Jun. 6, 2013 - As livestock became more important to the rural economy in the late 1800s and early 1900s, the Ontario Veterinary College (OVC) evolved to service the needs of both animals and people.
"The changes that happened at OVC, particularly between the two world wars, laid the groundwork for what we are able to do now," Dr. Elizabeth Stone told an interested group of history buffs at a Rural History Roundtable lecture recently. As the 10th Dean of the OVC, Stone delved into the history of the institution to put its evolution in perspective as the college celebrates its 150th anniversary.
An 1830 census shows that there were 177,722 farm animals in Ontario: 80,000 dairy cattle, 32,000 other cattle, 33,000 work oxen, 30,500 horses and an assortment of other livestock. While this may not seem large, consider that there were only 213,000 people in Ontario (then Upper Canada) by comparison. By 1851, there were five million animals, and by 1870 livestock products were providing 60 per cent of the agricultural output of Ontario, surpassing wheat.
One-third of the animal products were dairy related, such as cheese, and by the 1880s there were three dairy associations in Ontario.
"Cattle and dairy were central to the agricultural economy," said Stone.
The Human Factor
Human populations were growing too. In 1865 there were 660,000 urban residents and 1.3 million living in rural areas. By 1909, that trend turned, with immigration largely responsible for an increase in urban dwellers to 1.24 million, while the rural population dropped to 1.05 million. This meant that farmers needed to not only provide for people in urban areas, but for an export market as well.
Livestock were considered the key to prosperity at that time and there was a need for veterinarians to care for them. Thus, a delegation was sent to Edinburgh to recruit 23-year-old Prof. Andrew Smith. He founded Upper Canada College on Temperance Street in Toronto, erected the buildings with his own funds and taught anatomy and disease courses. Prof. George Buckland joined him to teach management and husbandry.
The school was successful even though it was accused of having low admission standards and being "not too rigorous." In 1895, a candidate for acceptance needed only to present evidence of a "good common school education." If no certificate was available, an entrance exam was required for reading, writing and spelling – but if a candidate did not pass he could still start the two-year program.
In 1908, the Ontario Ministry of Agriculture took over the veterinary program, lengthening it from two to three years after high school, and to four by 1918. This was spearheaded by E.A. Grange, who was second principal of the OVC from 1908 to 1918.
Moving to Guelph
By 1918, with C.D. McGilvray as the third OVC principal, interest grew in moving the college "a day's horse ride away" from Toronto to Guelph, but a new building had just been completed on University Avenue in Toronto. At that time, horses were replacing oxen as beasts of burden, light horses were being replaced by motor vehicles for transportation and cattle numbers were increasing exponentially.
The move was met with "weeping and gnashing of teeth," said Stone. In fact, several faculty members refused to move and the University of Toronto resources were left behind. However, by the time of the grand opening in 1922, McGilvray pronounced: "a catastrophe [had] not occurred."
Students were told that the close proximity to the Ontario Agricultural College would fulfil the mandate of the veterinary profession to serve not only the health and management of livestock animals, but also public health and food safety.
Once in Guelph, courses became hands-on. At farms where Stone Road Mall now stands, students worked with cattle, sheep, swine and horses. Milk hygiene courses also expanded, as well as courses in poultry disease and husbandry.
By the 1930s, courses concerning the diseases of fur-bearing animals such as mink and foxes were quickly attracting students. While dogs and cats were always part of the curriculum, they were done almost on the side, said Stone. It wasn't until the 1950s that a small animal clinic was added to the OVC building.
"Which animals are valued continues to change the veterinary profession," said Stone.
Overall, OVC research and extension work provided both a practical and a valuable service to the province in the 1930s, especially in regards to disease research. And by the end of the depression, while Brucellosis testing was still being developed, results were showing that a vaccination program was working.
In 1931, a prevalence of nutritional issues was appearing in the journals, such as compensating for phosphorus deficiencies that were associated with a lack of variety of winter-feed. This was research that farmers could directly implement, said Stone, and that became the driving force behind faculty research. Since then, the OVC has been leading the way in animal research and veterinary medicine.
A New Book
As well, a new book has been released, entitled Milestones: 150 Years of the Ontario Veterinary College includes photos and details from the opening of the first veterinary college in Canada and the United States to today’s OVC. The book will be available for purchase during Alumni Weekend, and later on Amazon.com.
Co-authors Lisa Cox, a PhD history candidate, and OVC associate dean Peter Conlon dug through the University archives and interviewed former faculty and donors to find the 150 most interesting stories.
“I think the biggest challenge when creating a book like this is to determine the balance between historical and modern,” said Cox. “We’re talking about a school that was so critical to the professionalization of veterinary medicine, so there are many historical achievements. But we also have some great modern successes, so a significant issue is finding ways to integrate both into the book.”
The new book contains many more photos than a historical volume published for the college's centennial. Some of Cox’s favourite pictures depict the Canadian Army Veterinary Corps serving Canadian and British troops during the First World War. A total of 309 OVC students, faculty and graduates served in the war, with some dying in battle.
“The stories were chosen to try to demonstrate unique aspects of OVC’s history and how that history is interwoven with the history of Ontario and Canada over 150 years,” he said. “I’m proud that we were able to recognize so many people’s contribution to the success of the college and all of veterinary medicine. Some of these people are well-known, but many are not; however, each one has contributed in various ways to create our history. Without every one of them, who knows what OVC would look like today?”
Hens are going to become more feminine. Science applied to feeding of poultry is going to make them that way. Main reason why every chicken farmer will love these hens with the extra feminine touch is that they will produce 20 percent more eggs without added feed cost. But this isn't all – pullets will attain peak egg production three weeks ahead of what is now considered normal.
The period of maximum laying is lengthened from 30 to 90 days, according to indications at the end of a full year's experiments. And by stimulation of feminine characteristics in the old hen that has almost ceased to lay at all, she can be restored to within 10 percent of egg production during her pullet year.
The poultryman with this magic control of what goes on in his henhouse will be enabled to hold early-hatched birds over periods of better egg prices as profitable laying members of this flock. He can increase the paying productive period of each of his birds from six to eight months – how much longer is not definitely known. The period of moult in his chickens can be shortened to an average of 31 days per bird, instead of 60 to 90-day moult normally experienced, maintaining 60 percent production from the birds even during moulting.
Key to the almost unbelievably advantageous state of affairs is a hormone. Scientists have known, of course, that hormones account for manifestations of dominant sex traits. They had proved this, even in chickens, by various laboratory methods, including injections, and to varying degrees of success – or its lack. It was conceded generally to be so costly that use of hormone materials in commercial poultry production would be impossible.
