry, conducted some years ago at Cambridge University and latterly by hundreds of poultry-keepers chiefly in Great Britain, it has been ascertained that certain definite crosses can be made which will produce sex linked chicks; that is, chicks that can be quite clearly distinguished as cockerels or pullets at birth.
The possible crosses are usually divided into three classes as follows: (a) Self-coloured cocks crossed with barred hens. (b) Dark shanked cocks mated to light shanked hens, and (c) which is generally conceded to be the best and clearest form of sex-linked cross consists of mating what are termed “gold” cocks, which includes all breeds in which the ground colour of the chick’s down is some shade of buff of golden brown, such as Brown Leghorn, Rhode Island Red, Red Sussex Buff Orpington, etc. These gold cocks are mated to what are termed “silver” hens, which are not necessarily pure white hens, but include Black Plymouth Rock, Silver Wyandotte, Light Sussex and any breed in which the down of the chicks has a large percentage of cream colouring, not white.
Some Breeds Unsuited
There are many complications attached to sex-linked cross breeding, and whilst the choice of matings is very numerous, it should be realized that some breeds are totally unsuited and others doubtful for the production of sex-linked chickens.
Those who wish to go more deeply into the matter may be referred to Professor Punnett’s book “Heredity in Poultry” which gives a full list of all known sex-linked crosses and their results. This book is published by Macmillan & Co.
Only a few of the possible sex-linked crosses can be considered from a utility point of view, and to the breeder who is not biased in favour of any breed, the following which have been found to give excellent results can be recommended. (1) White or Black Leghorn cock mated to barred Rock hens. (2) Light Sussex cock mated to Barred Rock hens. (3) A Minorca cock mated to Barred Rock hens.
All of the above come under the class (a) and chicks from such matings are distinguishable by the cockerel chicks having a white patch on top of the head when hatched, and the pullet chicks having an absolutely black head at birth.
Generally speaking Class (B), the crossing of Dark Shanked Cocks with Light Shanked hens is not to be recommended because the distinction in the colour of the shanks of day old chicks is so fine as to need considerable experience before any certainty of accuracy can be depended upon. At the same time, the possibilities of this class mating cannot be overlooked since it is the only possible means of utilizing for six-linkage purposes the ever popular White Leghorn hen. White Leghorn hens mated to dark shanked cocks such as Hamburg, Langshan, Black Rock, Black Minorea, Black Orpington, Australorp, would produce day-old cockerels with light or yellow shanks, and day old pullets with dark shanks. In this connection, it is well to mention that although the White Wyandotte has a “silver” origin, it is not always to be depended upon for crossing with the “gold” cocks from sex-linkage, because White Leghorn blood has been introduced into the White Wyandotte breed by some breeders in the past to improve egg production, and there is always the possibility that the presence of a few Wyandottes carrying White Leghorn blood would vitiate the results from the whole flock, and since it would be almost impossible to detect the aberrant birds, it is advisable in order to obtain a sex-linked cross to make use of the dark shanked cocks in the same way as with the White Leghorn.
The La Bresse Cock which has dark shanks has been found to give excellent results mated to the White Leghorn or White Wyandotte hen.
In Class (c) the Rhode Island Red cock mated to the Light Sussex hen, the Brown Leghorn cock mated to Light Sussex hen, and the Red Sussex hen all produce day old cockerels that are silver or white coloured, and day old pullets that are golden or buff coloured.
Cross Only High Grade Stock
It should be thoroughly understood that these crosses must be made as written, for if the reverse mating, such as Light Sussex cock mated to Rhode Island hens were made, the chicks would be in no way sex-linked, and the sexes would be indistinguishable. Again in crossing these breeds for utility purposes, it is imperative that absolutely first class sock of high egg producing qualities on both sides be used.
The advantages to be gained from sex-linked breeding are self-evident. In the first place, the breeder can offer day old pullets for sale to the commercial egg farmer, who will be saved the trouble of brooding cockerels which do not interest him.
In England today, the demand for day-old sex-linked pullets is greater than the supply. It is safe to say that the average commercial egg farmer would be glad to pay double the price for guaranteed day-old pullets that he now pays for ordinary day old chicks. The breeder could then either sell the day old cockerels at a low price, or brood them in the new electric battery brooders, raising them from broilers.
Those who have had experience of the scientific cross breeding are unanimous in stating that hatchability is at least ten per cent better, mortality in chicks is at least ten per cent lower, growth of both sexes is much more rapid, and maturity of pullets is two to six weeks earlier, also mortality in adult stock is reduced to a minimum, and egg production is increased by at least ten per cent over what could be reasonably expected from pure progeny by either of the pure breds originally used in the cross mating.
