Recently, there has been a significant increase in calls for the reduction or exclusion of in-feed antibiotics in North American poultry production. Notable restaurant chains and retailers, including McDonald’s and Costco, have publicly announced their intentions to eliminate the use of “medically important” antibiotics in their supply chains, prompting further announcements by major U.S. integrators, including Tyson, Pilgrim’s and Foster Farms to eliminate use of these antibiotics in their production systems in the coming years.
To be clear, while removing medically important disease prevention antibiotics such as bacitracin and virginiamycin, many of these companies are promoting the continued use of in-feed coccidiostats, parasiticides that control the intestinal parasites of Eimeria species.
The reason for these announcements, as noted in earlier articles in Canadian Poultry Magazine (October and December 2015 issues), is to address concerns over the development and transmission of antibiotic resistance to pathogenic bacteria in humans; so-called “superbugs”. While some continue to debate the contribution of animal agriculture’s use of antibiotics to the development of resistant bacteria in humans, as an industry, we have a responsibility to mitigate this risk where possible. This will support maintaining the effectiveness of the limited toolbox of antibiotics for treating human, as well as food production animal infections.
In order to maintain current levels of performance and health in our flocks we must find alternative feed additives or production strategies to replace these valuable tools. This story is not new. In fact, a ban on antibiotic growth-promotants (AGPs) was initiated in the EU in 2006. What is new is a rapidly growing North American demand for effective additives to replace antibiotics.
One of the concerns in antibiotic-free programs is the increased risk of necrotic enteritis (NE). Key antibiotics have claims for control of Clostridium perfringens (Cp), the causative agent in NE. New additives or feeding programs should offer some protection against Cp to help prevent NE outbreaks.
Feed companies are bombarded with products positioned as alternatives to traditional medicated feed programs, with numerous modes of action (how they work). A dominant category of these additives are essential oil or plant-derived extracts, registered largely as flavours, with anecdotal reports of improved growth in chickens. Essential oils are also widely considered antibacterial and have been shown to directly inhibit growth of Cp in the lab. Other technologies include yeast byproducts, prebiotics, probiotics, short and medium chain fatty acids, various acidifiers and antioxidants, most of which are single bioactive products. The reality is there is no single additive that is as effective as a drug, nor as inexpensive – no “silver bullet”. Despite the plethora of antibiotic-alternative feed additives that are promoted, little, if any, data are available to support the performance of these products under production conditions similar to a medicated feed program.
Nutreco Canada (Shur-Gain and Landmark Feeds) believes that a combination product, which improves the immune system and integrity of the digestive tract while inhibiting pathogen growth and colonization in the digestive system, will provide the strongest protection. No single bioactive compound can address all of these modes of action.
This formed the basis of a succession of studies over many years in screening various individual bioactive compounds and commercial products both in the lab, and under disease challenge conditions at our research facilities in Canada to identify products that would best meet the combined mode of action approach at a reasonable cost. We also used the experiences of our European Nutreco colleagues subsequent to the antibiotic ban in Europe, to develop alternative feeding programs to test.
The culmination of this effort was a three-site multi-location controlled study (a total of 180 experimental pens) comparing the performance of five dietary feeding programs, all with the same coccidiostat program:
- Negative control (no antibiotic);
- Positive control (includes 55 ppm bacitracin methylene disalicylate, or BMD);
- Alternative program 1 (combination of products with ingredients that have indirect pathogen inhibition and improvements to intestinal integrity/health/microflora);
- Alternative program 2, which later became the Nobelo program (combination of products with ingredients that have indirect pathogen inhibition and improvements to intestinal integrity, health and microflora and immune systems competency); and
- Alternative program 3 (combination of products to support digestive and immune systems competency).
Under non-challenge research conditions we saw no differences in mortality, but we did see, as expected, a significant improvement in overall feed conversion when feeding BMD (two points lower). We also noted that Alternative programs 1 and 2 (Nobelo) had similar improvement in FCR as the medicated treatment (Fig. 1), while alternative program 3 had little benefit.
Overall average mortality was lower when using BMD (as expected), but we were excited to see that both alternative programs 1 and 2 also had significantly lower mortality compared to the non-medicated control (Fig. 2).
Pen-based studies alone are not sufficient to help producers make informed choices as to whether products will work under commercial conditions. Our next step was to validate the performance of the alternative program 2 (branded as Nobelo and selected over alternative program 1 due to its lower cost) under field conditions. We repeated the field validation in two separate regions using different in-feed antibiotics with 38 commercial flocks in Quebec (19 flocks randomly assigned to antibiotic and 19 to Nobelo) and 20 commercial flocks in Ontario (10 flocks randomly assigned to antibiotic and 10 to Nobelo) in the fall of 2011. Under real-life commercial production conditions we saw no significant differences in average market weights, feed conversion or mortality in either region (Fig. 3), nor did we see any differences in production costs for antibiotic versus Nobelo.
Shur-Gain and Landmark feeds introduced the Nobelo feeding program in 2014, resulting in a 33 per cent reduction in our in-feed antibiotic use in broilers, with no difference in production performance when compared to flocks placed before or after Nobelo (Fig. 4a and Fig. 4b.).
What does all of this mean? It shows that producing poultry without feeding the birds medically important antibiotics is possible in a safe and economically sustainable way while maintaining performance. Perhaps most importantly, using this Nobelo strategy will help safeguard the use of our limited supply of antibiotics for when they are truly needed for disease treatment.
March 10, 2016 -A&W Food Services of Canada Inc. has announced a major commitment to become the first national quick service restaurant in Canada to serve eggs from hens raised in better cage-free housing. According to a company press release, the company expects to achieve this goal within two years. "A&W has already established its leadership role by being the first and only quick service restaurant chain to serve eggs from hens in enriched housing and raised without the use of antibiotics," the company said. "Currently, there are no open barn housing options available that meet A&W's supply needs and allow for an antibiotic-free environment."
A&W is committing to improving and redesigning housing for egg laying hens, and will source eggs from hens raised without the use of antibiotics while simultaneously advancing the best practices for egg laying hens.
Furnished cages support behaviours such as scratching, perching and nesting, but their design continues to evolve. Thirty years ago, the earliest models held fewer than 15 hens and allowed them access to dust baths or litter. These prototypes presented problems with hygiene and egg collection, with scratch mats now being the norm. The size of the furnished cages has changed too – some of the newest models now house groups as large as 100 hens.