Topping more than 35 years' research by other scientists with 12 years' intensive work of his own, an Italian biologist developed feed materials rich in hormones derived from natural sources through special compounding and methods of processing. The discoveries of Professor Antonia Morosoni, formerly assistant to the chief at the Legal Medicinal Institute, University of Palermo, Sicily, were acclaimed widely by various European universities, ministries of agriculture, and numerous scientific organizations.
Satisfying preliminary requirements of the United States Department of Agriculture with European tests of his research, Professor Morosini arranged for limited production of his hormone feeds by a feed company at Lakeland, Fla.
Since a revolutionary type of feed is basis for such astounding claims for improvements in poultry production, it might be said appropriately that "proof of the pudding is in the eating." That's exactly what commercial flocks at Benton's Poultry Farm, on Route 8, near Tampa, have been doing since June 20, 1949.
In tests, under actual commercial poultry farming conditions, that are rounding out a full year this month, practical poultry husbandry has been under the management of Howard C. Benton, Scientific collaborator in tests of the hormone poultry feeds is Dr. C. D. Gordon, former USDA poultry co-ordinator, Washington, D.C., conductor of research in poultry genetics at Auburn University, and recently director for four years at Chinsegut Hill federal experiment station near Brooksville.
First test at Benton's farm involved a pen of 100 pullets three weeks old. To establish a control, the pen was replicated by another with an equal number of birds selected on a family basis. Management involving vaccination, housing, sanitation, etc., was identical for each pen. Feed for both pens was of comparable quality, and feeding was in strict accordance with manufacturers' directions. Only difference is that feed for birds in the test pen contained hormones.
At five months of age, each individual bird in both pens was checked for weight. Birds on hormone feed test averaged more than eight ounces heavier than birds of the check or control pen. The test birds showed more apparent female characteristics in their development and laid their first egg three weeks ahead of the controls. Eggs produced by hormone-fed birds were consistently heavier than those produced by the other birds even six months after laying started – which was one year after the experiment began.
A pen of 100 pedigreed New Hampshires between five and six months old was replicated to establish control for the second test. Six months after the test began; chickens on hormone feed were continuing to lay 20 percent more eggs than the control birds on standard feed. Eggs produced by hormone-fed chickens were larger by 1 to 1 ½ oz. per dozen than eggs laid by the control birds on standard feed. This test is being continued indefinitely to determine how long hormones feed will prove effective and what its ultimate effect will be both on the birds and their productivity.
Chickens in a third test were from a group of 26 pedigreed New Hampshires that had been entered in the Florida National Egg Laying Contest at Chipley, Fla. During 50 weeks of the contest, these hens laid 5,721 eggs. But during the last month of the contest they laid only 179 eggs; and by the time they were returned to the farm, egg production was negligible. The hens were put n hormone feed for 30 days. In the next month, November, these hens laid 292 eggs. This is a sharp contrast to normal conditions under which contest hens, commercially worn out and in forced moult due to shock from change and travel, were practically out of production. During January, after being on the hormone feed 90 days, this group of hens laid 357 eggs.
Summarising the records involving hens in this test, 26 birds laid an average of 219.2 eggs per bird during 350 days. Following this performance, 21 of the same birds averaged 97.5 eggs each in 180 days. What this means is that hens normally useless and out of production have been able to maintain a 53.9 percent production on hormone feed, although they were seven months older than at the end of the egg-laying contest at Chipley and a year older than at their peak of production reached during the contest.
As of May 1, these hens had been laying 18 months. This apparently proves that hormone feeding enables the poultryman to keep old hens – even when they are 27 months old – as profitable producers in the laying flock. Lifetime production of the birds reported in this test is 339.7 eggs per bird average. This is 52.5 percent production – and the poultryman whose flock does that well makes money. This test also is being continued indefinitely.
Although Florida investigators wish to make no specific claims at this time, it seems as though knowing how to develop feminine hens places them nearer to solution of the age-old mystery of sex predetermination. European research indicates that chickens fed hormone feeds and selected for families showing high feminine reaction to hormone stimuli can be bred to produce fertile eggs that will hatch up to 80 percent pullets – instead of the normal 48 percent.
The theory applied to limited experiments in Florida so far has shown maximum of 60 percent pullets in one hatch, with an average of better than 52 percent. Practical interpretation of this is that some day poultrymen may have a new strain of baby chicks that are feminine to the last feather, because mamma and grandma ate hormone feed; and they'll grow into super egg producers. – "Poultry Digest."
Ontario lost a large number of birds last summer to heat, Harry Huffman, an agricultural engineer who specializes in ventilation, told about 60 broiler producers at a seminar in Holmesville, Ont. sponsored by the Ontario Ministry of Agriculture and Food.
Southern Ontario had 46 days with temperatures over 30 degrees C, 13 days over 34 degrees and eight days over 35 degrees.
While there was little precipitation last summer there were a number of days with very high humidity, which increases the heat stress, he said.
“Heat stress is most severe when high temperatures are coupled with high humidity,” he said.
Environment Canada has developed a formula that combines the two factors to create a Humidex reading. These readings reflect the comfort level for people.
While no Humidex reading has been done for livestock, Huffman said, it’s safe to assume that animals will have somewhat similar degrees of discomfort with heat stress.
Humidex comfort levels on the chart are as follows: 29 or lower, no discomfort; 30 to 39, some discomfort; 40 to 45, great discomfort, avoid exertion; above 45, dangerous; and above 54, imminent heat stroke.
As long as the humidex is below 54, growers can do a number of things to reduce the severity of heat stress. Above that level, “it is quite likely some bird losses will occur regardless of housing management,” he said.
The first thing is not to overcrowd summer flocks.
Second, acclimatize the birds to possible heat stress at four weeks of age by allowing the barn temperature to rise for several hours. Research shows that short bouts of heat stress will help the birds survive future heat stress periods.
Third, increase the light level in the pen prior to operating large-diameter fans or opening tunnel ventilation doors. This will reduce the fear reaction and subsequent flight from the bright areas. This type of flight reaction has caused piling near the centre of the barn and suffocation.
Fourth, exhaust sufficient air in hot weather. Try to keep the barn within two degrees of the outside temperature and aim for a complete air change every minute.
Fifth, ensure that the air inlet has sufficient capacity to handle the fresh airflow. There should be at least 1.5 square feet of inlet opening for each 1,000 CFM of fan capacity and some insurance companies insist on two square feet for heat prostration coverage.
Sixth, verify proper air intake velocity with a static pressure gauge. In order to have good air movement it is important to have lower static pressure in summer. The usual range for summer, he said, is .03 to .06 inches while in cold weather the range will be .05 to .08 inches static pressure.
