CPRC made a significant change to its funding process in 2012 by moving to a two-stage system. This new method includes an initial call for Letters of Intent (LOI) followed by a full proposal from a short list of projects drawn from the LOIs. The change allows CPRC to better tailor the research it supports to industry-identified priorities as laid out in the National Research Strategy for Canada’s Poultry Sector (the Strategy), available from the research page of CPRC’s website, www.cp-rc.ca. CPRC is now able to provide feedback to researchers (prior to the full proposal stage) on LOIs that are of interest but that may not fully address priority issues. This allows the researchers and CPRC to discuss changes in the objectives and/or work plan to more closely align the project with industry priorities.
CPRC’s call for LOIs was cancelled in 2013 so that funds allocated for research for that year could be directed to the new Poultry Science Cluster. The 2014 call for LOIs was issued in April with submissions due June 1st. This year’s call also included some additional changes to better align the LOI calls with industry priorities.
CPRC has used the following five research categories for funding calls for many years:
- Avian Gut Microbiology
- Food Safety and Poultry Health
- Poultry Welfare and Behaviour
- Novel Feedstuffs
CPRC also funds projects that are of significance to the Canadian poultry industry, but may not fit into the broad research programs listed above. Researchers may apply for funding for this category of research at any time throughout the year according to the CPRC policy on ad hoc proposals.
While the categories have suited CPRC’s purpose, they do not encompass all those identified in the Strategy that CPRC and industry have put so much effort into developing. The nine Strategy research categories are:
- Economic viability
- Food safety
- Animal Health Products
- Poultry health
- Poultry welfare
- Functional and innovative
- Poultry feedstuffs
The CPRC Board of Directors decided, at its March meeting, to align its categories with those in the Strategy. CPRC will now issue calls for LOIs based on individual categories or groupings of the Strategy categories. Groupings will be of similar types of research and some will closely reflect the categories that CPRC used through 2012. This year’s call for LOIs was for two category groups:
- Food Safety and Animal Health Products
- Genetics, Poultry Health and Poultry Welfare
LOIs do not have to address all aspects of each group but can target one or all of the priorities within the group. CPRC’s Board will review this approach at its July meeting as well as set the research categories that will be used for the next several years. This information will be posted on the CPRC website. The ad hoc category will be retained.
Many researchers and industry stakeholders have dealt with CPRC through Gord Speksnijder. Gord attended his first CPRC Board meeting in October 2003 and took over as Executive Director from Dave Nodwell a year later. Gord moved into the Research Coordinator role with CPRC in mid-2011 when operations were relocated to Ottawa. Gord has decided to step back from CPRC into an advisory role because of increased demands on his time from the family farm and a growing family. The CPRC Board, member staff associated with CPRC and CPRC staff are sorry to lose the regular input and exceptional advice that Gord has brought to the organization. His unique ability to view research from the point of view of a trained researcher and active farmer has been an asset that will be sorely missed. We wish Gord and his family all the best in their future endeavours.
The CPRC Board of Directors is appointed each year by its Member Organizations and consists of one representative from each of the five members. The 2014 CPRC Board was reappointed without change at the Annual General Meeting in March. Information on Board members and CPRC activities is available in its 2013 Annual Report posted on the website.
The membership of the CPRC consists of Chicken Farmers of Canada, Canadian Hatching Egg Producers, Turkey Farmers of Canada, Egg Farmers of Canada and the Canadian Poultry and Egg Processors’ Council. CPRC’s mission is to address its members’ needs through dynamic leadership in the creation and implementation of programs for poultry research in Canada, which may also include societal concerns.
Back in February the Agricultural Institute of Canada (AIC), commenting on the federal science and technology policy, applauded “the Harper government’s significant investments in science, technology and innovation.”
But, in a very gentle way, AIC Director of Communications, Daniel Kosick, pointed to a shortcoming. “It is important to remember that public support for basic research focusing on long-term advances is also needed,” he said in a release.
Basic research tends to be a tough sell, especially to self-identified “practical people”, which includes many, if not most, businessmen and politicians. They look for concrete developments or advances. The theoretical stuff leaves them cold.
It doesn’t help that those doing basic research can’t point to something concrete that might come from their work. But that isn’t their purpose. They are working to expand knowledge and it’s up to the rest of us to build on that.
An example of this is James Clerk Maxwell’s equations. These are the foundation of modern electrical and communications technologies. The computer this is being written on, the internet that provided some of the research material, the fancy new light bulb above my head, and even the poultry industry’s new high tech barns rest on the basic research carried out by Maxwell 150 years ago.
If you are getting lost less often than you used to it’s thanks to Albert Einstein. His theory of relativity allows GPS to work. Einstein also provided one of the most profound arguments for basic science. Without basic science, he said, there would be little or no applied science. Without applied science there would be little or no economic or social progress. My take on all of this is that if we don’t provide for the extremely smart people who think for a living the best we can hope for is stagnation. The worst is a repeat of the Dark Ages when centuries of progress was flushed away by superstition and individual aggrandizement in the form of castle building.
But Einstein can speak for himself. In a speech delivered in 1918 to the Physical Society in Berlin, he said many take to science “for purely utilitarian purposes” while others do it to show off their intellect. He continued that if these two groups were all there, there would be no science. It would be like trying to grow a forest with nothing but creepers.
Speaking of his own field of physics and the attempts to discern the general laws that govern everything, “There is no logical path to these laws.” It takes intuition, intense study and reflection, analysis of what is known (or thought to be known) and time.
Einstein knew the value of time. In his 1914 inaugural speech to the Prussian Academy of Sciences he thanked them “for conferring the greatest benefit on me that anybody can confer on a man like myself. By electing me to your academy you have freed me from the distractions and cares of a professional life and so made it possible for me to devote myself entirely to scientific studies. I beg that you will continue to believe in my gratitude and my industry even when my efforts seem to you to yield but a poor result.”
Many today say they believe in science and recognize the need to support it. But the reality differs from the words, especially in this country. The question is “How is Canada doing?” The most recent OECD figures (which date from 2010) are not encouraging.
The size of the research system as a percentage of GDP ranks behind Australia, Austria, Belgium, China, Denmark, France, Germany, the U.S. and numerous others. Canada is one of three OECD countries where the annual growth rate of GERD (Gross Domestic Expenditure on Research and Development) was declining. Canada was in the middle of the pack in the amount of GERD that is publically financed as a percentage of GDP. And it lags most other countries in terms of the growth rate of publically financed GERD.
These figures from the OECD’s stat extracts are, to put it mildly, embarrassing. They reflect a “penny wise pound foolish” mindset, or perhaps a nation that knows the cost of everything, but the value of nothing.
It is past time that we started focussing on the value of science rather than just looking at the cost and sacrificing the future for a few pennies of tax breaks today.
We need people who ask the fundamental questions and seek the answers. We need people who think for a living.
If you don’t believe it, argue with Albert Einstein.
Head and feather pecking behaviour in turkeys can escalate to severe pecking and cannibalism under commercial conditions, creating a significant welfare concern and economic loss. What causes this type of pecking, and what can be done to reduce its incidence?
In a review published in the World’s Poultry Science Journal* in December 2013, authors Hillary A. Dalton, Benjamin J. Wood and Stephanie Torrey examined the different types of injurious pecking in turkeys and the factors that may contribute to the behaviour, including environment, genetics and nutrition.
Injurious pecking can be differentiated as three distinct behaviours in turkeys. Head, neck or snood pecking is described as a form of aggression is often used to retain dominance and typically follows a social disturbance. Feather pecking occurs on many different levels, from gentle to more forceful repeated pecking or plucking of feathers on the back, wings and tail of another bird. In its gentlest form, feather pecking is considered as a form of social preening or investigatory behaviour; escalating to more severe feather pecking that involves loss and consumption of plumage and escape behaviour by the victim. If bleeding occurs as a result of feather pecking, the most severe behaviour of cannibalism
All three levels of injurious pecking behaviour result in animal welfare and production efficiency issues. While there is no consensus on the cause, injurious pecking behaviour may possibly be traced to a mismatch of the needs of young turkeys to the conditions supplied in a commercial environment. For example, it is possible that the fluorescent or incandescent lighting typically used in commercial settings may distort the appearance of emerging feathers and initiate investigatory pecking.
Toms are more likely than hens to exhibit head pecking behaviour, becoming more aggressive following sexual maturity. In the wild, young birds will head peck as a precursor to developing the skills required by mature birds to establish the “pecking order” in the flock. If this behaviour is learned, is it possible that isolating those individuals with a pecking propensity could help prevent the spread of this behaviour through the flock?
The need to peck is shaped by genetics, environment and nutrition. Current research in turkeys considers head pecking as an act of aggression but it can also represent re-directed foraging behaviour. A lack of environmental stimuli may be a motivator although some research has shown that birds still peck other birds even if foraging material is made available.
Farm management practices that may heighten stress on the birds, such as poor ventilation, inappropriate humidity,
temperature extremes, flies or parasites, high stocking densities, inappropriate lighting, management changes or foot problems may contribute to injurious pecking.
Interestingly, unlike other forms of injurious pecking, the rate of aggressive head pecking in turkeys is affected by familiarity of the birds. Male turkeys will peck unfamiliar individuals in a group as small as four birds.
The presence of numerous confounding variables has prevented meaningful insight into the relationship between genetics and injurious pecking. Has selection for larger, faster-growing birds unintentionally selected for higher rates of aggression? When exposed to similar environments, traditional lines displayed fewer injuries than modern lines, but it is difficult to specifically pinpoint the traits involved.
Pecking behaviour may also arise as a result of a nutritionally unsuitable diet or inappropriate feed form. Studies have shown that turkeys fed a crumble or mash diet versus pelleted, with higher fibre, and provided free choice instead of restricted, spend more time foraging and less time feather pecking.