How does the performance and welfare of the hens respond to higher stocking densities?
A study done by Tina Widowski in the department of animal and poultry science at the University of Guelph, measured these parameters at two different densities in two different sized cages, with comparison to reference groups housed in conventional cages. The production parameters under consideration included feed intake, egg production, egg weight, mortality, body weight and body weight uniformity, feather condition, and bone strength.
“This research is some of the first ever to assess the welfare of hens housed in large furnished cages of different sizes and space allowances using measures of production, health and body condition,” said Widowski. “At any given space allowance hens in these larger groups have more total space available to them and more ‘free space’ since they tend to cluster together at different times of day leaving some parts of the cage largely unoccupied.”
Widowski used 1218 conventionally reared LSL-lite laying hens housed at the Arkell Research Station near Guelph, Ont. Eighteen-week old hens were individually weighed and wing banded before being placed in either larger standard commercial furnished cages or custom built smaller furnished cages.
The cages were populated with 80 (high density) or 55 (low density) birds in the larger cages and 40 or 28 birds in the smaller cages. This allowed for a stocking space allowance of either 520 cm2 ( approximately 80 in2, high density) or 748 cm2 (approximately 116 in2, low density) per hen. The European Union standard is 750 cm2/hen; a reference population in conventional cages was used for comparison at 465 cm2 (72 in2)/hen.
Furnishings included curtained nest boxes, claw shorteners, two linear feeders, nipple drinkers and a smooth plastic scratch mat where a small amount of feed (20g) was distributed several times per day. Perch allowances and nesting areas were proportionally sized for the cages and the hens were given feed and water ad libitum.
Egg quality was monitored continuously over the 50 weeks of the trial and egg quality was assessed every four weeks to provide an indication of shell strength. Hens were randomly selected for individual body weight measurements at 30, 50, 60 and 70 weeks of age, at which time they were also scored for overall cleanliness, feather condition, as well as keel, toe and foot damage health. At the end of the trial 10 per cent of the birds were assessed post-mortem for bone strength.
Overall the results indicate that most measures of productivity were not affected by the parameters of the trial. Hen day egg production, egg weight and eggshell deformation were not affected by cage size while there was slightly greater egg deformity (weaker shells) at 57 weeks of age in low space allowance.
Mortality was lower in conventional cages than any of the furnished cages (4.6 per cent vs. 2.0 per cent), unaffected by cage size. The majority of mortality occurred early in the study, due to injury or entrapment, while both birds and researchers adjusted to the new systems.
Feather condition deteriorated under all treatments over time, but hens in the high density furnished cages were poorer than the others, with the increased potential for abrasion by the furnishings or the possibility of increased feather pecking. This is supported by other research that found feather condition deteriorates with decreased space allowance.
Hens in large cages were the cleanest, possibly explained by cage design – the large cages were fitted with a wire partition over the scratch mat area that kept them from roosting and defecating there – or simply that higher density resulted in closer contact.
All bones were stronger in furnished cages than conventional cages, but leg bones tended to be weaker in the small cages with lower space allowance. Overall, space allowance and cage size had no effect on the rate of keel damage. Toe damage was higher in the furnished cages over conventional, possibly because the furnishings allowed greater opportunity for mechanical injury. Footpad damage increased significantly as space allowance decreased.
The only unexpected result was that hens in small furnished cages consumed significantly higher amounts of feed compared to large furnished cages, a result that Widowski explained may be due to the difficulty in gathering feed intake data and possibly greater feed wastage with this experimental design.
Widowski concluded that while productivity and mortality were not influenced by space allowance, the differences in feather condition and foot health might be a reflection of compromised welfare of hens housed at the lower space allowance. Given current research results of this study and a comparable research project at Michigan State University, she suggests a cage space allowance of at least 581 cm2 (90 in2) per hen would be considered appropriate for maintaining the physical measures of welfare quality specifically for the white laying hens used in this study.
This research was supported by OMAFRA and Egg Farmers of Canada with in-kind contribution of Farmer Automatic Cages from Clark AG Systems.
When it comes to developing a vaccine in response to emerging diseases that threaten the lives of animals, a pharmaceutical company needs to move quickly.
What it comes down to is being “first to know” and “fast to market”, said Dr. Raja Krishnan, formerly senior director of Swine and Poultry Research and Development for Zoetis and now of companion animal and equine biological research. Speaking to the Poultry Industry Council Health Day in Stratford, Ont., Krishnan put a global perspective on some of the corporate thought processes that precede his company’s decision to develop a vaccine.
Use of surveillance
“The world is becoming a smaller village,” said Krishnan. Zoetis, a leading pharmaceutical company with 10,000 employees in 120 countries, has access to global surveillance networks that use targeted regional surveillance to help guide rapid, high quality product development.
As an example, Krishnan called Avian Influenza (AI) a “disease that is travelling around the world, creating headaches.” With that kind of migration, how do we become proactive? How do we get ahead of the next round of disease? “It’s a decision that can’t wait,” said Krishnan. “Seasons change whether we’re ready or not,” leaving the company to do the right thing for their customers and the entire industry, sometimes making those decisions in a matter of minutes.
The AI outbreak affected over 48 million birds between December 2014 and June 2015. A lot of questions swirled around the decision to develop a vaccine; the disease was moving quickly. Did the industry want a vaccine? Would they use it? Would the government endorse it? Would the USDA recommend culling or vaccinating? Even if a product were developed, would it be relevant? Does it make sense?
Adding to this uncertainty is the fact that AI doesn’t play by the rules. The virus can mutate rapidly, meaning that the vaccine needs to be changed frequently. That’s one of the challenges. “AI constantly surprises us,” said Krishnan. “Nothing beats preparedness but we may have to course-correct collectively.”
When asked about the drivers behind the U.S. poultry industry deciding to use or not use the AI vaccine, Krishnan listed several of the questions such as, when will the product be available? Is there a risk of AI going into broilers as we go into the winter? Will this pressure us to act?
“Let’s not underestimate the economic and trade implications,” said Krishnan, what he called “the political aspects.” Will use of a vaccine result in trade restrictions? How does the issue get played out in the news? How does the consumer view the issue? What will the government do? How will pressure from retailers like Walmart affect vaccine use? He described the vaccination issue as “a jigsaw puzzle with so many uncertain parameters.”