Seventh, if the static pressure is too high increase the fresh air openings. Ideally, this will be done by increasing the air inlet opening of the addition of more air inlets to enhance the airflow over the birds. Doors can be used, he advised, if they are only opened to the extent necessary to bring the static pressure down to the correct range. Opening too many doors will eliminate the vacuum and airflow will be less than required everywhere except directly in front of the openings.
Eighth, make sure the air is moving across the barn at bird level. This air movement is required to remove the heat from the bird as quickly as possible. Moving air at a reasonable speed around the birds’ heads and necks has the potential to reduce the perceived temperature by one to three degrees Celsius.
There are a number of ways to increase air movement at bird level, he said.
These include: a deflector board for a typical side air inlet; a new double side air inlet system; a second air inlet lower on the side wall; a second air inlet on the opposite side of the barn; tunnel ventilation; tunnel ventilation baffles to increase air speed; and internal air circulation fans.
Ninth, make sure the birds get plenty of cool water. Water consumption should double during hot weather.
Tenth, slowly walk the birds during periods of heat stress. This promotes air movement and releases the heat trapped under the birds, Huffman said. It also encourages the birds to move to the drinkers and allows you to more closely monitor the birds. However any bird activity generates more body heat and can increase heat stress. Therefore, this walking exercise may be best if done in the morning when it is usually cooler.
Eleventh, ensure that the attic is properly insulated and ventilated.
Twelve, any colour other than white will absorb significant solar heat. There can be significant attic heat reduction if the roof is painted white. In addition, there are now ceramic paints or coatings available, in a variety of colours that will reduce solar heating.
Thirteenth, if possible have the air inlet on the shady side of the building.
Fourteenth, talk to your feed company representative and veterinarian about feed withdrawal practices during periods of heat stress.
Fifteen, consider some form of evaporative cooling. Adding water vapour to the air is an excellent way to bring down air temperature, he said. Depending on the humidity levels evaporative cooling can reduce air temperatures anywhere from one to six degrees because the water vapour absorbs heat.
The impact can be dramatic. For example (referring to the Humidex chart), it can be seen that if one could bring the temperature down from 34 degrees to 30 degrees the Humidex would be in the safe zone even if the humidity rose from 80 to 85 per cent. Even at 90 per cent humidity the Humidex is 45.6 compared with 52 at 80 per cent humidity.
In summary, Huffman said there are a number of things that can be done to help your birds survive the heat, but they require planning and may involve some spending.
“Therefore, give the various options some thought over the winter and have your improvements in place prior to next summer’s heat wave,” he said.
To determine the cost-benefit of a biosecurity system, one needs to juggle two types of information: facts about the economics associated with the type of production and the costs of implementing a biosecurity system; and estimates of the relative risk and cost of disease.
Many relatively inexpensive biosecurity measures may generate substantial benefits. Most are designed to control people access to the farm and to improve sanitation. However, these are dependent on compliance. The challenge is to convince all poultry personnel of the impact of their actions on the risk of breaking with an infectious disease. Education and communication are key factors in determining people’s perception of disease risks and, consequently, their assessment of the potential benefits of a biosecurity system.
In high density areas, a regional perspective is essential to the design of a biosecurity system, mainly in the face of an epidemic. Hence, the challenge for today’s poultry industry is to determine the cost-benefit in partnership with regional competitors.
Infectious diseases have always been a limiting factor in commercial poultry production. The scientific community has responded fairly successfully by producing effective vaccines for conditions such as Marek’s disease, hemorrhagic enteritis, Newcastle, infectious bronchitis, etc. However, even when vaccines exist, diseases remain costly; in particular in a global market economy where they can be used as trade barriers.
In the United States, the vertical integration of the industry has produced large efficient multi-site complexes designed to enhance productivity and reduce production costs. This model has been very successful economically. However, over the past few years, it has been challenged by emerging and reemerging infectious diseases. For example, several outbreaks of infectious laryngotracheitis and of mycoplasmosis have been reported. Poult enteritis mortality syndrome (PEMS) has had a devastating effect on the turkey industry in the South East United States. Turkey coronavirus enteritis (TCE) is still very much prevalent in the eastern part of North Carolina. In the northeast and the south, many industry people and health officials have expressed concerns over the presence of Avian Influenza in live bird markets.
These public health and production concerns need to be addressed. Biosecurity should certainly be the corner- stone of any long-term response to disease aggression. However, given the concentration of farms in certain areas, such concerns cannot be addressed solely by on-farm biosecurity.
A regional perspective is needed, and should be part of a biosecurity system. How do you determine the cost-benefit of such a system? This is not an easy question to answer. Preventing the occurrence of a given disease on a given farm cannot be, without a doubt, attributed to a specific set of biosecurity rules. In other words, you do not know for sure whether your biosecurity system is truly effective or whether the flocks on your farm have simply not been at risk. It is also true that the most stringent biosecurity system does not offer an absolute protection against diseases. Rossigneux (1998) suggests that the word biosecurity is indeed misleading because security implies the absence of danger (i.e., infection), which is probably never achieved under field conditions. So, to answer this question, one needs to juggle with two types of information: facts about the economics associated with the type of production and the costs of implementing a biosecurity system; and estimates of the relative risk and cost of disease.
Economic models developed to assess the value of biosecurity systems suggest that prevention of disease in the end is always less expensive than treatment (Morris, 1995). Gifford et al. (1987), working on a model for broiler breeders, confirmed “that expenditure on protective measures can be justified by both the risk of introducing a disease and the magnitude of losses that may occur following infection”. On a broiler breeder farm, the benefit-cost ratio of biosecurity is at least three for a farm considered at a 30% risk of being infected by an agent causing a severe disease. In the case of the most pathogenic conditions, they found that investment in biosecurity was justified even with a 0.01 probability of outbreak. However, the challenge in assessing the cost-benefit of a specific biosecurity measure is to contrast the resulting investment with other potential ventures. For example, adding an automatic gate to limit access to a breeder flock (with automatic recording of visitors and times) may represent a $13,500 investment. These funds could potentially also be used to purchase a piece of equipment that could immediately reduce the number of people required for a specific task, providing an immediate and easily quantifiable return on investment. However, the potential benefits in both cases should be assessed over the projected life of the equipment, considering the magnitude of the savings if this gate contributes to the prevention of a serious disease. In this case, of course, the return would be very high, but so may be the degree of uncertainty that this preventive measure will be effective.