Beak trimming with infrared lasers immediately following hatching is the current practice used to reduce injurious pecking. While preferable to hot-blade beak trimming, there are still concerns about the procedure being performed without analgesia. It is also possible that beak trimming increases the incidence of feather pecking by increasing frustration in the bird’s physical inability to grasp the feathers.
Lower light intensity is often employed to reduce injurious pecking but it may also lead to eye abnormalities and musculoskeletal disorders; reduced lighting also hinders the detection of injured or lame birds. Removing the snood from toms, another common procedure, can also lead to chronic pain if not done correctly.
As stated in the World’s Poultry Science journal article, “Concern over trading one welfare concern for another has fostered interest in developing less drastic alternatives, such as genetic selection for gentler birds, environmental enrichment, and changes to diet, to reduce injurious pecking in turkeys…With this information it should be possible to design strategies to reduce injurious pecking, to lead to improvements in both welfare and production.”
The researchers are supported through the Canadian Poultry Research Council, Poultry Industry Council, Hybrid Turkeys and Agriculture and Agri-Food Canada.
*Dalton, H.A., B.J. Wood and S. Torrey. 2013. Injurious pecking in domestic turkeys: development, causes, and potential solutions. World’s Poult. Sci. J. 69:865-876
The road from research discovery to commercial application is sometimes long. In the October 2010 issue of the CPRC update, we introduced you to new vaccine technology being developed by Dr. Eva Nagy and her team at the University of Guelph. Since that time, these researchers and the University have been busy refining the technology and working with Avimex Animal Health to bring it to commercial application.
While vaccines are used with great success to protect poultry from a range of diseases, many are not without their drawbacks. Vaccines based on live virus, for example, can sometimes cause symptoms of the disease they are designed to prevent. Killed vaccines are generally safer, but are often less effective. As more is learned about pathogens and the host’s immune responses to them, new vaccine types are emerging that overcome the shortcomings of their predecessors and incorporate features that improve their effectiveness and utility. For example, scientists have identified specific viral proteins that elicit a protective immune response. Inoculating birds with these immunogenic proteins, or “antigens”, eliminates the need for, and associated risks of, using intact virus. The challenge is to find an effective way to deliver these antigens to the body.
The technology, in brief
Dr. Nagy’s team is meeting that challenge by exploiting a virus’ natural ability to deliver genetic information into biological cells. Specifically, the researchers are working with a strain of fowl adenovirus (FAdV-9; a strain that does not cause disease in poultry). Adenovirus particles are extremely small and, compared to a cell, are quite simple. They consist only of a set of genetic instructions (DNA) and a coat of protein that protects the DNA. Adenoviruses do not have the chemical machinery necessary to reproduce themselves. As part of their lifecycle, these viruses attach to a host cell and introduce genetic instructions that trick the cell into producing new virus particles. Nagy’s team engineered FAdV-9 to instead instruct the cell to make specific antigens. These antigens are, in turn, presented to the immune system to elicit the appropriate immune response.
The FAdV-9 system is very powerful and flexible. Using the same biological platform, a wide array of antigens can be produced. Antigens can be co-introduced with proteins that enhance the bird’s immune response. Multivalent vaccines can be produced that simultaneously protect poultry from more than one disease. Additionally, these vaccines can be engineered to allow distinction between birds that were vaccinated and those that were naturally infected by intact virus. Formally known as “Differentiation of naturally Infected from Vaccinated Animals” (DIVA), this feature will be an important component of many commercially viable vaccination strategies in the future.
The key to bringing scientific discoveries to commercial application is to connect research expertise with companies that can take the technology to the marketplace. In Dr. Nagy’s case, this connection was made with the help of the Catalyst Centre (CC), the University of Guelph’s technology transfer and industrial liaison office. The CC works with faculty, staff and students “to protect intellectual property and maximize potential economic, social and environmental benefits.” CC staff connected Dr. Nagy with Avimex and helped navigate issues around intellectual property and technology licensing. Avimex, based in Mexico (there are no Canadian vaccine manufacturers), produces poultry vaccines and pharmaceuticals for poultry and other agricultural species for markets in more than 25 countries. Having done its own due diligence, Avimex is confident that Dr. Nagy’s technology platform will be a success and is working on registration and scaling up production.
Congratulations to Dr. Nagy’s team on their ingenuity and perseverance, and to the Catalyst Centre and Avimex for helping these researchers navigate the long road from idea to marketplace.
Funding for Dr. Nagy’s preliminary work was provided by CPRC in partnership with Agriculture and Agri-Food Canada (AAFC) and the Natural Sciences and Engineering Research Council. Ongoing research was part of the 2010-2013 Poultry Science Cluster, which was funded in large part by AAFC Canada as part of Growing Forward, a federal-provincial-territorial initiative. CPRC and a number of industry and government organizations also provided funding for the Cluster.
The membership of the CPRC consists of Chicken Farmers of Canada, Canadian Hatching Egg Producers, Turkey Farmers of Canada, Egg Farmers of Canada and the Canadian Poultry and Egg Processors’ Council. CPRC’s mission is to address its members’ needs through dynamic leadership in the creation and implementation of programs for poultry research in Canada, which may also include societal concerns.
March 19, 2014 - Canadian poultry producers can now access detailed management information for a costly disease in a user-friendly format.
A unique self-guided educational DVD and smart phone accessible website contains information to arm producers with the scientific knowledge they need to manage coccidiosis. The DVD will be distributed with the April issue of Canadian Poultry Magazine. The DVD’s cover will feature a QR code for a complementary website with additional features (www.uoguelph.ca/cocci).
Coccidiosis, caused by the Eimeria parasite, is a common disease for both large and small poultry operations that can impact gut health and performance with a significant economic impact for producers.
The Eimeria parasite is hardy, says Kayla Price, a University of Guelph doctoral student researching coccidiosis management and control, supervised by parasitologist Dr. John Barta. “You can’t easily eradicate it, but you can look at options to manage it.”
Bridging the gap between scientific research and agricultural producers is one of the most important steps in helping producers manage this common poultry disease, says Price.
Vaccination and preventive anticoccidial medications are already being used in flocks, but understanding the basic biology and life cycle of the parasite helps producers to manage it better, says Price. This background also helps producers ask the right questions to, and work more effectively with, their veterinarian, their feed mill and pharmaceutical representatives.
Funded by the Ontario Ministry of Agriculture and Food’s (OMAF) Knowledge Translation and Transfer (KTT) program, the Poultry Industry Council and members of the poultry industry, the resource brings information together in one user-friendly format.
The resource includes insights and suggestions to small flock and commercial producers for pullet, broiler, turkey and game bird operations, feed dealers, veterinarians, government, academia and industry members, bringing practical on-farm management methods together with scientific research. Producers can access information targeted to their type of operation.
Price wanted the resource to be as comprehensive as possible, with information for as many production systems and control methods as feasible. It also addresses the challenges of Canadian poultry production and climate.
It is important to keep the approach and information as generic as possible and minimize the use of scientific jargon, says Price. “This approach facilitates learning and makes academic research accessible.”
The project committee members include: Price, Pathobiology Department, University of Guelph; Dr. Gregoy Bédécarrats, Animal and Poultry Science Department, University of Guelph; Dr. Michele Guerin, Population Medicine Department, University of Guelph; Dr. Csaba Varga, Ontario Ministry of Agriculture and Food; Kobus Van-Heerden, Ceva Animal Health; Laura Bowers, Poultry Industry Council; and Dr. John Barta Dept. Pathobiology, University of Guelph.
The continually increasing growth rate of modern broilers allows each new generation to reach market weight approximately half-a-day faster each year.1 Despite changes in the rate of growth of broiler stocks, the target growth profiles used in broiler breeder feed restriction programs have changed little in past 30 years.2 As the growth potential of broilers continues to increase, the degree of feed restriction required to manage parent stock body weight gains has created a more competitive feeding environment.
Whereas the poultry breeding companies have worked to maintain or even increase rates of egg production and hatchability, achieving these potential results at the broiler breeder farm level on a consistent has been challenging.3 Production of viable chicks ultimately defines success in a broiler breeder operation. Strategic use of feed ingredients and effective feed delivery contribute heavily to this success. The hen diet can be changed in ways that increase embryo viability, support development of the immune system, and at times even influence broiler yield. As these effects can change with hen age, it is important to understand some of the more influential maternal nutritional effects on the broiler offspring. The nutrient composition of the egg is affected by maternal nutrition, body composition, age and strain. These traits, as well as incubation conditions, can affect chick well-being, growth, and immune function. This paper examines some of the key attributes of maternal nutrition and management that can affect broiler chick quality and growth.
Selecting for Growth Affects Body Composition
From the perspective of parent stock managers, modern broiler strains are simply too good at depositing breast muscle. With a propensity to deposit muscle rather than fat, there may not be enough energy stored in the body to mobilize in times of energetic shortage, and as a result broiler breeder hens may have difficulty with early chick quality and long-term maintenance of lay. Carcass fat in feed restricted birds at sexual maturity averages between 12.5 and 15 per cent of their body weight and has been trending downwards.4,5 Apparent reductions in fat content in current stocks are likely a reflection of the increased muscling that has occurred.
How do we grow the bird at an appropriate rate while ensuring the carcass stores are present to support long-term egg production without letting egg size get out of hand? The bird used to be a lot more forgiving. The use of non-traditional feed allocation profiles has shown the large impact of current feeding level on ovarian morphology parameters. Current feeding level can be more important than body weight in its influence on egg production. Thus, there is potential to use feed to manipulate body composition to optimize egg and chick production.
Managing Lifetime Nutrition
By the time sexual maturation begins, managing nutrient intake of the bird is a combination of current feeding level within the context of previous feed allocation decisions. Because current broiler breeder stocks are less able to store fat and grow more muscle when overfed, what the bird consumes today has a much greater impact on productivity than it used to. There is less of a buffering effect from fat stores, and the bird must rely more on protein stores and on dietary nutrients. If the energy needs of the birds have been met today, the right signals proceed between the gut, the brain, and the reproductive organs to maintain a high rate of productivity. When too much is fed, additional nutrients are first shunted towards growth. When not enough is fed, cuts to reproduction now tend to be first on the list.