Under a similar disease challenge in April 2013, Porcine Epidemic Diarrhea (PED) was identified in the United States; by September 2014, conditional vaccine licenses were being issued in the U.S. Everything happened rapidly, said Krishnan, fuelled by a commitment to U.S. pork producers and the veterinarians who support them to help contain an outbreak in 30 states that was responsible for the deaths of more than seven million piglets in the U.S..
What if their company goes down the wrong path? Krishnan admitted that sometimes a vaccine works in a test tube but falls apart in the real world; sometimes a disease doesn’t cause a problem, in which case the resources will be pulled back and re-invested.
With AI, are we headed in the right direction? Is it easier to cull the birds, clean up and move on? “That’s the million dollar question,” answered Krishnan. Thirty years from now we’ll have stories to tell.
February 17, 2016 – New research has shown that tackling antibiotic resistance on only one front is a waste of time because resistant genes are freely crossing environmental.
Analysis of historic soil archives dating back to 1923 has revealed a clear parallel between the appearance of antibiotic resistance in medicine and similar antibiotic resistant genes detected over time in agricultural soils treated with animal manure.
Collected in Denmark – where antibiotics were banned in agriculture from the 1990s for non-therapeutic use – the soil archives provide an 'antibiotic resistance timeline' that reflects resistant genes found in the environment and the evolution of the same types of antibiotic resistance in medicine.
Led by Newcastle University, UK, the study also showed that the repeated use of animal manure and antibiotic substitutes can increase the capacity of soil bacteria to mobilize, or ready themselves, and acquire resistance genes to new antibiotics.
Publishing their findings in the academic journal Scientific Reports, the study's authors say the data highlights the importance of reducing antibiotic use across all sectors if we are to reduce global antibiotic resistance.
"The observed bridge between clinical and agricultural antibiotic resistance means we are not going to solve the resistance problem just by reducing the number of antibiotics we prescribe in our GP clinics,” said lead author David Graham, professor of ecosystems engineering at Newcastle University.
"To reduce the global rise in resistance, we need to reduce use and improve antibiotic stewardship across all sectors. If this is not done, antibiotic resistance from imprudent sectors will cross-contaminate the whole system and we will quickly find ourselves in a situation where our antibiotics are no longer effective."
Antibiotics have been used in medicine since the 1930s, saving millions of lives. Two decades later, they were introduced into agricultural practices and Denmark was among the leaders in employing antibiotics to increase agricultural productivity and animal production.
However, a growing awareness of the antibiotic resistance crisis and continued debate over who and which activities are most responsible led to the EU calling for the use of antibiotics in non-therapeutic settings to be phased out and Denmark led the way.
The Askov Long-Term Experiment station in Denmark was originally set up in 1894 to study the role of animal manure versus inorganic fertilizers on soil fertility.
Analyzing the samples, the team – involving experts from Newcastle University, the University of Strathclyde and Aarhus University – were able to measure the relative abundance of specific β-lactam antibiotic resistant genes, which can confer resistance to a class of antibiotics that are of considerable medical importance.
Prior to 1960, the team found low levels of the genes in both the manured soil and that treated with inorganic fertilizer. However, by the mid 1970s, levels of selected β-lactam genes started to increase in the manured soils, with levels peaking in the mid 1980's. No increase or change was detected in the soil treated with inorganic fertilizer.
"We chose these resistant genes because their appearance and rapid increase in hospitals from 1963 to 1989 is well-documented," explains Professor Graham.
"By comparing the two timelines, we saw the appearance of each specific gene in the soil samples was consistent with the evolution of similar types of resistance in medicine. So the question now is not which came first, clinical or environmental resistance, but what do we do about it?"
Following the ban on non-therapeutic antibiotic use in Danish agriculture, farmers substituted metals for antibiotics, such as copper, and levels of the key β-lactam genes in the manured soils declined rapidly, reaching pre-industrialization levels by 2010.
However, at the same time the team measured a 10-fold rise in Class 1 Integrons. These are gene carrier and exchange molecules – transporters that allow bacteria to readily share genes, including resistance genes.
These findings suggest the application of manure and antibiotic substitutes, such as copper, may be 'priming' the soils, readying them for increased resistance transmission in the future.
"Once antibiotics were banned, operators substituted them with copper which has natural antibiotic properties," explains Professor Graham.
"More research is needed but our findings suggest that by substituting antibiotics for metals such as copper we may have increased the potential for resistance transmission.
"Unless we reduce use and improve stewardship across all sectors – environmental, clinical and agricultural – we don't stand a chance of reducing antibiotic resistance in the future."
January 19, 2016 - Feed innovations are set to tackle the sustainability file in 2016, as a changed regulatory landscape and broad swath of fresh advancements take hold for pigs, poultry and ruminants. The innovations cover efficiency, profitability, environmental footprint, animal health and welfare, and more.
The wave of modernization is propelled by new science, says Rob Patterson, Technical Director for Canadian Bio-Systems Inc. (CBS Inc.), which researches, develops and manufactures a range of new bio-based livestock feed supplements. Another driving force is shifting demand toward alternative supplements, as industry adapts to new rules for more limited and judicious use of traditional options such as antimicrobials.
“The story of feed innovation for animal agriculture is entering a distinct new chapter in 2016,” says Patterson. “Regulations have tightened dramatically and there is more scrutiny and expectations of on-farm practices across the board. But at the same time, there is strong reason for optimism. We are seeing the latest advancements take a major step forward, in line with today’s sustainability demands, to bring more options for feedmills, producers, nutritionists and others in industry, to get more efficiency and value from production systems.”
One of the most promising areas of advancement for the new year is "multi-carbohydrase" feed enzyme technology, says Dr. Bogdan Slominski, a leading feed technology researcher at the University of Manitoba and a pioneer in developing enzyme technology for animal agriculture. CBS Inc. has a long-standing partnership with Slominski’s program.
“Multi-carbohydrase is the forefront of enzyme technology today, leveraging our best knowledge from 30 years of research and development,” says Slominski. “The latest multi-carbohydrase formulations can now consistently produce substantial improvements in weight gain and feed efficiency. There’s a strong production benefit and also a strong environmental benefit.”