Estimating the Risk of Disease
Estimating the risk of disease is also partly a subjective exercise. However, substantial evidence has been reported regarding major risks such as:
- Poor farm location: farm located in high density region (other farms within 2 km of premises);
- Introduction of birds of unknown origin;
- Introduction of contaminated material or infected birds;
- Presence of an infectious disease of interest in a region;
- Presence of this disease in neighbouring farms;
- Pest infestation (rodents and/or insects);
- Poor sanitation;
- No restrictions or requirements for visitors (i.e., high on-farm traffic, including hired help going from farm to farm);
These are common sense hazards that must be considered when estimating the risk of disease transmission. Although self evident, these risks are often ignored in practice. A similar situation exists in human medicine where significant health risk and protective factors are often neglected by patients. In the 1950’s, the United States Public Health Service developed the Health Believe Model to explain such behavior (Rosenstock, 1974). This model proposes that health risk assessment is determined by the individual’s perception of:
- His level of personal susceptibility to the particular disease;
- The degree of disability that might result from contracting this condition;
- The health action’s potential efficacy in preventing or reducing susceptibility or severity;
- Physical, psychological, financial barriers or costs related to compliance.
This model may very well apply to a grower’s perception of risk for his flock. One can also assume that this belief model pertains to the decision-making process of managers of integrated companies, shaping their appreciation of risks and of biosecurity measures. One supportive evidence is the fact that a similar proportion of poultry people comply with biosecurity measures as the general population does for disease prevention strategies designed to help them (Vaillancourt, unpublished data).
Table 2 offers an assessment of relative risk and of potential benefits based on the literature and on personal experience (Biosecurity in the poultry industry, 1995; Rossigneux, 1998; Wojcinski, 1993; Chiu, 1988). Of this list of usual suspects, one should consider in particular the following risks: poor employee training; lack of communication; lack of incentives for people associated with the farm; absence of a regional perspective; no auditing, and poor record keeping of the biosecurity system.
Assuming that Table 2 offers a valid assessment, it highlights the fact that many relatively inexpensive biosecurity measures may generate substantial benefits. Most are measures designed to control people access to the farm and to improve sanitation. However, these are dependent on compliance. In high density areas, a regional perspective is essential to the design of a biosecurity system, mainly in the face of an epidemic.
The cost-benefit assessment of biosecurity measures is determined by people’s perception of the level of risk to which they and their birds are exposed. This will also determine their degree of compliance with biosecurity measures.
The challenge is to convince all poultry personnel of the impact of their actions on the risk of breaking with an infectious disease. Education and communication are key factors in determining people’s perception of disease risks and, consequently, their assessment of the potential benefits of a biosecurity system.
Facts and Figures
Disease: Fowl Cholera
Type of Production: Commercial turkeys
Cost: $0.59/bird, $0.02/kg
Carpenter, et al. 1988
Disease: Reovirus infection
Type of Production: Broiler breeders
Disease: Influenza (nonpathogenic)
Type of Production: Egg layers, Pullets, Commercial turkeys
Cost: $1.67 to $2.94/bird, $5.05/bird, $5.83/bird
Disease: Influenza (Highly pathogenic)
Type of Production: Chickens
$6.06/bird (government expenses only), $19/bird (cost to industry)
Disease: Mycoplasma Gallisepticum
Type of Production: Egg layers
Disease: Coronavirus infection
Type of Production: Commercial turkeys
Rives, and Crumpler 1998
The estimated cost to the industry of the 1983-1984 Influenza outbreak in Pennsylvania based on the reported cost ($329 million in 2000 US dollars) published in a state extension document.
Procedures and Benefits
Partial list of biosecurity procedures and their relative cost independently of potential benefits ($$$ = very expensive; $$ = expensive; $ = inexpensive; ¢ = virtually no cost) and potential benefits (+++ = High; ++ = moderate; + = minimal)
Isolation (distance) from other farms and feedmill, slaughter plant, etc. $$$; +++; difficult to control over time.
Disposal of used litter away from all farms: $$; +++; difficult in high density regions.
Serologic monitoring: $$; +++; essential for regional level and farm level.
All-in, all-out production: $$; +++.
Introduction of new birds of known health status only:$; +++
Fence around premises: $$$;++
Gate at entrance of farm:$$; +++
Cost depends on quality; potential benefit dependents on compliance.
Sign advising to stay off farm if no authorization to enter:¢;+.
Parking area away from poultry barns: ¢; ++.
Requirements before a vehicle can enter:¢; +++.
Wash station for vehicles: $$; +++.
Use of locks for each poultry house: ¢; +++.
Dead bird disposal on farm: $$; +++.
Composting litter before removal: $; +++.
Removing litter after each flock: $$; +++
Downtime between flocks of at least 2 weeks: $; +++; can be expensive if much longer than 2 weeks but substantial benefits.
Pest control (rodents and insects):$; +++.
Access restricted if visitors
have been in contact with poultry: ¢; ++.
Shower in, shower out facilities: $$$; +++.
Coveralls provided by farm or requirement to wear clean coveralls: $; +++.
Clean rubber boots for all people on farm: $; +++.
Plastic boots for visitors: ¢; ++.
Changing clothing for employees leaving and returning to the farm on the same day: ¢; +++.
Auditing biosecurity rules: $; +++; compliance is critical for a biosecurity system.
The University of Alberta rewards excellence in teaching by individuals and groups. In the early fall of 2000 the seven person teaching team at the Alberta Poultry Research Centre received the award. This was the first time that the award has celebrated excellence in teaching at the group level.
To qualify, the teaching unit must have been in existence for at least three years. It may work at the graduate or undergraduate level and may include some or all members of a faculty, school, department or division, or may be an interdisciplinary team. Students taught by such a teaching unit must be able to identify results that they were taught by a group of instructors and not just a series of individuals.
The University of Alberta’s poultry group is made up of Dr. Gaylene Fasenko, Dr. John Feddes, Dr. Douglas Korver, Dr. Lynn McMullen, Dr. Robert Renema, Dr. Frank Robinson and Martin Zuidhof. To reflect their involvement with poultry, they are often referred to as the “Coop of Seven”.
Dr. Fasenko is a Research Associate, Avian Incubation and Embryology; Dr. Feddes is Professor, Animal Housing and Welfare; Dr. Korver is Assistant Professor, Poultry Nutrition; Dr. Renema a Research Associate, Avian Reproduction and Metabolism; Dr. McMullen is Assis-tant Professor, Food Microbiology; Dr. Robinson is Professor, Avian Physiology and Production; and Martin Zuidhof is the Poultry Specialist
with Alberta Agriculture, Food and Rural Development, who is working towards his PhD on bio-economic computer modelling of the broiler chicken supply chain. Details about the courses they teach, complete with colour graphics can be downloaded from the website: www.agric.gov.ab. ca/aprc/award.pdf.
In early 2000, the University of Alberta’s Student’s Union recognized three faculty members for their undergraduate teaching and mentorship skills. Two of the three—Professor Frank Robinson and Assistant Professor Doug Korver—were from the Poultry Group, which Dr. Ian Morrison, the Dean of the Faculty of Agriculture, Forestry, and Home Economics described as, “A group of enthusiastic, committed and innovative educators who I take great pleasure in nominating for the ‘Teaching Unit Award’.”