In previous trials we have noted that at the end of lay (approximately 60 wk of age) there is less fat and ovary mass in birds carrying a higher proportion of breast muscle. However, while examining this relationship more closely in a recent study, we noted that while breast muscle weight was negatively correlated with abdominal fatpad weight (r = -0.735; P < 0.0001), neither were correlated with ovary weight (Renema, unpublished data). In this study comparing various dietary energy:protein ratios, we found that birds were able to shift the balance from skeletal muscle to egg production to some extent. While the hen can use both carcass fat and protein as energy sources, the metabolic priority is to maintain protein, and hens will catabolize their own muscle tissue only as a last resort. A bird with more carcass fat is better equipped to tolerate day-to-day changes in feed availability.
Ekmay et al. (2010) worked with isotope-labeled lysine and found that while early in lay there is a high reliance on skeletal muscle turnover for egg formation, later in lay the reliance on dietary protein increases. In contrast, fat to support yolk formation comes primarily from lipid synthesis early in lay, but shifts to a more even division between lipid synthesis, dietary lipids and tissue fat later in lay.6 Support of the ovary appeared to be more closely tied to dietary energy level during the laying phase, with both ovary and liver weights being higher when a higher energy ration was fed (Renema, unpublished data). A bird with more carcass fat could be better equipped to tolerate day-to-day changes in feed availability.
In the broiler breeder research program at the University of Alberta we have recently confirmed that feeding in the pullet phase has a more long-term effect on productivity than previously thought. Basically, feeding program, feed restriction program, and how we follow the body weight targets in the growing phase all have a greater affect on final carcass composition at the end of egg production than the diets fed during the egg production period have. This is partly because muscle deposition is ‘set’ when they are young and frame size is ‘set’ as soon as the reproductive hormones begin to increase during sexual maturation, and these both have carry-over effect into the breeder phase.
In addition, we have found that the change in energy:protein ratio during the transition between rearing and breeding phase can also affect long-term breeding success. It is possible to hurt long-term egg production and even broiler offspring yield based on choice of pullet and layer diets. Moraes et al. (University of Alberta, unpublished data), reported that if the energy:protein ratio decreased between the rearing and breeding phases, broiler offspring yield was negatively affected. As an example, moving from a higher energy ration in the rearing period to a lower energy ration during the breeder period, which results in a drop in the energy to protein ratio, also hurts broiler offspring breast muscle yield and overall carcass yield by approximately 1% (19.8% vs. 20.9% breast muscle) when compared to treatments where the energy:protein ratio remained the same or increased between the rearing and breeder diets (Moraes, unpublished data). The bottom line recommendation is not to overfeed protein when transitioning from rearing to lay.
Low protein in the layer ration may affect gene expression related to breast muscle development in the offspring. This is known as an epigenetic effect. Rao et al. (2009) reported that offspring of Langshan breeders fed 10% vs. 15% CP diets had heavier breast muscle by 4 wk of age. Offspring of the 10% CP hens had an up-regulated expression of insulin-like growth factor 1 (IGF-I) and type 1 insulin-like growth factor receptor (IGF-IR) mRNA in the breast muscle. IGF-I is a regulator of bird metabolism and muscle development and increased expression of IGF-I will result in increased breast muscle.8 Our observation that pullet phase nutrition had more influence on broiler offspring than the nutrition during the laying phase (Moraes, unpublished) supports the idea that there may be an
Who Benefits from High Flock Uniformity?
Good body weight uniformity in the pullet flock is one of the ways we can increase the predictability of the response of the pullet flock to both photostimulation and the slightly more aggressive feed changes associated with the sexual maturation period. While not perfect due to the existence of plenty of bird:bird variability in feed intake and growth patterns, uniformity can help to ensure we are over- or under-feeding as few birds as possible as egg production starts and subsequently when post-peak feed reductions are imposed. The bird:bird weight variability can have a behavioural component, with some birds eating more aggressively than others, and an energetic efficiency component. Small birds in particular are often found to be less energetically efficient. Less efficient hens have a higher regulatory thermogenesis, resulting in the loss of more energy as heat.9 If these less efficient birds also get behind in body weight compared to their flock-mates, they will often also mature later, and with less robust ovarian development than their larger flock-mates.
What happens to the ovary development and egg production traits of the outlier pullets if their growth profile is allowed to continue in parallel to the target flock body weight curve? To test this we randomly divided pullets from all over the flock body weight distribution onto BW target profiles either at target or 150 g above or below target. For the offspring, the biggest impact of modifying BW targets was with egg size and subsequent chick size. No egg production traits were affected and all broiler trait differences could be explained by the treatment affects on egg size (Renema, unpublished data).
A common assumption regarding flock body weight management is that productivity will be maximized if body weight uniformity is high – with the ideal case being that all birds had the exact same body weight. To test this, we maintained a group of broiler breeder pullets on a common feed allocation, or individually managed birds from 16 wk of age to all be at the target body weight. Body weights of individually managed birds had a very good uniformity (CV=1.9%) from 20 to 60 wk of age compared to the group-fed birds (CV=5.4%). With the larger birds, egg size will be an issue.
Decreasing body weight of heavier pullets from 16 wk to reach the target weight did not significantly affect their egg production. However, a very pronounced effect was found when underweight pullets were forced to the target. These birds produced as much 15 total eggs more than control underweight hens (Figure 1). The problem, for Canadians at least, was that 11 of these 15 eggs were lighter than 52 g – the threshold for incubation. It is clear that improving the body weight profile of underweight birds have the potential to significantly improve broiler breeder productivity.
The increased egg production results for the low efficiency birds fits with hormone profile work of underweight pullets during sexual maturation. In this work, pullets beginning 20% lighter than the flock mean will mature more slowly than standard pullets or 20% heavy pullets unless they are given a 20% boost in their feed allocation. Plasma estradiol-17b concentrations demonstrated that ovary development in the overfed small pullets was proceeding like that of their standard and high weight counterparts.
Feeding the entire flock at a higher level would result in overfeeding in the Standard and High weight birds.10 At some point the practice of sorting small birds into a separate area and feeding them either without competition from larger birds or possibly at a higher level may become cost-effective to consider. From a management perspective, correcting the body weight profile of higher weight birds has no impact on flock productivity while correcting the weight of the underweight pullets did have a positive impact on overall productivity -- provided the mean body weight of the population is under control, i.e. close to the body weight target.
To truly see the impact of a tight uniformity, a treatment like this should be started at a much younger age to eliminate biases that might be introduced by early growth profile. Careful attention to feeder space and even initiating a sorting program during the pullet phase can help generate a group of birds with uniform BW going into the breeder house. With females maturing within a shorter age range today, there may be fewer issues with male intimidation of females that are not yet receptive to mating. This can contribute to a more stable, long-term sexual behavior in the flock.
A flock that has high body weight uniformity values coming into lay may not continue this way. Within a hen population some hens lose weight in time – often as a result of a high rate of lay, while some gain weight due to a poor rate of lay. However, other groups exist within the population that can both gain weight and produce large numbers of eggs, or do the opposite (Renema and Zuidhof, unpublished data). As a result, the average weight birds at the end of lay include the best layers of the most energetically efficient birds (lost weight), the worst layers of the least energetically efficient birds (gained weight), and the average layers of the average efficiency birds (remained average weight throughout). As a result of this variability, later in the egg production period it is much easier to interpret the relationship between male size, appearance and reproductive effectiveness than it is for the females.
How has Genetic Change Impacted Flock Management?
Egg Size: Genetic selection programs in table egg stocks compared to broiler stocks have affected reproductive traits differently. In laying hens, earlier maturation and higher rates of lay have led to potential skeletal issues due to the challenge of maintaining support for shell formation. While increasing egg size with age is an issue in both laying and broiler breeder stocks, in table egg production this is much easier to manage using nutritional tools. Unfortunately in broiler breeders, once you move beyond methionine and start reducing various combinations of choline, folic acid, and vitamin B12 that can work well in laying hens), you are reducing micro-ingredients essential for broiler hatchability.11
A general uneasiness to commit to a defined post-peak feed withdrawal program in broiler breeder flocks could be largely responsible for current issues with large egg size in older broiler breeder flocks. Issues with late egg weight within the breeding companies may not be the same as what is faced on commercial farms. Under conditions of overfeeding, egg weight was much more responsive in commercial strain crosses than in pure lines (Figure 2).
Figure 2. Egg weight of pure lines (1 to 4) or of commercial and experimental strain crosses (5 to 8) fed a standard ration (R) or overfed 20% from placement in the layer barn (OF)
The egg can be affected very quickly by fluctuations in feed intake. There is a short term effect of changes to feeding level on egg size, for example. The albumen content reacts to changes in energy intake immediately, while yolk size is slower to respond. Unfortunately, the yolk tends to only trend upwards in size. A reduction in rate of lay means the hen has more yolk material available to spread across fewer yolks, thereby increasing egg size. As a result, the most effective approach to controlling egg size is still to maintain as high as possible a rate of lay later in production.
In contrast to table egg laying hens, broiler breeder hens lay at a lower rate and have a higher body mass – both of which contribute to less stress on calcium supplied by the diet or skeleton. The shell quality issues that have appeared in some flocks after 40 to 45 wk of age can typically be easily remedied by the supply of some large particle calcium. There may be a feed formulation or diet density trigger in flocks where shell issues appear. We have recently begun to see examples of shell quality issues confined to specific feeding treatments with no obvious reason for the shell quality differences among groups.
Can feed restriction be relaxed and birds allowed a less restrictive growth profile? In a comparison of a range of both pure lines and commercial lines, providing 20% extra feed reduced productivity and shell quality (Table 1). On average, egg production was reduced by 12.5 eggs (8.3%) under these conditions. This is in contrast to underfed birds, which we have shown will cease egg production all together with just a 9% drop in feed allocation (86% vs. 63% of birds still in production at 65 wk in Control and -9% groups) (Renema, unpublished). In time of energetic stress, reproduction is one of the first things the bird will sacrifice – instead diverting nutrients to maintenance and survival.