A Successful Experiment
The following excerpt of a report on experiments conducted by “Poultry” England, should prove of interest to illustrate the value of sex-linked cross breeding – “We have tried several kinds of fowl for sex-linked crosses, but so far the most satisfactory result has been from Light Sussex hens mated to a Brown Leghorn cockerel. These birds had to pass the expert for standard, but were of no particular laying strain. They were of good weight and excellent vitality. The sex of the chicks was decidedly easy to distinguish since as day olds the cockerels were silvery white, and the pullets red brown. The cockerels realized top prices as broilers. Seventy-five per cent of the pullets started laying at eighteen weeks old, and the remainder quickly followed. At this time (18 weeks old) the pullets weighed 4-1/2 pounds each. Their eggs were saleable as extras from the commencement; and at six months of age the birds weighed 5-1/2 pounds each and were producing 2-1/2 ox eggs. In body formation they resembled heavy Leghorns, were uniform in colour having a buff body colour with black striped neck hackles, and made an attractive looking flock”.
At the National Laying Contest, England 1927-28, 133 cross bred pullets entered in a special first cross bred section, mostly by backyard or amateur poultry-keepers, and not by professional breeders put up an average of 206 eggs per bird in 48 weeks, which was ten eggs per bird more than the average for the whole contest. Not one cross bred pullet died or was sick.
Heavier Egg Production
During the first two winter months of the present English National contest, 156 cross bred pullets averaged 25.01 eggs per bird per month, which was considerably higher than the average for any pure bred bird.
A comparison between the above official average records and the average production obtained from pure bred flocks either in R.O.P or any Canadian Laying Contest will show that these cross bred pullets put up altogether heavier egg production than an official Canadian flock of pure breds.
The only argument against sex-linked cross breds is that they are not suitable for reproduction, which the writer ventures to suggest is sheer theoretical bunk based on the fact that cross breeding in the past has been haphazard in the hands of absolutely inexperienced poultry keepers. The theorists who put up this argument against cross breeding appear to have overlooked the fact that the very best of our modern pure breds originate at a comparatively recent date from a long series of cross breeding. The original Rhode Island Red, Orpington, Sussex and Barneveld are a result of many generations of cross breeding cross breds.
Even assuming that these cross bred pullets are unsuitable for breeding purposes, there is nothing lost, since of the vast number of pure bred chicks produced annually only a very small percentage are either intended or suitable for future breeders.
The Modern Method
The process of reproduction of pure bred stock today is something like this. The poultry breeder mates up two or three pens from which he produces his own future breeding stock, and he also mates one or more large flock pens from which he produces commercial chicks to be sold by the thousands to egg farmers all over the Continent, and which are destined to produce eggs from human consumption only, and not for hatching. The destiny of a chick for breeding is entirely different to that of a chick for egg production, and it should receive different and better treatment thoroughly its life.
What is to prevent a breeder from keeping two or three special pedigree pens of two different pure breds from which he would produce a certain number of pure bred pullets according to the size of his business. These pullets would be trapnested and the very best of them selected for the reproduction of more pure bred stock. The balance of the high egg record hens would be flock mated to high egg record pedigreed cockerels of the other pure bred, and from this pen day old sex-linked pullets could be produced from commercial egg production.
Poultry owners have lately been experiencing a new disease among their poultry; it is observed mostly during the winter months but has occurred in some sections in late summer and early fall, if the weather has been dry and vegetation dry and fibrous. The strange thing about this disease is the fact that while it has the appearance of roup it is different than any other outbreak any of these poultry keepers have experienced. Many of them are at a loss to understand it.
This condition is spoken of as nutritional roup, but by others as nutritional disease, but the more correct term would likely be nutritional opthalmia of poultry; this is a disease due to improper feeding or nutrition; it should be classed with deficiency diseases, for that is what it is. By deficiency diseases we mean those diseases that are the result of the bird not getting all of the nutrients in sufficient amounts from its feed. The usual deficiencies are those of vitamins and minerals or both; it would be difficult if not impossible to tell which is most likely deficient as both of them are found quite closely associated in many of the common feeds used for poultry
Poultry owners will wonder why we have not bothered with this disease. In times past; this is a disease that is the result of greater domestication of our poultry; with improvement in production and housing, close confinement for heavy production and close breeding poultry are removed further from their natural habits, with the result that we have new problems of feeding or nutrition to contend with; this is one of them; problems that confront us now will possibly pass along and others appear to baffle us during the next decade. The poultry keepers’ problems are constantly changing because his methods of handling his poultry are constantly changing and because the habits and work that his poultry do are also changing.
The use of a large number of products of the modern milling practice has brought new problems for the nutrition expert; as still greater improvements are made in milling practices other problems will be solved; when poultry was fed on whole grains and seeds or upon feeds made from them there was not the same class of diseases that we have now. Few if any of these by-products that are so largely used in poultry feeds carry all of the commonly needed nutrients in sufficient amounts to enable one to make a balanced ration with them. The continuous cropping of the soil for many years without the return of ample minerals in the form of fertilizer or lime, or both, has deprived the soil of the usual amount of minerals with the result that the crops produced thereon do not have the usual amount of minerals and when used in poultry feeds result in improper nutrition.