The Coop of Seven’s award nomination also included letters of support from the provincial Department of Agriculture, Food And Rural Development, graduate and undergraduate students. It also listed the awards and certificates of excellence earned by those who had completed the Poultry Group’s courses.
Those letters of support included phrases such as, “awesome course,” “the highlight of my university career,” “unbelievable assistance,” “unprecedented enthusiasm,” “impressive team... committed faculty,” and “the entire Poultry Group is without peer.”
The Unit Teaching Award carries with it a monetary prize of $3,500. It is indicative of the broad support that the Poultry Group has earned over the years that this amount has been matched twice–by Alberta’s poultry industry (the chicken, egg, hatching egg and turkey producer associations) and by the Depart-ment of Agricultural, Food and Nutritional Science at the University of Alberta.
The Poultry Group has announced that these funds will be used to enhance their creative teaching efforts in the poultry area.
“What I’m doing is just from a farmer’s point of view, using trial and error. I want to improve my bottom line and I found that adding whole wheat to complete feed did that,” John Bartel told me. He added, “As one nutritionist in Germany told me, ‘We sometimes do not know why some things work … but one thing for sure the farmers here in Germany and Holland have proven to us that it does work’.”
Later, Bartel said that he’d found that he shouldn’t fluctuate the wheat percentage up and down. “Don’t jump around unless you have a good reason.”
John Bartel was a dairy producer in the Chilliwack, B.C. area for 23 years until he sold out seven years ago. He now holds a 42,000 roaster quota, although he also manages a 1,600 head, free range, white veal calf operation. When his transitional quota is added in, it means he grows around 50,000 birds per cycle on average. To date his experience with feeding whole wheat has produced results better than he originally expected.
About three years back Bartel came across references to the addition of whole wheat to chicken rations in an effort to improve bottom line results. He found some references to the practice on the Internet and also talked to some Alberta chicken producers who had been using the strategy for a couple of years. One source was an article by Carlyle Bennett, a poultry specialist with the Department of Animal and Poultry Science, University of Saskatchewan, now with the Manitoba Department of Agriculture. Some information from his most recent report and his contact information is shown at the end of this article.
Then, while accompanying his daughter on a school trip to Europe, he spent a free day visiting farms. One of them had been using wheat added to complete broiler feed for some time with excellent results. Bartel reported that some European processors pay a premium for birds that were not over-fat and that the addition of whole wheat to the ration helped meet that goal.
Fast Growth, But More Flips
“The genetics of modern birds produces fast growth but a higher rate of ‘flips’,” Bartel said. “But I was told that restricted feeding reduced mortality by 1% as well as reducing feed wastage, which improves the feed conversion.”
He said that he started using wheat quite tentatively, starting with 6% on day 10, increasing by one-half percent per day to a maximum of 20%, continued right through to marketing. He’s used various different programs since then, even starting the flock with wheat at five days—which didn’t seem to provide much benefit for him. He has increased the percentage of wheat by as much as 1% per day, but this is dependent upon the quality of the broiler ration. When the percentage of additional wheat reached the 45 to 50% level he found that the feed conversion suffered, providing no net benefit.
With a mixed roaster flock the pullets are shipped first and the males later. He was advised to cut the wheat off early because of the stress caused by loading the pullets. However, he now feeds the wheat straight through without any adverse affect on his contamination rate.
“I’ve found that I get the best results by starting the flock at 10% additional wheat at 10 days of age, increasing this slowly up to a maximum of 35% wheat and continuing at that level straight through to slaughter.” However Bartel cautioned, “But I must stress that this is what I’ve found suits me based on my trial and error process. If anybody else intends to try adding whole wheat to their chicken ration they would be well advised to start at a more tentative level and build up their own experience before using the higher rates.”
In Case Of Health Problems
I asked Bartel if he has a pre-planned strategy ready for use if his flock encounters a health problem—such as enteritis. He replied that he monitors his flock closely and although he’s never found it necessary, he is always prepared to back off from the addition of wheat by 20% immediately. He said that he’s found that the addition of wheat to his ration has actually reduced his wet litter problem significantly. “I haven’t encountered an enteritis or cocci problem during the 2-1/2 years that I’ve been adding whole wheat to the complete roaster or broiler ration.”
Flock health has improved during his trial of the addition of wheat to his chicken ration, “You know the difference when you walk in to the barn,” he said.
With condemnations Bartel said it is hard to tell because they fluctuate throughout the year. “My condemnation rate with roasters had been around 3-1/2%, but now it runs consistently below 3% and overall results fluctuate less from flock to flock. The condemnation rate with my broiler flocks has ranged from a low of 0.69% to a high of 1.47%.”
Bartel admits that growth rate slows when wheat is first added, “But their legs are stronger, mortality is lower and the growth rate catches up after about two weeks.” He added that the flock’s feed conversion may be slightly poorer, but is more than offset by the lower overall feed cost. “The odd flock seems to be a day behind in weight, but when the feed conversion stays about the same, what is one day? And the litter is so much drier.”
He provided results from three recent flocks. The females were shipped at from 38 to 43 days, weighing from 1.88 to 2.20 kg. with plant condemneds from 0.87 to 1.65%. The males from these flocks were shipped at from 52 to 61 days, weighing 3.12 to 3.84 kilograms. Condemnations varied from 1.95 to 2.98 %. Included in this figure was from 0.39 to 1.35% attributed to ascites and from 0.29 to 0.92% due to cellulitis. Leg deformities range from 0.08 to 0.65% (with the 61 day old flock). Overall flock mortality ranged from a low of 4.39 to a high of 6.27% in the roaster flocks and between 3.5% to 5.5% with broiler flocks.
Bartel adds his wheat using a computer controlled, in-line weigh scale supplied by Fancom. The Fancom FWBU.e computer can be programmed to start adding a specific percentage of whole wheat to the complete feed on a specific day and to increase that percentage at a specific rate per day. Both complete feed and whole wheat fall in to the Chore-Time auger feeder hopper simultaneously. No special mixing paddles are required to provide a good mix.
Each floor of Bartel’s 400’ x 40’ double deck barn is equipped with 13 Shenandoah natural gas brooders per floor. Each has two lines off Chore-Time feeders and four lines of Chore-Time nipple waterers. One waterer line is equipped with ordinary nipples, the other three lines with button nipple drinkers. Lights are controlled by a Fancom dusk to dawn dimmer. The Fancom computers control fans, heat, the vent openings as well as the feeding system. Of course, using both complete feed and whole wheat, he has two feed bins, a 32 ton bin for the complete feed and the 16 ton bin for the wheat.