A flock can transition from being on the target body weight profile to overweight over just a few weeks time – often as the birds reach peak production and ‘overshoot’ the weight targets. As the birds are transitioned from feed increases during sexual maturation to post-peak feed decreases, they grow more energetically efficient. This same phenomenon occurs during the transition onto feed restriction from full feeding in the first few weeks after breeder chick placement. As these hens are able to utilize the feed more efficiently in the short term, the initial feed withdrawals may not be as effective as hoped, leading to the hens getting too heavy.
In warm environments, overweight birds can be the result of not compensating for the higher barn temperature with a lower feed allocation. As long as the feed is formulated to ensure adequate supply of the micro-ingredients on a daily basis, focusing on a body weight target rather than a feeding program can help ensure body weight does not become excessive.
Lighting: The majority of research on daylength and light intensity has occurred in laying hens. At current commercial light intensity levels, we have not been able to demonstrate any significant effects on reproductive traits. Concerns with high light intensity in broiler breeder barns has so far proven to be of little consequence. However, the results we have seen demonstrate that ovary development is affected in extreme cases (particularly low light intensity), demonstrating that these effects should continue to be monitored.
New LED lighting systems have the potential to be produced with very specific blends of light wavelengths. New lights are being produced that have claims of encouraging more efficient growth, for example. This is presumably achieved in part through behavioral modification, as evidenced by anecdotal reports of ‘calmer flocks’. Some red light will always be necessary to support reproduction since these wavelength have the greatest ability to penetrate through the feathers and skull to the light-sensitive neurons associated with gonadotrophin producing neurons. Too much red light has anecdotally been shown to cause undesirable behaviour aviary-housed laying hens, demonstrating it is important to work with companies familiar with how their products have been tested in agricultural environments.
Fertility: Assessing flock fertility comes down to one main theme – if you don’t have mating, you won’t get fertile eggs. A good female flock can come out just average for chick production if the males have been ineffectively managed. While there are some nutritional components to male fertility (antioxidants and minerals like Zinc, Choline and Selenium that contribute to both sperm production and sperm survival in the female reproductive tract), reproductive behavior of the flock must be managed appropriately to maintain long-term flock fertility.
Heavy birds are an issue, as it can impact physical traits such as footpad condition and cause pain. If the male is sore, the last thing it wants to do is mate, and if it is mating it will be much less successful at it. Rapid declines in flock fertility are often due to insufficient bodyweight control. Hocking et al. (2002) reported that feed restricted and overfed hens have similar fertility when provided a similar semen source, but overfed hens have a reduced hatchability due to an increase in late embryonic death. Duration of fertility (measured by monitoring fertility in consecutive eggs) is also reduced under conditions of overfeeding.13 Nutritionally, too much protein is bad for yolk membrane strength and embryo survival. Underfeeding hens, while being potentially detrimental to rate of lay, does not appear to hurt fertility or hatchability.
Many aspects of mating and dominance behavior cross the boundaries of breed. We can learn a lot from table egg laying hens reproduction and even from wild poultry species. Female preferences for dominant males can be problematic in flocks with heavy males. Modern broiler stocks have been selected for a shorter, wider-legged stance to support rapid broiler growth. In the breeder, shifts in body conformation have the potential to affect how well the male and female are able to make sexual contact during the act of mating in heavy flocks. The behaviour of these birds suggests they think it was a completed mating when no semen transfer occurred. As this likely affects mostly older, heavily muscled males, this could become a criterion for male culling. Unlike underweight males who may express less sexual behavior due to decreased testicular mass and testosterone production, these large males are often still perfectly functional, and only serve to disrupt mating activity of subordinate males. Flock fertility results don’t show which males are working and which ones are lame, too big, or just sore enough in the feet and leg joints to not want to bother to mate. Managing flock fertility requires spending time observing flock mating activity and assessing all males for potential culling. The best males in the younger flock could be the ones causing the most trouble in the older flock if they are not able to complete matings.
The broiler breeder of tomorrow will require a higher degree of precision in its feeding. Increasing vigilance is needed in the areas of feed composition and maintaining consistent body weight gains through careful decisions about how much and how often to change feed allocations. Extra attention to detail can make it possible to change body weight targets, but make sure the intended consequences actually do occur rather than negative unintended consequences. Effective management of these flocks needs to ensure managers are able to deliver the right nutrition to the bird WHEN they need it. Using this approach can enhance late egg production, control egg size and contribute to improved embryo survival and even broiler yield traits. The ability to think of daily nutritional decisions in a broiler breeder operation within the context of the entire life history of the flock will become a more important aspect of broiler breeder management and feeding.
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- 10. Renema, R. A., and Robinson, F. E. (2004). World’s Poultry Science Journal, 60: 511-525. Goerzen, P. R., Julsrud, W. L., and Robinson, F. E. (1996). Poultry Science 75:962-965.
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- 13. Goerzen, P.R., Julsrud, W.L., and Robinson F.E. (1996). Poultry Science 75:962-965
A number of poultry industry groups are using a less costly method to collect avian influenza virus samples, thanks to U.S. Department of Agriculture (USDA) scientists.
At the Agricultural Research Service’s (ARS) Southeast Poultry Research Laboratory (SEPRL) in Athens, Ga., scientists conduct studies not only to identify various avian influenza virus strains, but also to determine their origin and whether current tests and vaccines are effective against them. In addition, the scientists investigate the best methods for collecting virus samples from poultry for testing.
In the United States, all meat chickens and turkeys must be tested for avian influenza before processing. Sample collection is an important component of this process.
A certain number of swab samples, taken from inside the birds’ mouths, are needed per flock to get a reasonable virus sample, according to microbiologist Erica Spackman, who works in SEPRL’s Exotic and Emerging Avian Viral Diseases Research Unit. The current method used to determine if virus is present works well, but requires placing only one to five swab samples in a tube.
Spackman found that improvements could be made by switching the type of swab used and increasing the number or swabs in each tube.
“One of the most important variables is the number of swabs required—the sample size we take from inside the mouth of the chicken or turkey to see if the virus is there,” Spackman says. “We need to collect a certain number of swab samples per flock to get a reasonable virus sample.”
Swab samples are collected from the same flock and put into tubes for testing. Traditionally, each tube contains 1-5 swab samples. The idea was to determine whether more swab samples could be pooled together into a single tube without inhibiting or affecting the sensitivity of the test.
Spackman found that putting 1, 5, or 11 swab samples in the same tube did not affect testing. A similar experiment with Newcastle virus samples had the same results.
This research, which was published in BioMed Central Veterinary Research in 2013, supports the USDA’s priority of promoting international food security.
ARS is USDA’s principal intramural scientific research agency.
Minister Gerry Ritz announced that Agriculture and Agri-Food Canada (AAFC) will contribute $4 million to Canadian poultry research under the AgriInnovation Program (AIP), part of Growing Forward 2. The announcement was made at Kay House at the Arkell Poultry Research Station, University of Guelph on Feb. 18. Funding will support a Poultry Science Cluster, which CPRC will administer. CPRC was the recipient of funding for research for a previous Poultry Science Cluster under the first Growing Forward program that concluded March 31, 2013.
A “cluster” brings together multidisciplinary teams of scientists to solve complex problems and to create synergies in research efforts. It is a way to make the most of available resources and supports a strong business case for investing in Canadian poultry research. Pooling intellectual and financial resources to address issues of common interest is a powerful way to maximize the impact of our collective investment in research.
Total funding of almost $5.6 million, including industry contributions of $1.45 million and the balance from government, will support 17 research activities on four themes that reflect industry priorities as identified in the National Research Strategy for Canada’s Poultry Sector, available at www.cp-rc.ca under the Research tab. Cluster research themes include:
Poultry Infectious Diseases, as they impact poultry health and/or zoonosis (four activities).
Alternative Animal Health Products and Management Strategies that enhance avian immune function and mitigate the impact of infectious pathogens while displacing the need for traditional antimicrobials (four activities).
Poultry Welfare and Wellbeing throughout the production chain, as impacted by early immune function, bird harmony within various alternate farm production systems, bird stocking density, and the effects of temperature extremes during live bird transport (five activities).
Environmental Stewardship as impacted by emissions of particulate matter, ammonia and greenhouse gases and their effect on poultry, poultry workers and the industry’s environmental footprint (four activities).
Anticipated outcomes of the Cluster research include:
- As an extension of work accomplished in the first Poultry Science Cluster, an increased understanding of the biology of necrotic enteritis (NE) and continued progress towards an effective vaccine that can be used to complement current NE-management strategies
- Optimization and validation of a prototype avian influenza vaccine and vaccine delivery method developed in the first Cluster
- Multimedia training tools on biosecurity principles and measures made available to Canadian poultry producers
- Demonstration of several alternatives to traditional antimicrobials used in the poultry industry
- Information for the egg layer industry on the impact of genetics and management on productivity and general wellbeing of hens in alternative production systems
- Information for the broiler industry on strategies to monitor foot pad dermatitis and mitigate its effects
- Information for the turkey industry and development of best practices regarding stocking density in the production setting and management of conditions during live transport
- Further reductions of the environmental footprint of commercial poultry production
The 17 research activities will be conducted by 59 researchers from 24 organizations. These organizations include 11 universities (four international); five government departments (federal and provincial) representing both agriculture and human health; and eight companies involved in poultry research. Each research activity is led by a Principal Investigator from a Canadian university.
The Poultry Science Cluster provides capacity to resolve many current issues facing the poultry industry. The unique cooperation among scientists, industry partners and government departments across Canada will synergize efforts to address these issues. The scale of the Cluster allows for basic research and more near-term, applied studies that will provide both immediate answers and future information for the poultry and food industries, as well as factors impacting consumer wellbeing.