The multi-carbohydrase approach involves combining multiple unique enzyme strains that between them express multiple unique activities and therefore can breakdown a much larger portion of otherwise indigestible feed components. “It’s a game changer,” says Slominski. “This innovation, in my opinion, has the greatest potential among the feed supplement innovations we see today, to greatly improve the economics and sustainability of livestock production.”
Nucleotides are another standout example taking a leap forward for 2016. Though relatively new to the livestock feeding sector, nucleotides are widely recognized for their importance in human infant nutrition. “Now a growing body of research shows nucleotide formulations designed for livestock feed can deliver strong feed efficiency, growth promotion and health benefits, particularly for young animals,” says Patterson.
With the threat of mycotoxins rising in the industry consciousness, advancements that help safeguard feed quality and protect animal performance have also risen to the forefront. “We see growing demand for new options that offer an insurance policy and bring peace of mind,” says Patterson.
Also grabbing more of the spotlight in 2016 are specially designed yeast-based supplements that defend against stress loss and support animal welfare, offering unique value during critical times such as weaning or transport.
“These are just a few leading examples among many,” says Patterson. “It’s an exciting time of new options and choice in the feed business.”
Omega-3 polyunsaturated fatty acids (ω-3 PUFAs) play a fundamental role in the prevention of cardiovascular disease in humans. Health authorities advise people to consume Ώω-3-PUFAs, particularly the long chain (LC) ω-3 fatty acids eicosapentaenoic (EPA) and docosahexaenoic acid (DHA). Consumers’ preference favours whole foods to supplements, and chickens are ideal for efficient transfer of Ώω-3-PUFA from feed to product. Fish oil and marine algae oil are currently used to facilitate enrichment of eggs with LC Ώω-3 PUFA. However, these products are in high demand by various industries, leaving identification of alternate sources of LC Ώω-3 PUFA necessary to ensure sustainability of poultry product enrichment. A new approach to increase the LC Ώω-3-PUFA in poultry is to use a modified form of flaxseed plant, altered to express a high proportion of steriodonic acid (SDA). Table eggs can incorporate a higher proportion of LC ω-3-PUFA than muscles, and as laying hens are capable of depositing LC ω-3-PUFA into a saleable product with less product stability challenges, they were an excellent starting point for this research.
Dr. Doug Korver and his research team from the University of Alberta examined the potential of using SDA-enhanced flaxseed to substantially increase LC Ώω-3 fatty acids in table eggs. This approach examines the effectiveness of bypassing bioconversion of LNA by utilizing SDA-enhanced flaxseed. The goal of the project was to develop an effective SDA-enhanced flaxseed enrichment program and ensure that interactions with other dietary lipids did not interfere with SDA flax as an enrichment source.
Two main experiments were performed to examine the potential of including SDA-enhanced flaxseed oil in laying hens diets.
The first experiment compared the addition of SDA-enhanced flaxseed oil with conventional flaxseed oil in the diet. Additionally, it investigated the potential metabolic competition among fatty acid sources (including fish oil), and thus potential limitations of the enrichment process. Feed consumption, body weights, egg weights and egg traits were measured, and egg yolks were collected at regular intervals during the course of the 35 day experiment. On termination of the experiment, liver samples were collected to perform fatty acid analysis and ovary weight and follicle size were used to determine the reproductive status of the hens.
The second experiment tested the impact of feed form on the enrichment process of the LC Ώω-3 PUFAs in table eggs. This experiment compared ground SDA-enhanced flaxseed with extruded SDA-enhanced flaxseed along with addition of enzymes to increase digestibility. Egg weights were measured daily. Feed consumption and body weights were measured and egg yolks were collected at regular intervals during the course of the 35-day experiment. Eggs collected on day 34 were used to determine lipid stability and hence, an indicator of product quality and shelf life.
In experiment one, supplementation of experimental diets had no effect on feed intake, body weight, egg production and egg trait parameters. Egg yolks from hens fed a SDA-enhanced flaxseed diet showed a 1.5-fold increase in LC Ώω-3 PUFA compared with hens fed a conventional flaxseed diet (152 mg/egg vs. 110 mg/egg). Additionally, changing the ratio of fatty acid sources (corn, canola, fish oil, flaxseed, SDA-flaxseed) did not result in lipid competition for bioconversion enzymes. Therefore, SDA flax can be used to enrich table eggs with LC Ώω-3 fatty acid regardless of other dietary oil sources.
In experiment two, extrusion and enzyme addition had no effect on feed intake, body weight, egg production or egg trait parameters. Similarly, feed processing (including enzymes) did not significantly impact egg yolk fatty acid profiles, however, egg yolk levels of Ώω-3-PUFA were consistently higher in eggs from hens fed SDA-enhanced flaxseed compared to conventional flaxseed. In comparison to other eggs stored for 30 days at 4°C, SDA-enhanced flaxseed enriched eggs had a higher index of oxidation, suggesting additional antioxidant protection may be required in the diets of hens fed SDA-enhanced flaxseed to extend storage life of Ώω-3 fatty acid enriched eggs.
The results of this study show that inclusion of SDA-enhanced flaxseed oil in the diets of laying hens can increase the levels of LC Ώω-3 PUFA in eggs, providing an alternative to inclusion of fish oil.
The Next Steps
SDA-enriched flaxseed could be adopted by producers as an alternative to other sources of Ώω-3 PUFAs. Future studies will be done to determine the potential economic impact of the results obtained through cost benefit analysis and to improve the efficiency of Ώω-3 PUFA enrichment.
This research was funded by the Alberta Livestock and Meat Agency, the University of Alberta and Canadian Poultry Research Council (CPRC).
Held every four years, the World’s Poultry Congress is being held in Beijing Sept. 5 to 8, 2016. The Congresses are sponsored and supervised by the World’s Poultry Science Association (WPSA), and organized and operated by local WPSA branches. This year, the Congress is hosted by the China Branch at the China National Convention Centre, part of the Beijing Olympic Park. For complete details, check the Congress website www.wpc2016.cn.