Aside from the cost of the extra bin and supply auger, Canada Poultryman understands that the cost of computer control and galvanized in-line weigh scale is under $8,000. Bartel summarized, “Results have been beyond expectations and investment pay-back has been much quicker than the two years I expected.”
Carlyle D. Bennett, Poultry Specialist, Manitoba Animal Industry Branch presented research findings about the use of whole grain and high grain diets with broilers, leghorns and turkeys at the 1998 Poultry Service Industry Workshop at Banff in mid-1998.
That talk re-inforced John Bartel’s recommendation of caution when trying wheat addition strategies. Bennett reported that in the UK and The Nether-lands, broiler rations have been diluted with up to 20% whole wheat. He said that the digestion of whole wheat requires a larger, more muscular gizzard, which can only be deve-loped over time–possibly as much as six weeks for optimum development. In the interim, some loss in performance occurs until the gizzard does develop. The question is: does the early slaughter of broilers provide sufficient time for the bird to develop the larger gizzard and gain back the lost performance. Bennett states in his article: “…broilers should not be fed over 30% whole grain.”
However, Bennett’s summary states that University of Saskatchewan trials show statistically significant reductions in leg and skeletal problems in one broiler trial and one tom turkey trial. In those trials, early growth rates were slowed and the most noticeable benefit was fewer valgus varus leg deformities.
Some references to other research into the use of whole grains provided by Bennett included a report by Forbes and Covasa of Leeds University (UK) (World’s Poultry Science Journal, Vol. 51. July 1995). This report indicated that high fibre diets reduced the incidence of coccidiosis.
However, they were unable to demonstrate why a muscular, active gizzard was able to reduce the incidence of oocysts. Carlyle Bennett has advised that he is prepared to send this 16 page article by “pdf” file attached to an e-mail message to those who request it. A “pdf” file requires you to have Adobe Acrobat Reader–a freely available program from Adobe’s website.
Alternatively, he’ll mail you a copy. Contact Carlyle Bennett at: Manitoba Dept. of Agriculture, Animal Industry Branch, Agric. Services Complex, 204-545 University Cresc., Winnipeg, MB R3T 5S6, Phone: (204) 945-0381, Fax: (204) 945-4327, E-mail: CBennett@agr. gov.mb.ca
John Bartel alongside his computer controls in his barn. His home computer is also able to monitor barn operations by modem. The galvanized, in-line Fancom weigh scale is fed by augers from his broiler ration and whole wheat bins. Specific percentages of wheat and complete feed are dropped into the supply hopper below and automatically mix as they are augered away to the feed lines.
John’s seven year old doubledecker broiler barn, with two bins alongside for wheat and complete feed.
The past decade in animal health has been influenced by an increasing consumer awareness, especially in Europe. That trend resulting in large part from a much faster exchange of news and information, is expected to continue with the same intensity throughout North America.
Some trade barriers are rooted in real food safety concerns, basically because of fear, but the politicians have to be concerned on behalf of the electorate. Consumers demand more than testimonials from experts and scientists. Many are fed up with the cheapest possible products and insist on quality in every respect, a demand extending to animal health industries.
Drugs and pharmaceuticals will still be developed but we will see no further development of antibiotics for some time because of steadily rising costs. The last antibiotic used in both the human field and animal husbandry was fluroquinolones, which have come under severe attack, not only from small consumer groups but from independent scientists and established national authorities. Animal health companies would be wise to pull out of the large animal market since the human market is much more lucrative and prestigious. The Danish experience has shown that other measures such as improved hygienic measurements and feed will give the same result as antibiotic feed additives.
Prudent trend setters in agriculture have set up better disease control systems and herd health survey systems in their barns in co-operation with the veterinary society. Hopefully, the vet society is aware of its responsibilities and will continue to master applied science. HACCP is a beginning.
The European ban on growth hormones is generally supported by consumers, but is under attack from British scientists who question the reasons behind the ban. And if the consumer is in doubt, she will not buy the product.
Introduction of genetically modified organisms (GMOs) is largely blocked by European consumers, and a campaign against GMOs has been launched in Canada. U.S. consumers have largely ignored the debate in Europe, although a bill may soon be introduced that would require labeling on meat products. The Food and Drug Administration will also review its policy on genetically modified foods.
Animal Health companies in the biological business are relatively safe. The general trend is toward prophylaxes. Vaccines based on new biotechnology have already been developed; for example, vaccines
for E. coli, equine influenza, Actinobacillus pleuropneumoniae, and Gumboro.
Marker vaccines that allow vaccination and eradication programs go hand in hand and we will probably see more of these. Conventionally developed vaccines, both live and killed, are generally of high standard and will continue to serve in the future. Biotechnology will help concentrate on specific attenuation and new ways of combining or compiling antigenic determinants for example, new combinations of
non-reactive Newcastle and a Marek’s disease vaccine are a possibility in the future.
What we probably will also see more of are vector vaccines, i.e. vaccines using a carrier virus with no pathogenecity to carry the wanted immunological determinants into the animal’s immunological system. This has already been introduced in small animal vaccines.
New carrier and delivery systems are being worked on. The most recent progress in modern vaccine technology is with intradermal or intramuscular application of so-called naked DNA. Much more work will be done on bacterial and protozoal disease protection using the new techniques.
Much of today’s work is focused on salmonella vaccines of different kinds and constructed in different ways. Salmonella is a disease which is here to stay and will continue as a potential threat to human food safety. Coccidiosis vaccines are used today only in breeders because of the cost, but will be tailor-made for the large broiler segment.
Presented at the Poultry Industry Council Poultry Health Conference in Kitchener, Ont.
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.
By any standards, there’s a lot less activity in Poultry Research and Education than was apparent twenty years ago. Obvious examples are the closing, in 1997, of Agriculture and Agri-Food Canada’s Centre for Food and Animal Research in Ottawa, and the progressive disappearance over two decades, of separate Departments of Poultry Science in several Universities. The federal presence in research with a specific poultry focus is now limited to one scientist working at the Agassiz station in BC. A few others work with birds from time to time, and this is also true in the university environment, but many commercial poultry producers would be hard pressed to identify a scientist they could consult on contemporary industry problems.
Two years ago, the Canada Branch of the World’s Poultry Science Association initiated a process to identify the resources available and the needs of science and industry for the next decade. This program was led by Dr. Roger Buckland of MacDonald College, McGill University. Buckland is a longtime poultry researcher, and former Dean of the College’s Agriculture Faculty.
Surveys were designed to identify all people involved in Poultry Research, Education and Technology Transfer, and to solicit from them their opinions as to the adequacy, or otherwise, of the available resources and output.
Of particular interest was the survey of industrial “users” of poultry science and technology: Do they have an adequate pool of expertise, and are people entering the industry adequately trained?