The membership of the CPRC consists of Chicken Farmers of Canada, Canadian Hatching Egg Producers, Turkey Farmers of Canada, Egg Farmers of Canada and the Canadian Poultry and Egg Processors’ Council. CPRC’s mission is to address its members’ needs through dynamic leadership in the creation and implementation of programs for poultry research in Canada, which may also include societal concerns.
February 26, 2014 - A three-year research agreement between Cobb-Vantress, Inc. and The Roslin Institute, at the University of Edinburgh, will facilitate collaboration on avian disease resistance, genome analysis and genome preservation.
Cobb, a global leader in poultry genetics, is putting almost $1 million into avian research programs at The Roslin Institute to identify innovative ways to improve avian health as well as developing unique technologies to understand and preserve the current and heritage poultry genomes.
The investment creates a strategic partnership between Cobb and The Roslin Institute that leverages each world class entity’s strengths. Mitch Abrahamsen, Cobb vice president of research and development, stated: “This research partnership provides a wonderful opportunity for Cobb to continue a close collaborative relationship with The Roslin Institute and their new National Avian Research Facility (NARF).
“The continued financial investments by The Roslin Institute in people and infrastructure demonstrate their commitment to making significant contributions toward improving poultry health and capitalizing on the opportunities afforded by the ever expanding understanding of the chicken genome.”
The National Avian Research Facility recently opened a state-of-the-art facility with its focus in poultry research. Professor David Hume, director of The Roslin Institute, said of the new agreement: “The joint partnership with Cobb is an excellent example of the kind of industrial interactions that allow The Roslin Institute’s research to drive sustainable improvements in animal health and livestock productivity."
One of the applications of this joint partnership is an effort to develop new technology enabling pedigree or heritage lines to be maintained without the need to physically maintain the bird stock. In addition, several projects will investigate DNA markers in the genome, targeting some of the more difficult to select for traits such as avian immunity, disease tolerance and disease resistance.
“These are exciting new areas which we hope will lead to major breakthroughs in avian health and preservation.” said Dr Christine Daugherty, chief technology officer of Cobb.
“Cobb has an extensive gene pool and to be able to better understand the poultry genome will be critical to meeting future demands for poultry products. We’re always striving to breed more robust chickens that will withstand disease and environmental challenges. We’re looking for birds with greater immunity to diseases or with the ability to tolerate disease without affecting their performance.”
The collaboration will support research by graduate students and is for an initial three years, with potential for renewal. The agreement with The Roslin Institute, which receives strategic funding from the Biotechnology and Biological Sciences Research Council, is one of more than 30 research projects that Cobb has been supporting in 18 different universities across the globe over the past five years.
February 18, 2014, Guelph, Ont. — Agriculture Minister Gerry Ritz today announced an investment of $4 million to the Canadian Poultry Research Council (CPRC).
The research will focus on helping the poultry processing industry remain competitive, while addressing consumer concerns about poultry welfare and environmental preservation. This will include developing new vaccines, finding viable alternatives to the use of dietary antibiotics in chicken production, reducing the environmental footprint of poultry farms and providing poultry farmers access to high-calibre training opportunities.
This investment builds on research funding previously received through AAFC’s Canadian Agri-Science Clusters Initiative as part of Growing Forward.This investment is made through the Industry-led Research and Development stream of AAFC’s AgriInnovation Program, a five-year, up to $698-million initiative under Growing Forward 2.
Roelef Meijer, chair of the Canadian Poultry Research Council says that Canada's poultry industry has made embracing innovation part of the industry's vision in recognition of the need to be dynamic and to foster efficiency for farmers and its industry partners.
"This announcement of funding for a second Poultry Science Cluster is a substantial contribution to the sector's future," he says. "It will enable researchers to find more immediate answers to industry issues and to provide important information to farmers, stakeholders and consumers."
January 24, 2014 — The Canadian Broiler Hatching Egg Producer's Association (CBHEPA) is offering a broiler breeder research grant to one or two university students to study and perform a short-term broiler breeder research project.
The research grant(s) will give third-year or graduate students the opportunity to perform broiler breeder research at a Canadian university or research facility on the following topics:
1. Production-based research
2. Food Safety
3. Control of Salmonella
4. Breeder welfare
5. Environmental Research
6. Poultry health and disease
7. Dark-meat utilization
Interested students must provide CBHEPA with a detailed description of the project, it's duration and location, potential benefits to the broiler hatching egg industry, reason support is needed and the budget of the project (including CBHEPA's contributions).
Application deadline is February 7, 2014.
En raison de l’évolution dans la production de dindon, plusieurs questions importantes demeuraient sans réponses. Les doigts étant essentiels à l’équilibre et la mobilité, comment les doigts raccourcis affectent-ils les dindons avec des poitrines considérablement plus volumineuses qu’il y a 30 ans? Maintenant que les ciseaux chirurgicaux et la cautérisation avec lame chaude ont été remplacés par le traitement des griffes par microondes de Nova-Tech Engineering, les dindons souffrent-ils moins du dégriffage?
La recherche s’est basée sur l’hypothèse que le dégriffage diminue les égratignures sur les carcasses, sans provoquer d’effets négatifs sur le bien-être des oiseaux ou leur productivité. L’impact du dégriffage a été mesuré sur la production (croissance, efficacité alimentaire et dommage à la carcasse) et le bien-être des oiseaux (longueur et variabilité des doigts, guérison des doigts, cote de démarche/posture et comportement). Hank Classen croit qu’il était nécessaire d’évaluer le bien-être animal autrement qu’en mesurant les dommages à la carcasse ou les taux de condamnation. Le dégriffage par microondes réduirait les infections bactériennes, mais la coupe pourrait-elle être trop grande?
Les expériences ont été menées sur des groupes de 32 dindes Hybrid Converter par parquet, de zéro à 15 semaines, et des groupes de 17 dindons Hybrid Converter par parquet, âgés de zéro à 20 semaines.
Deux traitements ont été comparés : aucun dégriffage et le dégriffage par microondes. Les oiseaux ont été élevés jusqu’à des âges plus avancés qu’habituellement au Canada, mais comparables aux pratiques ailleurs dans le monde.
Chez les dindes, après 15 semaines, il n’y avait aucune différence significative de poids entre celles traitées et non traitées. Par contre, après 20 semaines, les dindons qui n’avaient pas été dégriffés pesaient environ un demi-kilo de plus que ceux qui avaient été dégriffés.
En examinant le gain de poids tout au long de la croissance, on constate que les dindons traités et non traités suivent la même courbe pour les premiers 70 jours. Plus ils deviennent gros cependant, plus la différence s’accentue. « Ceci nous porte à croire que les dindons traités étaient en quelque sorte réticents à se rendre à la mangeoire », a indiqué Hank Classen.
Chez les dindes et les dindons, les oiseaux dégriffés ont consommé moins d’aliments de zéro à sept jours. D’après le Dr Classen, on peut en déduire qu’ils ont été affectés par le dégriffage.
Les dindons dégriffés se sont aussi moins nourris dans la période de 126 à 140 jours, confirmant l’hypothèse d’une réticence à s’alimenter qui freine l’atteinte du potentiel génétique.
Toutefois, comme la recherche antérieure l’a aussi démontré, le taux de conversion alimentaire n’a pas été affecté par le dégriffage. La mortalité a été plus élevée chez les oiseaux dégriffés, mais dans le cadre des expériences, la différence n’était pas significative statistiquement.
Il y a plutôt lieu de s’inquiéter d’une autre observation : le grand nombre de dindons dégriffés souffrant de rotation tibiale, une condition qu’on retrouve habituellement chez des oiseaux qui ont subi des dommages physiques à leurs jambes en raison d’une exposition à une surface glissante. Les chercheurs croient que l’absence de griffes sur une litière de paille pourrait être en cause.
La trouvaille la plus importante est liée aux égratignures. Chez les dindes, celles dégriffées affichaient une importante réduction d’égratignure des carcasses. Parmi les dindons, les groupes dégriffés et non dégriffés affichaient peu d’égratignures de carcasse. « à 20 semaines, ces dindons pèsent plus de 20 kilogrammes. Ce sont de gros oiseaux. Il est possible que ce soit leur grande taille qui réduise le potentiel d’égratignures », a suggéré Hank Classen.
Il s’avère que les oiseaux dégriffés avaient des doigts en moyenne 8 per cent plus courts. La repousse des doigts était très variable. Un examen de plus près a démontré qu’à 14 jours, la guérison était terminée. Dans trois échantillons sur quatre, des colonies de bactéries ont été trouvées, ce qui révèle que le traitement par microondes n’offre pas une barrière complète à l’entrée des bactéries. Dans l’ensemble, le traitement s’est avéré constant et efficace.
Les chercheurs ont été surpris de constater que lorsqu’encouragés à marcher, les dindes et les dindons ont démontré une bonne mobilité, en dépit de leur forte taille vers la fin du cycle. Cependant, pendant leur première semaine de vie, le niveau d’activité des oiseaux dégriffés était réduit. « Les effets du dégriffage étaient pratiquement partis rendu à la fin de la première semaine, rapporte Hank Classen. Ces effets étaient sensiblement moindres chez les dindes que chez les dindons, mais on en déduit qu’il y a probablement une sensation d’inconfort ou de douleur (chez les deux sexes). »
Puisque les doigts contiennent des nerfs capables d’émettre des signaux de douleur, la coupe des griffes par microondes provoque certainement de la douleur, explique Hank Classen. « Il n’y a aucun doute à l’effet que ces oiseaux ont besoin d’un peu plus d’attention après le traitement. »
Même si la recherche a été menée sur de petits lots dans des installations expérimentales, les conclusions sont pertinentes pour les éleveurs commerciaux.