The two most important components of the Congress are the Scientific Program and the Exhibition. The Scientific Program presents various subjects through Plenary Sessions with invited speakers, as well as submitted papers and posters. The scientific sessions are wide-ranging and cover every aspect of poultry science and the poultry industry. The WPSA has worked over the years to make congresses attractive to the widest possible range of visitors — not only to scientists and technologists, but anyone working in or for a supplier to the industry will find parts of the program of interest. Congresses also offer ideal opportunities for networking, making new contacts and forging new business and scientific relationships.
Contemporary issues like Biotechnology and Waste Management are included alongside more traditional areas such as Nutrition, Incubation, Health and Disease in this very comprehensive program. The Plenary sessions will consist of reviews of recent research, while the submitted papers will include original research and cutting edge science from around the world.
A number of years ago, WPSA entered into a relationship with the Network for Family Poultry Development, and this has led to the introduction of information on Small-scale Family Poultry Production. In many countries, the proportion of birds kept in industrial systems is much less than those kept in small flocks under “village” conditions. These flocks often provide much-needed protein for families, as well as modest income. Getting science to these flock owners has always been a challenge, and WPSA has helped by including the subject at the last several Congresses.
The Exhibition, an essential part of the Congress, is being run by the Dutch company VIV and is called VIVChina2016. It will run from September 6th to 8th and include exhibits relating not only to poultry, but also dairy, hogs and aquaculture. The venue for the Exhibition is the New China International Exhibition Centre, and the space available is 30,000 m2. It is not part of the Congress Centre but there will be frequent shuttle buses provided between the two locations. A subway connection is also available.
For Canadians going to the Congress, there will be the opportunity to see first hand the developments taking place in Chinese science and in its poultry industry. Like most other aspects of life in China, both the industry and the science world have undergone massive development over the past few years. When I toured China (sponsored by the US National Renderers Association) in the 1990’s, the poultry science community was quite small, but growing. Interestingly, at the end of my visit, I met Dr. Ning Yang, who is now Chairman of the 2016 Congress. Industry at that time was relatively primitive, but preparing for rapid expansion. So today, Canadians can expect to encounter a vibrant scientific community and a very modern industry.
As usual at World Congresses, there will be a wide-ranging social program; details are not yet available but are to be announced on the congress web site in January, 2016. The same applies to pre- and post-congress tours.
New data analysis has shown there is a genetic link between pendulous crop in turkeys and how well the birds convert feed. This means certain birds may be more predisposed towards developing pendulous crops given their nutrition, management, environments, or combination of these.
This type of correlation is not uncommon in genetics when breeding for certain traits, and geneticists work hard to find balance between desired traits and resulting effects in other areas.
A pendulous crop is a pouch that hangs down lower than it should in poultry and becomes filled with feed and water that the bird can’t digest. Birds suffering from this condition will slow their growth and in some instances can become emaciated.
“Our research was aimed at determining what, if any, genetic relationship there might be between feed efficiency and pendulous crop in turkey, and if there was, whether we might be able to correct for this in a breeding program,” says Owen Willems of Hybrid Turkeys – the company behind the research.
“Avoiding pendulous crops in the turkey population is important to having an economically successful flock, as there is no recovery from this affliction,” he adds.
Researchers at Hybrid Turkeys examined eight years of data from their Ontario-based turkey breeding program in both a sire and dam line to come to their conclusions.
They discovered a small genetic relationship between pendulous crops and feed efficiency in the sire line, which over time, could cause a slight increase in occurrence of pendulous crop as the feed conversion ratios are improved through the breeding program.
In the dam line, however, there was no link, which shows that feed efficiency can be improved through that avenue without increasing the risk of pendulous crop.
Researchers concluded that the correlations between pendulous crop and feed efficiency traits show that pendulous crop should be included in the selection index whenever a feed efficiency trait is also included.
“Given the results of this work at Hybrid, we now have a clearer idea moving forward on how to decrease the incidence of pendulous crop in turkeys through genetic selection,” Willems says.
Pendulous crop is largely a seasonal problem, occurring particularly during hot weather, and is attributed to over-drinking and over-feeding or gorging.
To minimize the risk of birds developing pendulous crop, producers should:
- Make sure birds have access to clean, cool water at all times
- Sanitize drinkers regularly and monitor chlorine levels in the water
- Monitor water consumption to determine if turkeys are drinking more or less water than usual
- Maintain regular, consistent access to feed
- Ensure poults don’t become overheated. During brooding, room temperatures should be 29-33C
Visit www.hybridturkeys.com for additional information.
“Prevention is key here as there is no economically viable treatment available for pendulous crop,” Willems advises.
December 18, 2015 - Cranberry extracts, derived from the pulp of pressed berries, may be a promising, natural treatment to increase the life expectancy of young broiler chickens.
Healthier birds, with enhanced immunity from a natural source, could reduce production costs for farmers while meeting consumer demand for high-quality, antibiotic-free poultry products.
Dr. Moussa S. Diarra, a research scientist at Agriculture and Agri-Food Canada’s (AAFC) Guelph Research and Development Centre, is currently conducting trials to examine the effects of cranberry fruit extracts on the immunity of broiler birds during their first 14 days of life, a critical period when “they need something to build up their immunity” against infectious disease. “Young birds are fragile and can be hit by several types of infections” if preventive measures aren’t administered, he notes.
Cranberries have long been used in human nutrition and are reported to have various human health benefits because of their high antioxidant compounds and immune-boosting properties. “If they are good for humans, why aren’t they for other animals?” speculated Dr. Diarra.
“Results have shown that cranberry extracts could decrease mortality by 50% in the early life of broiler birds, when treated with 40 mg of cranberry extracts per 1 kg of feed.” - Dr. Moussa Diarra, Research Scientist, Guelph Research and Development Centre, Agriculture and Agri-Food Canada
Dr. Diarra is the first research scientist in Canada to study the benefits of cranberries on the immune systems of broiler chicks. Since cranberries “are already accepted in human consumption,” it may be possible to satisfy producers’ needs for cost-effective, benign methods to increase animal health by using a food by-product, he notes.
Dr. Diarra and his team conducted a research study of broiler growth performance that was jointly funded by AAFC and the Canadian Cranberry Growers Coalition. The team fed commercial cranberry fruit extracts, derived from cranberry juice, to 1,200 one-day-old male broiler chicks. The chicks were studied in a sanitary facility, where mortalities were examined in comparison with non-treated chicks for up to 35 days. The results have shown that “cranberry decreased mortality by half” in one-to-10-day-old birds, when treated with 40 mg of cranberry extracts per 1 kg of feed.