The causative agent of nutritional disease is one of the vitamins. While vitamins have been discovered for several years we do not know much about them other than where they are found and what they do. The vitamins whose absence from the ration causes this condition is know as vitamin A (fat soluble A); it is found in such feeds as milk, yellow corn, green things, such as cabbage and chard, in egg yolks, in clover and alfalfa, etc. With a carefully balanced ration it is not difficult to supply this vitamin in sufficient amounts. During the winter months when green feed is difficult to obtain or during the late summer or early fall when it is dry and fibrous is when you can expect to have this disease in your flock. Since it is most often found during the winter months it is often mistaken for roup.
Nutritional disease makes its appearance in the flock rather slowly: the birds do not take down with it as rapidly as they do with roup and neither do they show so many signs of having a cold as they do with roup. The eyes swell and there is a white discharge accumulates in the eye, but this can be wiped out rather easily. The discharge from roup is brownish and clings to the eye; it can only be removed with difficulty.
The post-mortem shows the greatest difference between these two diseases. Upon opening the gullet of the bird affected with nutritional disease you will find a large number of small nodules which may be no larger than a millet seed; they are not raw on the surface or covered with a membrane; you will find a brownish membrane covering these patches in roup; the heart may be speckled with white as are also the liver and kidneys in nutritional disease; they look as though they have been sprinkled with flour; you will not find this with roup; the kidneys are greatly enlarged in the bird with nutritional disease; there is a characteristic odor affecting ropy birds that is not present in those that have nutritional disease. The birds with nutritional disease very frequently have a diarrhea in which there is considerable white material; this is not found associated with roup.
The characteristic things about roup are the brownish discharge of the eye which is clinging and cannot be easily removed; the characteristic odor and the patches in the gullet covered by a brownish membrane; also the rapidity with which it travels through the flock and its early association with a cold. It is necessary to differentiate between these two diseases if possible for the line of treatment that would satisfactory for nutritional disease would not be at all suitable for roup. The fact remains however that in instances the both type may be found in the same flock at the same time; this would not be expected very often but it is a possibility.
Both the curative and preventative measures for nutritional disease are one of supplying the proper feeds; with such feeds as yellow corn, middling, milk and green stuff there is little need to worry; if this is not sufficient then other green things such as spinach, if it is available, or clover or alfalfa hay may be used, together with cod liver oil; whole milk should be given when this trouble appears. Medicinal treatment would be of no help for this condition.
The handling of roup is quite another thing. It is a matter of sanitation and hygiene. The building must be cleaned and disinfected at once and should be kept dry; there should be no draughts but as much sunlight as possible. The badly infected birds should be destroyed and burned. For the others, 20 to 30 grains of potassium permanganate should be placed in each gallon of drinking water and this should be placed in crockery or glass containers (this can be purchased at most drug stores in 5 grain tablets); this should be kept before the birds at all times; 1 lb. of epsom salts dissolved in water and mixed with enough feed for 100 hens should be given once or twice each week, as needed. Keep the birds in the sunlight as much as possible. Over crowding is a beginning for roup in many instances.
THE GOLDEN RULE IN EGGS
An egg for hatching is an uncertain proposition, and it is, therefore, of utmost importance that we deal only with people in whom we can place utmost confidence. At the same time, nothing really complicated is involved in the ethics of buying and selling eggs for hatching.
On the seller’s part the eggs sent out should be fresh laid, nicely packed and well fertilized and from the exact mattings represented. In case of poor results from improper handling or chilling of the eggs in transit, the shipper is certainly ding his part when he duplicates the order at half price or replaces free all eggs that test out clear on the tenth day.
The buyer of eggs should not expect every egg to hatch, but should be satisfied with seven or eight chicks from fifteen eggs. In addition to that, he has a right to expect good quality in the majority of the chicks, and that is more important than quantity. Sometimes, it is true; every egg hatches even after being shipped long distances; but if such results were common the price per setting would of necessity have to be raised. The “law of compensation” must necessarily apply. It often occurs that one good chick on maturity is worth more than the price paid for the entire setting of eggs.
These are facts as we see them after considerable experience on both sides of the question. The buyer often feels that he did not get full value for his money, and it is also true that the seller is often imposed upon and blamed for conditions entirely beyond his control. If both parties will just use the Golden Rule everything will usually end quite satisfactorily.
CAREFUL AND CONSTANT ATTENTION
Those who regard the production of eggs for market as a straight and easy road to wealth should remember the fact that the flock of hens which will produce eggs at a profit all the year round must receive careful, constant and skillful attention, early and late, week days and Sundays, for the full 365 days of the year.
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