Sur la base de leurs expériences, les chercheurs ne recommandent pas de dégriffer les dindons, surtout ceux qui sont élevés pour les plus gros calibres. Ils ont constaté de la douleur après le dégriffage, des gains de poids inférieurs en âge avancé et un plus grand nombre de rotations tibiales. Et surtout, les dindons qui n’avaient pas été dégriffés ne présentaient pas d’égratignures sur leurs carcasses. « Nous devons nous préoccuper des questions de bien-être, affirme Hank Classen. Pour les dindons suivis dans ces expériences, le dégriffage a plusieurs aspects négatifs et aucun aspect positif. »
Cette recherche a été commanditée par le Conseil de recherches avicoles du Canada, Agriculture et Agroalimentaire Canada et Lilydale.
Classen pointed out that existing research on toe trimming was rather outdated. “The genetics of these birds has dramatically changed since the 1970s and 1980s. The technology used to trim toes has also changed.”
Because of this significant evolution in turkey production, several important questions remained unanswered. With toes being important for balance and mobility, how do shorter toes affect birds with considerably more breast muscle than 30 years ago? Now that Nova-Tech Engineering’s Microwave Claw Processor has replaced surgical scissors or cauterizing hot blades, do birds suffer less from the toe trimming procedure?
Classen’s research was based on the hypothesis that toe trimming can decrease carcass scratching without negative effects on bird welfare. The effect of toe trimming was measured on production criteria (growth, feed efficiency and carcass damage) and bird welfare criteria (toe length and variability, toe healing, gait score/stance and behaviour).
Classen said there was a need to assess animal welfare other than by measuring carcass damage from scratching and condemnation. Treating toes using microwaves may reduce bacterial infection, but could the trimming be too severe?
The experiment was conducted on groups of 32 Hybrid Converter hens per pen, from zero to 15 weeks of age, and groups of 17 Hybrid Converter toms per pen, from zero to 20 weeks of age. Two treatments were compared – no toe trimming and toe trimming – using the Microwave Claw Processor. The birds were grown to ages older than what is common practice in Canada but comparable to world standards.
|Chart courtesy of University of Saskatchewan
There was no significant difference in body weight between treated and non-treated hens after 15 weeks. However, at 20 weeks, untreated toms did weigh around half a kilogram more than treated ones.
A closer look at body weight gain over time revealed that both treated and untreated toms had comparable body weight gain for the first 70 days, but things changed as the birds got bigger. “This lends itself to the idea that the treated birds were somewhat reluctant to go to the feeder,” Classen said.
For both hens and toms, treated birds had a reduced feed intake from zero to seven days. According to Classen, this suggests that birds are affected by the treatment.
Treated toms also had a reduced feed intake at 126 to 140 days, confirming the hypothesis that there is a reluctance to feed and grow to genetic potential.
However, in agreement with previous experiments, the overall feed to gain ratio seemed not to be affected by toe trimming. Mortality was higher with treated birds, but in the context of the experiments, the difference was not statistically significant.
Of much greater concern was the number of treated toms that by the age of three weeks had a rotated tibia, a condition that can be found in birds that suffer physical damage to their legs because they are exposed to slippery surfaces. In this case, researchers suspect the cause may be the absence of claws on straw bedding.
The experiment’s most interesting finding relates to scratching. With hens, a very significant reduction in carcass scratching was observed among treated birds. Among the toms, there was very little carcass scratching in both treated and non-treated groups. “At 20 weeks of age, those toms weigh more than 20 kilograms. They are big birds. It’s possibly their size alone that reduces the potential for scratching,” Classen said.
As for toe length, it turns out treated birds have toes that are about eight per cent shorter. Toe regrowth is very variable. A close look at toes shows that by 14 days, most of the healing is done. In three out of four samples, bacterial colonies were found in treated toes, suggesting the microwave treatment is probably not a complete barrier to bacteria entry. But overall, the treatment was found to be consistent and effective.
Researchers were surprised to find that when encouraged to walk, both hens and toms showed good mobility despite their large size. However, during the first week, treated birds did have a reduced activity level. “These effects were basically gone by the end of a week,” Classen said. “The effect was slightly less in hens than in toms, but the bottom line is that these birds probably experience some type of discomfort or pain.”
Because the toe is innervated (it has nerves that can send pain signals), there is undoubtedly pain caused when severing it with microwaves, Classen explained. “There is no question that these birds probably need a little additional care after the treatment.”
Although the research was conducted on a small flock in experimental infrastructures, conclusions may be relevant to commercial turkey breeders.
In the case of hens, toe trimming is recommended despite welfare issues early in life. Classen says that this is counterbalanced by reduced scratching.
Researchers recommend against toe trimming toms, especially those grown to heavier sizes. There was indication of pain after treatment, reduced growth at later ages and an increase in rotated tibia. Most importantly, untreated toms did not suffer more carcass scratches. “For toms observed in this experiment, we have negative things that add up, and nothing positive to counterbalance.”
This research was sponsored by the Canadian Poultry Research Council, Agriculture and Agri-Food Canada, and Lilydale.
Pea production is increasing in Western Canada and while the pea (Pisum sativum L.) is mainly produced as human food, there is the potential for surplus and feed grade pea to be used in poultry feed based on availability and price.
But how does pea perform for poultry?
“The nutrient profile of pea is suitable for most poultry production, but it is not used to its potential because of incomplete and variable poultry nutrient data,” states PhD candidate Salaheddin Ebsim in his doctoral thesis.
In his study, entitled Establishing the Nutritional Value of Pea as Affected by Feed Processing and Pea Cultivar for Poultry, Ebsim and his supervisor, Dr. Hank Classen, were curious to clarify the nutritional value of pea in poultry diets to maximize its utilization and possibly reduce the cost of poultry production.
“The nutritional evaluation of pea for poultry has been mostly investigated elsewhere, but under local conditions these data are not sufficient for accurate feed formulation,” writes Ebsim, noting that different pea cultivars and growing conditions may also affect the nutrient composition and availability of pea for poultry.
Starch is the main source of energy in poultry feed, and while pea seed has high starch content, the starch is different from that found in cereal grain. Pea starch is less accessible to digestive enzymes in the small intestine, making it digest slowly. In humans, this has been shown to be a good thing, but research on chickens is rare.
As Ebsim explains in his thesis, “The slowly digestible nature of pea starch has been suggested to have a unique nutritional value for poultry with evidence that the presence of slow degraded starch reduces the amino acid requirements of broilers and that a mixture of rapidly and slowly degraded starch improves broiler productivity in contrast to diets containing only rapidly digested starch.”
The three overall objectives of the research included studying the effect of various feed processing on nutrient digestibility of pea; the effect of the interaction between locally grown pea cultivar and feed processing on pea nutrient digestibility; and the impact of feeding pea to laying hens, broiler breeder hens and broilers.
Ebsim found that fine grinding and pelleting improved both pea energy and protein utilization and that this effect was much more pronounced than for classical feeds like barley, corn, and wheat cereal grains. Of note, all cultivars reacted to processing in the same way.
Using laboratory and animal testing, Ebsim further demonstrated that pea cultivar had an important impact on both the rate and extent of starch digestion and that these improvements resulted in differences in broiler performance. This suggests that cultivar selection has the potential to improve the nutritional value of pea for poultry and possibly other animals as well.
The third objective of the thesis involved feeding pea to various classes of poultry at relatively high levels. In both broiler and laying hen trials, Ebsim found little evidence that the effect of amino acid intake on bird performance depended on the level of slow digested starch from pea. However, in all chicken classes, the production response of birds fed pea was higher than expected based on their digestible nutrient content. The reason for this response still requires clarification.
Some of Ebsim’s most interesting research came from feeding pea to broiler breeders during the brooding and rearing period. In feed restricted broiler breeders, feeding pea reduced the postprandial blood glucose level and altered bird metabolism in a way that may reduce bird hunger. Broiler breeders are most often fed every other day during the brooding and rearing period and feed nutrients are stored for a short period of time after feeding (approximately 24 hours) as fat in the liver, and then utilized until the hens are fed again. In some cases, the liver nearly doubles in weight and then returns to its initial weight during this period. When birds were fed pea, liver weight increases were less than for birds fed a more conventional diet. This research suggests that feeding pea to broiler breeders may have beneficial metabolic effects, but research is required to confirm this.
Ebsim sees increased potential to include feeds such as peas to meet future production requirements. “The use of new grain or pulse cultivars with higher nutritional value will also see increased interest, particularly those that grow well in a wide range of environments,” he states. “Pea is a good candidate for further development in this regard as it can be grown in most of places in the world.”
The research received scholarship support from the University of Tripoli, Libya, as well as support from the Saskatchewan Pulse Growers and the staff and students at the Poultry Centre, University of Saskatchewan.
This new regular series of articles is part of the communications plan of the Poultry Welfare Centre. For more information, visit the Canadian Virtual Centre for Poultry Welfare at http://poultrywelfarecentre.ca/
The seminar was dubbed, The Triangle of Influence for Maximizing Profits. Genetics – Health- Nutrition, and featured presentations that examined the practical impact of genetic selection, diet, and preventive care has to the overall production potential in flocks.
"The strategic alliance between Aviagen, CEVA, and DSM in continuing customer education was exemplified in these two full days of collaboration featuring knowledgeable speakers and enthusiastic and engaged participants," said Canadian Regional Business Consultant for Aviagen Scott Gillingham.
The triangle of interaction between veterinarians, nutritionists, and production managers extends the reach of the innovative research and development programs of the primary breeder through ideas, knowledge, and communication in the field to maximize poultry health, welfare, and financial return.
The program featured in-depth and relevant presentations including:
- Breeding objectives and Selection Strategies for Broiler Production by Dr. Derek Emmerson , Aviagen, highlighted that annual improvements will continue with a diversity of breeds to meet market needs.
- Optimum Vitamin Nutrition for Poultry, Dr. Marc deBeer, DSM Nutritional Products, emphasized the need to revisit vitamin and mineral levels. Vitamin levels have a dramatic effect on FCR and yield gains.