Dr. Diarra explains that increasing birds’ resistance to the colonization of pathogenic bacteria, such as Salmonella, while boosting overall birds’ immunity, can increase the sustainability of chicken production.
Currently, Dr. Diarra is leading a multidisciplinary team of scientists and farmers in British Columbia, Ontario, Quebec, and Prince Edward Island to examine whether extracts, derived from the cranberry fruit waste (pomace), can replace the use of antibiotics in the young broilers. Pomace is otherwise discarded after the berries are pressed, but, “we can use this by-product,” to develop extracts instead, he notes.
Additionally, the trials will look at meat quality, because the antioxidants in cranberries could help increase storage time. This is because antioxidants prevent the oxidation of molecules in the meat, maintaining freshness, Dr. Diarra explains.
The study speaks to greater issues in animal production, including the increasing need for viable alternatives to using antibiotics as growth promoters and increasing antibiotic resistance. The anticipated results could be advantageous for both producers and consumers.
The Guelph Research and Development Centre is part of AAFC’s network of 20 research centres across the country. Located in Guelph, Ontario, the Centre is committed to specialized research in the areas of food safety, quality and nutrition to ensure Canadian-produced food is the safest and highest quality in the world.
Key discoveries (benefits):
Cranberry extract helps prevent early mortality in 1-to-10-day-old broiler chicks.
Current studies suggest it is a viable immune-boosting agent that could reduce antibiotic usage.
The antioxidant properties of cranberries may help enhance chicken meat quality.
Like broilers, it is probable that daylength has an impact on both productivity and welfare in turkeys and therefore it is economically relevant to understand its consequences. Welfare issues seen in broiler research may be more pronounced in turkey production where age and bird size at market have changed considerably over the last decade. These changes likely mean new challenges for modern strains as previous research was performed some time ago on birds that did not grow as quickly or reach the same market body weights. The challenges include both bird productivity and welfare. However, research and literature are lacking on the effects of lighting programs on modern commercial turkeys.
M.Sc. student, Catherine Vermette, Dr. Hank Classen and the research team at the University of Saskatchewan aimed to determine the effect of graded levels of daylength on the welfare and productivity of modern commercial turkeys. A more complete understanding of lighting effects can be achieved by using graded levels of daylength to allow prediction of response criteria associated with productivity and welfare.
Productivity and welfare parameters assessed included growth, mortality, meat yield, behaviour, bird mobility and leg abnormalities, skin lesions and ocular measures. Productivity parameters assessed were not only economically relevant, but applicable to welfare when behaviour and bird health measures were incorporated. These measures together provide a description of welfare in turkeys. Results will provide scientific evidence for recommendations on lighting programs that are known to positively affect the welfare of turkeys and optimize productivity in Canadian flocks.
Four graded levels of daylength (14, 17, 20, and 23 hours) were used to raise male and female turkeys to 18 weeks of age. The research included two trials with two replications per trial. Each trial consisted of 4 lighting treatments with two room replications for each lighting program. Productivity and welfare parameters were assessed at regular intervals during the course of the trials.
This study’s findings show that daylength affected turkey productivity in an age and gender dependent manner and use of longer daylength during the production cycle of males and female turkeys also affected a number of other measures indicative of reduced welfare.
At young ages, growth rate increased with increasing daylength, although this was reversed in older birds, sooner in males than females. In terms of mortality, shorter daylength treatments had beneficial effects on older birds and had a more pronounced effect on males. Carcass characteristics were affected by daylength in an age, but not gender dependent manner. Furthermore, the incidence of culling was increased with 23 hour daylength regardless of gender or age.
In general, longer daylengths had negative welfare implications in regards to turkey health and behaviour for both genders, but with a more pronounced effect in males. Mobility decreased with longer daylength for both genders, but the proportion of birds with poorer mobility associated with pain was only evident in males. Similarly, the incidence of breast blisters increased with increasing daylength, only in males.
Lighting program recommendations derived from this research for meat turkeys are dependent on gender and the age at which birds are marketed. For both genders regardless of age beyond early brooding, 23 hours of daylength was found unacceptable due to reduced welfare, with birds experiencing poorer mobility, increased ocular size and increased mortality. In addition, for toms and older hens, the rationale for not recommending 23 hours daylength includes reduced growth rate.
For hens marketed at a younger age, a maximum of 20 hours of daylength is recommended, while the recommendation for older hens and toms is between 14-17 hours of daylength.
This research was funded by the Poultry Industry Council, Lilydale Inc., Charison’s Turkey Hatchery Ltd, and CPRC.
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.
Ontario now has a research study underway that will generate baseline information about the main pathogens – viruses, bacteria and parasites - present in non-commercial poultry flocks in the province.
Starting the first of October 2015 until the end of September 2017, small flock (non-quota, non-commercial) owners of chickens, turkeys, game fowl, geese and ducks, are encouraged to submit sick or dead birds to the Animal Health Laboratory in Guelph or Kemptville for post-mortem examination and diagnostic testing. Submissions must be made through a veterinarian, who will do the initial screening of submissions. While there will be some veterinary fees involved at the farm level the lab testing itself will be done at a substantially discounted cost of $25 per submission. The tests would normally cost over $500.
“In general, there is not a lot of data,” said Leonardo Susta, DVM. “The number of small poultry flocks has markedly increased over the past few years in Ontario, however, there is a void of knowledge regarding the type and number of diseases that affect this segment of the poultry sector.”
Susta, who works out of the Department of Pathobiology at the Ontario Veterinary College, is leading this effort and is providing some of his own research funding to hire a graduate student for this project. Funding for the tests is provided by the Animal Health Laboratory (AHL) within the framework of the Ontario Animal Health Network within the Disease Surveillance Program.
Susta said there isn’t a lower limit on the size of the flock, with the upper limit of less than 50 turkeys, less than 300 broilers, less than 100 layers or 300 or fewer ducks, geese and game birds. Pigeons and doves are excluded from this study.
Through a brief questionnaire, researchers will gather information about common husbandry and biosecurity practices used by non-commercial flock owners. The data collected may help to identify diseases that are specific to the non-commercial poultry population, while helping vets better understand the needs of these flocks and producers. The results will be also tied with current surveillance studies at the Ontario Veterinary College (see page XX).