The results of the survey were presented and reviewed at a workshop held in Ottawa in November, and attended by more than sixty interested participants.
Workshop of Sponsors
- Canadian Agri-Food Research Council
- World’s Poultry Science Association, Canada Branch
- Agriculture and Agri-Food Canada
- Confederation of Canadian Faculties of Agriculture and Veterinarian Medicine
- Egg and Poultry Producers of Canada
- Poultry Industry Council for Research and Education
Dr. Bill Stevens from Guelph, Ont., gave the supplier perspective, and Dave Coburn, a producer from New Brunswick dealt with tech. transfer as a user. Stevens has been involved with another study, commissioned by the Poultry Industry Council, into the specific capability of the University of Guelph in the context of Ontario’s poultry industry, and he presented his results to the workshop. He spoke of the “Technology Train” consisting of basic research, leading to applied research, followed by technology transfer and commercial application.
Basic research is largely devoted to advancing scientific knowledge with little immediate direct application. It is funded largely by federal bodies such as the Natural Sciences and Engineering Research Council (NSERC) and provincial governments (OMAFRA in Ontario.)
Applied research is also funded by these groups but industry contributes in specific areas where immediate benefits in terms of practical knowledge are visible. Technology transfer is often aided by provincial governments but is also targeted by industry in terms of competitive advantage.
Commercial application has resulted in enormous gains in productivity over the past half-century, plus gains in efficiency and competitiveness. More recently, gains in quality assurance and food safety have resulted from the application of research.
Dave Coburn has enthusiastically embraced new technology in the past two decades, including a computerized layer barn, rapid composting of poultry waste and a state-of-the-art feed mill.
However, Coburn noted the decline in poultry research capacity in the past decade, particularly at the federal level, where expenditures of several million dollars shrunk to $768,000, with just one scientist dedicated to full time poultry research.
Now Is The Time To Rebuild
Coburn commented on lack of inter-University communication, as a serious problem, plus the apparent decline in tech. transfer resources. He said there is increased reliance on US data when Canadian data are lacking. Where provincial sources had disappeared, Coburn looked for the emergence of other vehicles for Tech. Transfer, including the Internet and a possible Virtual Poultry Department for Canada, one of the suggestions made by Roger Buckland in his questionnaire
Dr. Frank Robinson, of the University of Alberta, reviewed the results of Buckland’s survey of research resources. He said he found some poultry research in fifteen different institutions.
However, this is somewhat deceptive, because only nine showed one or more person-years of combined research, teaching and extension activity. Only in the Universities of Alberta, Saskatchewan, Guelph and McGill, were there more than four person-years. It was also emphasized that with the exception of Guelph, the majority of the positions were non-tenure, indicating potential lack of continuity if “soft” money is not renewed.
In terms of area of interest, most energy is devoted to nutrition (almost 10 person-years), with genetics and breeding (3.3), disease and pathology (3.6) some distance behind. Poultry production (2.8), physiology and biochemistry (2.7) and poultry meat science (1.3) were the only remaining fields with more than one person-year allocated. When one considers that this effort is spread across the entire country, the extent of Canada’s challenge in poultry science becomes clear.
The survey also reviewed the capacity for research in terms of facilities, and here the situation seems more favourable, with good facilities available for broiler and layer research available in several locations.
Fewer facilities are available for turkeys and broiler breeders, but these species still receive considerable research attention in relation to the size of the respective industries.
Imbalances seem to occur, however; University of Laval has capacity for over 2000 turkeys, yet none were used in the period under discussion.
A review of funding sources showed that slightly more than half came from industry with the balance from other grants. It is assumed that this funding does not include the provision of the infrastructure such as laboratories and animal facilities.
Robert Gauthier of Jefo Animal Health and Nutrition gave the perspective of the research user.
He painted a bleak picture of poor communication of results, inadequate funding compared with other animal species, and lack of coordination in priority setting and resource utilization.
Gauthier offered as solutions, the following:
- Definition of resources, priorities and research policies;
- Concentrate research among two or three solid institutions within Canada;
- Increase public and private (permanent) funding;
- Coordinate and integrate public and private research;
- Avoid spending private research dollars on administrative overhead;
In subsequent discussion of this presentation, Martin Pelletier, of the Canadian Poultry and Egg Processors Council, suggested at least one tool already exists for better communication and coordination of research. This is the Index of Canadian Agricultural Research (ICAR), which has recently been updated and is available on-line. From this database, researchers can rapidly extract very specific categories of current research. All scientists were urged to list their current projects on the Index.
Dr. Steve Leeson, University of Guelph, gave the “supplier” perspective on teaching and education in the field of poultry science. Some university agricultural science programs, including those at Guelph, no longer include “production type” courses. Teaching capability is much reduced compared with two decades ago. However, poultry species are used as examples in course work on scientific disciplines such as nutrition, genetics, physiology, etc.
Leeson, while acknowledging their need, questioned whether production courses were necessary at all institutions. A “Virtual Poultry Science Department” had been proposed in Dr. Buckland’s survey and received widespread support. Dr. Leeson suggested this may be a method of presenting production courses to students at a variety of institutions. He also suggested the same method for presenting industry to students. He has experienced great difficulty in getting access to commercial hatcheries, processing plants etc. because of biosecurity and other concerns.
Ted Bailey, from Landmark Feeds in Manitoba, gave the user perspective on poultry education.
His company employs a number of university-trained graduates in extension and administrative roles, and is probably typical of many organizations across the country. He underlined the need to inspire an interest in poultry early in students’ academic careers, and noted that success in this area is highly dependent on individual professors’ ability to spark that interest.
Bailey pointed to the Midwest Poultry Consortium, in the US, which had built up a system over the past decade embracing a number of universities which now cooperate in recruiting students and providing poultry production courses. Industry has spearheaded this initiative and supports it financially, as well as providing scholarship and internship opportunities for students.
This presentation further emphasized the need for active encouragement of students to enter the poultry field and then the provision of introductory and advanced courses to stimulate continued involvement pointing to an attractive career path.
While the use of the “Virtual Department” concept could contribute to these ideals, there would still be the need for the “evangelical professor” to get the process started with motivated students.
There is no doubt that these individuals are highly successful where they are active.
The delegates were assigned to one of five working groups to discuss these presentations in depth, and report back to a general session at the end of the day.
During these discussions, the potential role of the Poultry Industry Council for research and education was highlighted. Because it is an industry-funded group, the council is well placed to undertake some of the work of coordination, priority setting, and allocation of research funding.
It may also be in a position to initiate the so-called “Virtual Poultry Science Department,” whose major role might initially be the development of production-type undergraduate courses to meet the expressed needs of industry in the next decade.