- The Future in Vectored Vaccines, Dr. Christophe Cazaban, CEVA, discussed how vector vaccines optimize vaccine take and improve safety.
- Coccidiosis: The Never Ending Story, Kobus VanHeerden, CEVA, discussed the improvements and importance of good coccidiosis control.
- Poultry Feed Enzymes: Where are we?, Doug Teitge, DSM Nutritional Products, covered how enhancements in enzyme products promotes improvement of feed availability to the bird to meet the nutritional demands for growth and efficiency in poultry production.
Dr. Classen was named Distinguished Professor at the University of Saskatchewan in the spring of 2013 and within a month was also awarded the position of Industrial Research Chair in Poultry Nutrition, leading a five-year, $3.6-million National Sciences and Engineering Research Council (NSERC) research project.
Such an honour hadn’t even dawned on the early teenager when he was tending the chickens, turkeys, ducks and geese for a neighbour, Mrs. Ryba, a quarter mile down the road from his family’s grain and pig farm. It was a key time of influence on the young boy: he discovered poultry.
Classen did his early schooling in Aylsham and Nipawin, Sask., and then finished his last year of high school at Rosthern Junior College, a private Mennonite school. His family core values of hard work are typical of that era and that work ethic has had a strong impact on his life and what he thinks is important.
His father hoped that his youngest boy would pursue a career in banking. After all, his dad thought bankers must have a good life since banks were open only until 3 p.m. at that time. But much to his father’s chagrin, the young man ended up with a B.Sc. in agriculture from the University of Saskatchewan with a poultry science major.
“People can’t always understand where your interests will lead you,” says Classen, but he feels lucky to have loving family members who supported him even though their choices may not have been the same.
Classen’s mentor through his undergraduate degree, Roy Crawford, had done graduate work at the University of Massachusetts, so it was more than just coincidence that his own interest in research took him there as well. By then he was married with a year-old daughter and that’s when he and his young family left Saskatchewan for the first time. With a University of Saskatchewan jacket slung over one shoulder and a pony porta-potty for his little daughter slung over the other, he travelled with his family by bus and train to Massachusetts with all their worldly possessions in 23 boxes, including their pots and pans.
At the University of Massachusetts, Classen did two degrees under the supervision of his key mentor, J. Robert Smyth Jr. With his thesis written, he was quickly accepted for an assistant professor position at Pennsylvania State University, where he worked for one and a half years.
But when a professor at the University of Saskatchewan retired, Classen saw a chance to come home. His wife came with him for the interview but he didn’t tell anyone else, wanting to make the decision without outside pressure.
That’s when the phone in the hotel room rang – it was his Aunt Betty, welcoming him back to the province. “Within a half hour we realized there were no secrets in Saskatchewan,” he says. He was glad to be home. That was 1978.
It has now been 35 years since Classen returned home to Saskatchewan, and as he says, “I’m still here and having fun.”
For Classen, being appointed as Industrial Research Chair is “a big honour that the poultry industry had confidence in me and put a lot of money on the table to make this happen.”
Even the organizing committee questioned if his ambitious mandate meant he was biting off more than he could chew, but organizing 20 studies in poultry nutrition – with three undergraduate, five M.Sc. and four PhD students, two post-doctoral fellows and a professional research associate – while addressing the requirements of nine sponsors, will all follow a logical sequence of events. “It’s the way I like to do research,” says Classen, who expressed great confidence in his team and collaborators.
Funding for the five-year project has been provided through NSERC and poultry industry organizations in Saskatchewan, allowing Classen and his team to study starch and protein utilization in poultry and its potential to affect production, health and welfare.
With this award the University of Saskatchewan will also hire a new poultry scientist, which Classen says is important to the stakeholders in this research as well as to Canadian poultry science research in general.
The Alberta Livestock and Meat Agency Ltd. (ALMA) is working with a team of researchers to create a new vaccine for poultry to help prevent the spread and damage that two pathogens cause to poultry producers – Salmonella and Clostridium perfringens.
Dr. Christine Szymanski, a University of Alberta professor and one of the researchers involved in the project, said that the preferred method of control for these two pathogens would be a vaccine, as it can help reduce the risk of contamination of eggs and meat without the use of antibiotics. This is especially important due to the concerns from both consumers and producers regarding antibiotic resistance.
The researchers decided on Salmonella because of its ability to cause foodborne illnesses in humans, and Clostridium perfringens, which causes necrotic enteritis in broilers in addition to food poisoning in humans.
“While C. perfringens is the most common and financially devastating bacterial disease in commercial flocks, no effective chicken vaccine is commercially available,” said Szymanski. “And salmonella in humans is caused by consumption of contaminated eggs and poultry products, and results in potentially severe gastrointestinal issues.”
MAKING IT STICK
The vaccine research is based on Szymanski’s development of a successful carbohydrate-based poultry vaccine for another common foodborne pathogen, Campylobacter jejuni. This was accomplished through the use of bacterial glycomics, the investigation of sugars (also known as glycans), especially those found on the surface of the bacteria.
According to Szymanski, the sugars on the surface of pathogenic Salmonella and C. perfringens can be presented on the surface of a non-pathogenic bacteria, which means that a vaccine could be used to stimulate an immune response without the use of the deadly strains.
“This means we can create a vaccine from harmless bacterial strains that will help the bird’s immune system identify and destroy the pathogenic strains. In this way, a single vaccine will simulate an immune response in the bird that will protect it from a broad array of Salmonella and C. perfringens strains.”
She added that combining the two vaccines into one would provide an inexpensive vaccine against the two problematic pathogens. In doing so, this could eliminate the need for antibiotics for both diseases.
This is especially important for C. perfringens, Szymanski said, which currently can only be controlled through the addition of antibiotics into the drinking water.
AN IMPORTANT STEP
Glycan-based vaccines are not new, as human glycoconjugate vaccines have been routinely used for less than 20 years with minimal side-effects, and are routinely given to infants. Similarly, no side-effects have been seen with the C. jejuni chicken vaccine, and the live non-pathogenic organisms in the vaccine are only in the system long enough to induce an immune response before being cleared from the chicken entirely.
“Right now, researchers struggle to obtain a reproducible two-log drop in campylobacter colonization from chickens,” said Szymanski. “In our studies, we reproducibly observe six to eight logs drop in campylobacter colonization – with many birds having undetectable levels of C. jejuni in their intestines.”
Dr. Susan Novak, ALMA’s research manager, said, “A glycan-based vaccine would be a transformative advancement for the poultry industry. The use of antibiotics could be reduced if producers are able to give their birds a dual vaccine that boosts the immunity against multiple strains with a single shot. Alberta is leading the world in this area and that is a point of pride for our industry as well as a real competitive edge.”
In addition, Drs. Szymanski and Mario Feldman have spun off a company, VaxAlta Inc. in Edmonton that builds on their studies in bacterial glycomics. They were the first to identify the C. jejuni glycan pathway and show that sugar systems can be mixed and matched to produce novel glycoconjugates. Szymanski and Feldman are now exploiting this expertise toward the development of novel glycoconjugate vaccines for use in agriculture.
“The next step in our research is to optimize the carbohydrate-based vaccine against C. jejuni and create an effective dual vaccine against Salmonella and Clostridium perfringens. Glycoconjugate vaccines against other pathogens found in poultry, cattle and pigs are also in the pipeline,” said Szymanski.
Today, two breeders dominate the international market for layers, broilers (90 per cent) and turkeys. As well, there are hardly any middle-level breeders left in Canada, and until recently, five Canadian institutions conducting agricultural research kept 38 populations of chickens and Japanese quail.
The Pacific Agri-Food Research Centre in Agassiz, B.C,, has recently terminated its poultry unit, including nine lines of chickens and nine lines of Japanese quail.
It is clear that avian researchers and the poultry industry have experienced a massive loss of genetic resources. Maintaining live flocks is impractical and very costly, and economical methods of preserving poultry genetics for future use are badly needed, as genetic resources continue to narrow.
In the recent past, the only effective method of conserving poultry germplasm has been in living animals. Alternative options have been attempted over the years, but results have not been very promising. Fertility obtained from cryopreserved chicken semen is unpredictable and the structure of the avian egg prevents its cryopreservation. Embryonic cells can be stored and used to generate germline chimeras (organisms with a mixture of cells from different embryos), but this requires complex procedures and results in very low efficiency. Over the past century, chicken ovarian transplantation has been attempted with limited success.
Successful development of techniques for cryopreservation and transplantation of ovaries and testicles of birds can provide the means of maintaining the genetic variation needed for full differentiation of markets for poultry meat and eggs. Dr. Fred Silversides, formerly of Agriculture and Agri-Food Canada, together with Drs. Yonghong Song (Dubai), Jianan Liu (USDA post-doctoral research fellow) and Kim Cheng (UBC), has been working on optimizing cryopreservation and transplantation of avian gonadal tissue.
The first step in this research, which was Dr. Jianan Liu’s PhD project, was aimed at simplifying the storage process for cryopreserved genetic material by using vitrification, which converts liquid to a glass-like substance instead of ice crystals, and has several advantages over slow-freezing procedures in preserving tissue.
A vitrification protocol was developed to preserve Japanese quail ovarian and testicular tissue, using cryoprotective agents and acupuncture needles to facilitate tissue handling. Rather than using cryovials typically used for cryopreservation, a simpler straw system was tested and found to be an ideal storage medium, as it has the advantage of fitting into existing systems for storage and transport.
Normal morphology of testicular tissue was observed after in ovo culture and live offspring were produced by performing surgical insemination directly into the hen’s oviduct with the extrusion of cryopreserved testicular tissue. Donor-derived offspring were also efficiently produced from cryopreserved and transplanted ovarian tissue.
Also, because gonadal transplantation is critical to functional recovery of cryopreserved tissue but can be limited by tissue rejection, the researchers used thymic tissue to improve the efficiency of immunological acceptance. Donor thymic tissue was implanted into recipient embryos, and gonadal tissue from the same donor was transplanted under the skin to the recipient after hatching. Transplant viability and histology were also examined.