“We want vets to know and encourage owners (to submit birds),” Susta told a meeting of the Poultry Industry Council in August. He will also be advertising the program through the distribution of flyers at shows and through hatcheries.
Partners in the study include the Ontario Ministry of Agriculture and Food, the University of Guelph, the Animal Health Laboratory and the Ontario Animal Health Network (Disease Surveillance Program).
For more information, visit:
December 1, 2015 - Research underway at Ottawa’s Carleton University may make it easier and cheaper to detect toxins created by mold. Called mycotoxins, they’re found in everything from grains to fruit and can cause illness and even death in both humans and animals.
A mold called fusarium that can occur in wheat and corn is a particular problem for farmers as it impacts the quality of their crop and the price they can receive for that crop - contaminated grain or corn isn’t suitable for animal feed or human consumption, so it is rejected by buyers.
“Mycotoxins are produced by fungi found in crops and food. They’re very robust and can survive processing, so we need a cheap and reliable test to detect them,” explains Dr. Maria DeRosa, a professor of chemistry at Carleton who is leading the research.
She has been working with Dr. Art Schaafsma of the University of Guelph Ridgetown Campus and Dr. David Miller at Carleton to develop a small test strip that will glow in the presence of mycotoxins when illuminated with a handheld UV light.
The device uses aptamers that DeRosa and her team have identified, which are small, single-stranded nucleic acids that can bind to large or small target molecules – in this case, mycotoxins.
“It’s a simple spot of nanoparticles on paper, a test that can be done on the spot at the grain elevator,” says DeRosa, adding the device can currently detect quantities as minute as 40 parts per billion.
Farmers are doing their part to prevent fusarium, such as monitoring temperature and moisture levels in their fields to predict when their crops might be at risk for developing the mold and deciding when to apply fungicides, but the mold continues to pose a challenge.
Current mycotoxin testing methods at Canada’s network of grain elevators – where farmers take their crops to market – involve both a visual inspection and taking and analysing a random sample from a load of grain or corn.
Not only is this time consuming and expensive (each test can cost between $50-80), but it is also far from accurate: taking samples from different parts of a single load of grain can yield very different results.
Aptamers can be made in a lab very uniformly and at a low cost compared to the mouse antibodies used in current available tests, which means they’ll provide accurate and consistent test results without great expense.
“The needle-in-the-haystack nature of the current sampling process is the problem that we’re trying to address,” says DeRosa, adding that the sheer volume of grain and corn produced in Canada means a testing method also has to be quick and cheap.
After early successes in the lab, her team’s next step is to now move testing of the new technology to a larger scale beyond the lab and into a commercial setting.
Agricultural operations contribute to the atmospheric burden of pollutants, mainly in the form of ammonia (NH3), particulate matter (PM) and greenhouse gases (CH4 and NO2). Poultry operations are major emitters of PM and NH3 whereas other pollutants are emitted to a lesser degree. Much still remains unknown about the variability in the emissions of pollutants.
Additional issues are evident with PM that relate to its composition, toxicity and pathogenicity. PM2.5 are typically secondary particles formed by the reactions of specific gaseous pollutants that create fine airborne salts and liquid aerosols. Secondary inorganic aerosol (SIA) formation chemistry typically involves NH3 as an alkaline precursor gas. As NH3 is produced in poultry houses, SIA particles may be partly responsible for the high PM2.5 levels observed. Thus, if SIA are being formed, it may be feasible to reduce the toxic PM2.5 levels in the house by targeting gaseous NH3 and/or the other reactive gases directly with control methods and thus reduce exposure to both poultry and barn workers.
Dr. Bill Van Heyst and his team from the University of Guelph’s School of Engineering conducted a study to determine some of the impacts poultry production has on our environment.
The study investigated the indoor concentrations and emissions to the atmosphere of a variety of air contaminants from different poultry production systems. Measurements included:
- Air emissions from poultry housing units
- Air emissions from litter storage facilities
- Ammonia emissions from land application of litter
- Assessment of nitrogen loss via emissions from deadstock composting
The overall objective of this project was to provide a sound scientific knowledge base regarding actual agricultural air emissions. Contaminants focused on included: size fractionated particulate matter (PM), NH3, SIA concentrations and emissions as well as that for CH4 and non-methane volatile organic compounds, sulfur dioxide and other
Air emissions from poultry housing units:
a) Broiler and Layer facilities
Actual pollutant emissions were determined for broiler chicken (NH3, PM2.5, PM10 and CH4), layer hen (NH3 and PM2.5 and PM10), and turkey grow-out (NH3 and PM2.5 and PM10) housing units
NH3 and PM10 emissions peaked during the winter months, while PM2.5 emissions peaked during the summer months in the layer hen facility
b) Efficacy of a sprinkler system to control NH3 and PM levels
Use of a sprinkler system reduced pollutant emissions more so for PM10 and PM2.5 than NH3 emissions.
c) Effectiveness of Poultry Litter Treatment (PLT) application Poultry litter treatments reduced ammonia emissions
Measurement of air emissions from litter/manure storage facilities:
a) Broiler litter storage facilities emit more CH4 than that from cattle manure but less than liquid swine manure storage facilities.
b) Broiler litter storage facilities emit more N2O than that from cattle manure and liquid swine manure storage facilities.
Measurement of air emissions from land application of manure/litter:
a) NH3 losses from the broadcasted broiler manure were found to be 22 per cent and 25 per cent of the NH4-N applied after 72 and 132 hours respectively.
Measurement of nitrogen loss via ammonia emissions from deadstock composting
a) The NH3 emissions for piles using poultry litter were greater than that of the control (wood chips) and the finished/mature poultry compost, whereas the CH4 emissions were the lowest.
Dr. Van Heyst’s research was supported by the Natural Sciences and Engineering Research Council of Canada, Poultry Industry Council and CPRC.
Aviagen Inc. renewed its Research Sponsorship for 2015. CPRC appreciates Aviagen’s continued support of poultry research through the Research Sponsorship Program (www.cp-rc.ca). Aviagen funds have helped support more than $8 million in poultry-related research through both CPRC’s annual funding call and as part of the Poultry Science Cluster since 2012.