Dave Nodwell, recently appointed Executive Director of the PIC, attended the workshop and participated in the discussions. He believes the PIC will rise to the challenge and become Canada’s voice in poultry research and education.
The conclusions of the discussion groups are being summarized and a complete report of the meeting is being developed by Dr. Buckland. Industry and the university community will then be expected to act on these findings to carry Canada’s poultry industry successfully into the future.
The emergence of antibiotic resistance among bacterial pathogens has become one of the most challenging crises to face public health authorities in the past century, said Rebecca Irwin DVM, MSc. Irwin is the food program coordinator for the Antimicrobial Resistance Project at Health Canada, and spoke as part of a panel at the Poultry Health Conference in Kitchener.
Many human pathogens are demonstrating resistance to antibiotics. The challenge now is to understand more fully why it has happened, to stop the trend and to find out how to prevent future development of resistance.
And that is why, rightly according to some researchers and wrongly according to others, part of the focus has fallen on the livestock industry and its use of antibiotics.
Dr. Maurice Smith, a veterinarian and a second panel member, said the poultry industry has been wrongly accused.
In his presentation, Smith displayed a recent headline and said it is incorrect. The implication is that if antibiotic use in the livestock industry stopped then things would be better. “This is a fallacy,” he said. Antibiotic use in the poultry industry is low and dropping, he stated.
He also pointed to numerous examples of situations where resistant strains of bacteria have appeared in countries where those antibiotics are not used in the livestock industry.
“We are a prudent industry,” he said. He stressed that the poultry industry seldom uses antibiotics and only does so when it has to. And he said that they are used properly.
Layers Rarely Get Antibiotics
Most egg producing flocks have never been given antibiotics and while turkey flocks receive antibiotics at hatching, many weeks pass before processing when no drugs are used. Meanwhile, the broiler industry has achieved a seven per cent reduction in antibiotic use in the last five years because birds reach market weight half-a-day to one day earlier and as a result consume less medicated feed.
He also pointed out that there are a lot of unknowns surrounding the issue.
Irwin said some bacteria have developed the ability to survive in the presence of antibiotics by mutating and changing their genetic make-up. There are now multi-resistant foodborne bacteria, she said.
“It is now recognized that the genes which are responsible for the resistance can move between and among bacteria of the same or even different species,” she said.
However, it is important to recognize that antibiotics are vital medicines for the treatment of bacterial infections in animals as well as humans, she said.
They are important for sustainable livestock production and for the control of animal infections that could be passed on to humans.
It is also recognized that the use of antibiotics in livestock, fish and plant production varies from country to country. In some countries their use is lower than in others and the use of specific antibiotics in livestock production is banned in some countries but not others.
Some countries report that more than 50 per cent of their total output of antimicrobial compounds is used in agriculture. “Most are applied to food animals in subtherapeutic doses as growth promoters.”
But many other countries have restricted the use of antibiotics useful in human therapeutics from use in growth promotion, she said.
Meanwhile concern over antimicrobial resistance is worldwide and the World Health Organization (WHO) has convened two meetings in the past year to develop recommendations on the use of antimicrobials in food production.
The WHO is supporting the development of guidelines which promote the “usage of antimicrobials which maximizes therapeutic effects and minimizes the development of antimicrobial resistance,” she said.
The WHO has also recommended that the use of any antimicrobial agent for growth promotion in animals should be terminated if it is used in human therapeutics or known to select for cross-resistance to antimicrobials used in human medicine.
In Canada, Health Canada’s Food Directorate is taking a lead role in the development of strategies to control the emergence and spread of antimicrobial resistance from agriculture and food sources.
In June, Health Canada sponsored a stakeholder workshop to provide a forum for discussion of topics related to prudent use, surveillance and research. Next, Health Canada will form a steering committee made up of representatives from government (federal and provincial), industry, public health consumers, diagnostic laboratories and academia.
“There is a critical need to provide the scientific information which characterizes the link between antimicrobial use in animals and resistance in humans and to answer questions on how resistance may be transferred to humans via food or environmental exposures. Increased collaboration and linkage of industry and government studies will enhance our ability to answer some of these complex questions,” she said.
Dr. Bruce Kilmer, of the Canadian Animal Health Institute (a trade association representing the developers and distributors of pharmaceuticals, feed additives, biologicals and pesticides), said each new microbial is reviewed by Health Canada’s veterinary drug program to ensure it doesn’t pose a risk to human or animal safety, does as the label claims, and is manufactured under good manufacturing conditions.
12 Years To Develop
It takes 10-to-12 years to bring a new food animal product from discovery to the marketplace at a cost of about $250 million, he said.
Antibiotics are used in agriculture to: assure safe and wholesome food from healthy animals; reduce human exposure to zoonotic pathogens through direct contact with animals; promote the health and well being of animals; and reduce the cost of food production.
Antibiotic use also keeps the cost of food down. A 1998 National Academy of Sciences study estimated that banning the use of antibiotics in production would raise poultry, beef and fish costs to the public by $4.85 to $9.72 per person per year.
There is also a public misunderstanding between resistance and susceptibility. Resistance means the bacteria no longer responds to treatment with antimicrobials while susceptibility refers to the sensitivity of the bacteria to treatment with an antimicrobial.
“Generally references to resistance in the popular press really refer to the fact that the bacteria is less susceptible to an antimicrobial,” he said.
Benefits Of Use Being Studied
The industry is taking a number of steps to address concerns. It has prudent use guidelines and Georgetown University is conducting a study, “Risk Benefit Analysis of Antibiotic Use in Food Producing Animals.”
The study is evaluating:
- the risk of treatment failure of human infections due to foodborne zoonotic pathogens;
- the benefit of reduced incidence of human infections due to foodborne zoonotic pathogens;
- the benefit to the environment and;
- the benefit to the economy.
Quality Assurance Programs
Meanwhile, producer groups are developing quality assurance programs and proper use of medication is an important component.
Challenges facing the industry include: meeting World Health Organization calls to tighten up regulations so that Active
Pharmaceutical Ingredients (API) are not used in food-animal production; and providing timely access to safe new products.
To answer the WHO’s call, Canada needs to implement new legislation to prohibit the use of API’s and to ensure access to new products Canada must resolve operational and personnel problems at Health Canada’s veterinary drug approval program and deal with the growing lag time in the registration of new products, he said.
The bottom line in the discussion is that decisions must be based on sound science, he stated.
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.
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.
U.K. study links chicken consumption to increased cancer riskEating chicken puts consumers at a higher risk of a…
Be Air-Aware: The impact of ammoniaOne of the biggest complaints surrounding the poultry barn –…
Researchers use laser to stimulate bird activityElizabeth Bobeck and colleagues at Iowa State University in Ames,…
Study finds many backyard flock owners not following proper hygieneWhile many people now keep chickens or ducks in their…