It was found that thymic implantation might improve survival of gonadal transplants from chicken to chicken, but not transplants from quail to chickens. Investigations into avian ovarian transplantation led to intriguing additional observations: donor-derived offspring were produced from transplanted adult quail ovarian tissue, although delayed age at first egg and reduced reproductive longevity were observed with the transplants. As well, offspring with chimeric plumage coloration were produced from cryopreserved and transplanted chicken ovarian tissue, indicating chimeric folliculogenesis.
This project provides a successful model of cryobanking avian gonadal tissue using a simple vitrification method and suggests future directions in improving transplantation tolerance and using gonadal transplantation in avian research. This is good news for the poultry industry, as cryobanking of germplasm is both economical and ensures availability of genetic resources for years to come. To read more about this research project, please visit www.poultryindustrycouncil.ca.
The Poultry Industry Council congratulates Dr. Fred Silversides on his 2013 Poultry Science Association American Egg Board Research Award.
The American Egg Board Research Award is given to increase the interest in research pertaining to egg science technology or marketing that has a bearing on egg or spent hen utilization. The award is given to an author for a manuscript published in Poultry Science or The Journal of Applied Poultry Research during the preceding year.
James McIntosh earned both an undergraduate degree in 1959 and a master’s degree in 1961 (in poultry nutrition) from the university. “My years at the university were enjoyable, both as a time to learn and as a time to make lifelong friendships,” says McIntosh.
“The OAC is where I met Brenda, my wife and business partner, and the friendships I developed proved invaluable in my career in agriculture. Plus, being a graduate of OAC provided an immediate introduction and connection to others in the agricultural industry who graduated from the same school.”
The gift is significant in a number of ways, says OAC dean Rob Gordon. “In particular, it is so fantastic when some of our alumni are able to provide back to the institution,” says Gordon. “And certainly this McIntosh gift is a perfect example of an individual who is a graduate from our program who’s giving back, which we appreciate.”
Gordon says that the gift also allows the Animal Poultry Science department, as well as the Ontario Agricultural College, to continue to be recognized as leaders in supporting the poultry industry in Ontario, both nationally and internationally.
The major aspect of poultry production continues to be the cost, he says. As well, research on feed digestion and the absorption of nutrients will greatly help to improve the efficiency of the industry. Guelph hopes that the person who fills this position will work closely with the feed industry, as well as the various poultry organizations, to further create opportunities for innovation and improved efficiency.
The hiring process has already begun with the formation of a selection committee, and the university is currently consulting with industry organizations to put together a strategic plan, making sure they are all on the same page when it comes to the industry’s needs.
“We want to make sure that we attract the best candidates from all over the world for this position,” says Gordon.
The university expects that the position will be filled by the spring or summer of 2014. “We really feel the need to move forward as efficiently and effectively as possible, but at the same time want to make sure we find the right person,” he says.
It is expected that someone who is strongly focused on improving the feed efficiency and production capacity of the sector will fill the new professorship. “As part of that, they’re going to be looking for alternative feeds, improved feed use efficiencies, as well as other attributes that affect the whole context of nutrition,” says Gordon.
Michael Leslie, a poultry nutritionist with Masterfeeds, is thrilled about the news of the new professorship. He says in terms of available ingredients and production targets, Ontario’s poultry and feed industries are quite different from those in the United States, and even Western Canada.
“To have a professor at the university that is familiar with local conditions and able to help feed companies and producers meet our goals is much more valuable than importing talent periodically to try to find solutions to our problems,” says Leslie. “In addition, a local professor would keep on top of research going on across Canada and the rest of the world and be able to pass that knowledge along to our industry.”
Perhaps more important though, is the potential for the improved training of University of Guelph graduates. With the recent retirement of Dr. Steve Leeson, there’s some concern that Guelph graduates will have not acquired the necessary background in poultry nutrition through the Animal and Poultry Science Department, which means the industry would be hiring graduates who had no prior experience in poultry.
“This position will fill that gap and result in better trained, well-rounded graduates,” says Leslie.
“We really appreciate the McIntosh family for this transformational gift,” concludes Gordon. “It’s something that is allowing us to move forward during a time when the ability to hire new faculty at universities is often quite limited.”
First, probiotics are “good” bacteria given in dry inert form that are activated in the intestines of livestock and poultry. They implant, grow and change the ecology in a positive way by reducing pathogen populations within the animal. Probiotics have been shown to help birds cope with the stresses of day-to-day life in densely populated flocks, and can also be particularly beneficial in high-stress periods such as transport, drastic weather events or ration changes.
“Probiotics are multifaceted products with a variety of beneficial effects for chickens,” says Dr. Shayan Sharif, a professor in the Department of Pathobiology at the Ontario Veterinary College, University of Guelph. “Probiotic formulations have been shown to reduce the burden of pathogens in the chicken intestine, including Salmonella, Campylobacter, Clostridium and coccidia. In addition, probiotics can enhance immune competence of the bird, leading to better immune responses elicited by vaccines and also better resistance to infectious pathogens.” He adds, “In broilers, probiotics have been shown to be effective to increase growth performance and feed conversion, along with enhanced immune competence. In layers, probiotics also show positive effects on enhancing immune status as well as a positive impact on egg mass, egg weight and egg size.”
Sharif notes that because probiotics exert their effect through changes to the gastrointestinal microflora, they are most effective when given at an early age while digestive microflora is still being established. Therefore, there are generally different recommendations for broilers and layers.
There is not a lot of data on the use of probiotics in Canada, which Sharif thinks may be partly related to the required approval process. “I presume the use of probiotics in the European Union, South America, Asia and the U.S. is much more common,” he says.
“Based on an estimate by Lallemand (a Canadian company based in Quebec that researches, develops and produces yeasts, bacteria and related products), the probiotic market in 2009 was worth close to $600 million.” Other market analyses, he adds, reveal that among feed supplements, probiotics have the highest rate of growth of use.
Dr. Doug Korver also believes probiotics have a place in poultry production, but notes some technical and practical limitations. “The efficacy of probiotics is dependent on live bacteria being delivered to the digestive tract,” notes the associate professor in the Department of Poultry Nutrition at the University of Alberta, “[so] this makes issues such as shelf life, heat stability, compatibility with other ingredients very important.”
He also points out that simple probiotics, such as those with a few bacterial species, tend to be less effective than complex probiotics (which have many species), because a single bacterial species cannot always form a stable population. “The products I am aware of in Canada tend to be ‘simple’ probiotics, but I can’t comment specifically on the efficacy of any product,” he says. “There was a complex product available in the U.S. for a time, with about 29 bacterial species, I believe, but it stopped being produced a number of years ago because of the complexity of maintaining all of these species in continuous culture.”
Like Sharif, Korver thinks probiotics are likely most effective when given early in life, when the birds’ guts are more or less sterile. “In that case, a simple probiotic might be able to prevent colonization by a pathogen, even if it doesn’t stay over time,” he says. “It allows a ‘bridge’ between the naïve gut and the mature microflora the bird will have as it gets older.”
The beneficial probiotic bacteria are intended to occupy the surface of the intestine, and pathogenic bacteria are then unable to bind, which is necessary for colonization. “If they can’t bind, they get washed out with the fecal material,” Korver explains.
Like probiotics, phytogenic feed additives (PFAs) help prevent intestinal disorders and boost the health and growth rate of livestock and birds. These plant-derived products, which are mainly essential oils, can also improve feed intake by boosting palatability. PFAs have been shown to improve egg production, increase immunity in laying hens and broilers and provide beneficial effects on eggshell characteristics. Sharif says research has shown that carvacrol (from oregano) cinnamaldehyde (from cinnamon) and capsaicin (from chili peppers) can also improve the growth performance of poultry.
“The use of essential oils as feed additives for agricultural animals is gaining popularity,” he notes. “Essential oils are another possible alternative to antimicrobial growth promoters.”
Dr. Todd Applegate, a professor in the Department of Animal Sciences at Purdue University in Indiana, agrees. He points out that current estimates of PFA use in combined livestock/aquaculture/poultry diets in the European Union are around 20 per cent, and increasing.
“Phytogenic products certainly are discussed extensively within the U.S., but there is not nearly as much market penetration as in the EU,” Applegate says. “This may be due, in part, to the time which those products have been on the market and familiarity with cost/benefit. In contrast, the U.S. market has had a much longer history with probiotic products (since the 1980s), and thus there is more familiarity and somewhat better acceptance.”
Applegate notes that a PFA’s physiological effects vary depending on several factors, including which plant it comes from. “For example, some can be immune-stimulatory (for example, ginseng) versus others which can be immunosuppressive (like Ginko biloba),” he explains. “The physiologic effects that we have observed in our laboratory have been through changes to chemical composition of the mucus layer in the intestine.”
He adds that many of the PFAs on the market today contain blends of several plant extracts, and their benefits can vary due to the blend itself as well as the processes used to extract and retain the essential oils.
The effect of PFAs will also take some time, depending on their properties. “For example, if they impart an effect on changing the mucin production in the bird,” explains Applegate, “due to the time it takes to have a cellular effect on cell identity and processes, it could be upwards of a week before intestinal cells can completely ‘turn over’ and thus be completely influenced.”
Applegate says producers must keep in mind that each PFA and probiotic product on the market is very unique in terms of its specific attributes, and therefore neither should be considered as a “commodity” product. “For example, some have targeted specific pathogen reduction capacities, while others may have been selected for production traits of bacteriocins (antimicrobial compounds), adherence to the epithelial surface, longevity within the digestive tract, and/or production/use characteristics (thermal stability, chlorine resistance, etc.),” he notes.
Hopefully, much more Canadian research will be conducted on the effects, best use practices and detailed cost-effectiveness of PFAs and probiotics. In the meantime, interested growers should do their research and consult with trusted feed experts and nutritionists.
We would like to hear from growers who have had experience with these feed additives; please contact the editor.
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