November 19, 2015 - UC Davis today unveiled its new Pastured Poultry Farm, home to 150 young laying chickens and a living laboratory where students and researchers hope to develop innovative solutions benefiting pasture-based poultry farms, integrative crop-and-poultry farms, and backyard flocks.
Pasture-based chicken production offers many benefits as well as some challenges in terms of food safety, animal health and welfare, and environmental impacts, said Maurice Pitesky, a Cooperative Extension poultry specialist with the School of Veterinary Medicine and co-leader of the poultry project.
The new 4.5-acre farm, located about one mile west of the central UC Davis campus, includes a seeded, irrigated pasture, where the chickens can forage, as well as a bright red, student-built Eggmobile for protection and overnight housing. The pasture uses a portable electronic fence to protect against predators and is surrounded by a 50-foot band of uncultivated land to serve as a wildlife buffer.
"This is a unique innovation, research and outreach resource for the Western United States," Pitesky said. "The project includes faculty and students with expertise in veterinary medicine, husbandry, welfare, pasture management and engineering, which allows us to address issues related to predator control, welfare, food safety and food efficiency."
Debbie Niemeier, professor in the Department of Civil and Environmental Engineering, and her team have already developed a number of innovations for the project, including a tarp-pulley system, portable-shade and predator-mitigation structures, an automatic watering system, and modular roll-out nest boxes.
New solutions for changing times
"The poultry industry is going through significant changes in how poultry products are produced -- including the manner in which the birds are housed," Pitesky said, noting that one of the nontraditional methods gaining in popularity is pastured production.
One of the advantages of the pasture-based system is the opportunity for a farmer to integrate chicken production with a farm's existing cropping system, with the chickens providing natural fertilizer for the crops.
"It's also a way for crop farmers to move into poultry production without expanding their land or adding nitrogen fertilizer to their farming system," Pitesky said.
Students driving demonstration project
Pitesky is quick to point out that the new project is largely driven by students, who designed and constructed the red and white Eggmobile -- a mini chicken-barn on wheels. The mobile barn includes 32 nest boxes, each capable of accommodating several chickens. It can be moved to different locations in the pasture, gradually fertilizing the grass with chicken droppings as it goes.
Students also seeded the pasture, developed and installed a pasture irrigation system, and have been caring for the young chickens since they arrived in early October as day-old chicks.
The student and faculty research teams will be delving into issues involving diseases and chicken health, predation by wildlife, and occupational health for workers.
Participating students are drawn from the School of Veterinary Medicine, College of Engineering, and College of Agricultural and Environmental Sciences.
Eggs for the community
Eggs produced by the project's flock will initially be donated to food shelters. The potential for eventual egg sales to the community is being explored.
"We really want this to be a local and regional demonstration project," Pitesky said, noting that producers and community members are welcome to stop by and view the project and will be invited to future educational events at the site.
Eventually, the research team hopes to construct multiple Eggmobiles with different designs, in order to optimize cost, ergonomics and sustainability. And in time, the researchers would like to expand the project to include broiler chickens as well as cropping systems that integrate poultry, in order to fully maximize the potential of the land for food production.
Funding the project
The Pastured Poultry Project received $40,000 in startup funding from UC Agriculture and Natural Resources.
In addition, several stakeholder organizations have contributed a total of nearly $20,000 and donated feed, birds and equipment. A list of donors and other information about the UC Davis Pastured Poultry Farm can be found at:http://bit.ly/1O0qCv2
Despite routine utilization of standard vaccination protocols in broiler breeder and broiler flocks, outbreaks of diseases in broiler flocks still occur. However, limited data on pathogen prevalence and associated risk factors among commercial broiler flocks in Canada are available.
Dr. Michele Guerin, a Poultry Epidemiologist from the University of Guelph recently completed a comprehensive project that investigated the prevalence of nine viruses * and four bacteria of health significance for the Ontario broiler industry. The study included the associations of exposure to the pathogens with management and biosecurity practices, flock mortality, and condemnations.
“As a contribution to disease control initiatives, this study will enable producers to adopt better strategies to reduce the incidence of these pathogens within their flocks,” said Dr. Guerin in an interview.
Guerin’s team investigated 231 randomly selected Ontario broiler flocks and results showed frequent exposure to AAAV, ARV, CAV, pathogenic FAdV species, IBDV, Clostridium perfringens, and Enterococcus cecorum, and no exposure to, or low prevalence of, AEV, IBV, ILTV, NDV, Brachyspira spp., and Clostridium difficile.
Beyond prevalence, the genotypes of several of these pathogens were determined.
“Potentially pathogenic genotypes of FAdV, IBDV, and IBV were identified that can guide vaccine development and disease control efforts in Ontario,” she explains.
Although no specific management or biosecurity practice was identified as a predictor of all pathogens investigated, several factors were significantly associated with the prevalence of more than one pathogen (e.g. feed, barn and environmental conditions, hatchery, manure disposal, and antimicrobial use).
“Geographic and seasonal variation in the prevalence of a number of pathogens was evident,” Dr. Guerin indicated. “However no one district or season stood out as being a hot-spot or time period of high prevalence for all pathogens investigated.”
Of interest, a high proportion of Clostridium perfringens isolates were found to be resistant to antimicrobials commonly used in feed, and use of these antimicrobials was a risk factor in the development of resistance.
“Finding alternatives to the use of antimicrobials in the feed to prevent necrotic enteritis should continue to be a priority for the industry,” Dr. Guerin asserted.
Dr. Guerin highlights that of all the pathogens surveyed, only Clostridium difficile poses a potential risk of infection for humans via the food chain, and despite the fact that toxigenic strains were found among the isolates, the proportion of positive flocks was low.
This research was funded by the Animal Health Laboratory’s AHSI, Poultry Industry Council, OMAFRA- U of G Partnership, and Chicken Farmers of Ontario.
*Avian adeno-associated virus (AAAV), Avian encephalomyelitis virus (AEV), Avian reovirus (ARV), Chicken anemia virus (CAV), Fowl adenovirus (FAdV), Infectious bronchitis virus (IBV), Infectious bursal disease virus (IBDV), Infectious laryngotracheitis virus (ILTV), Newcastle disease virus (NDV).
Canada’s Inter-Agency Wild Bird Influenza Survey has been testing wild birds for the AI virus since 2005
The 2015 Avian Influenza outbreak was the largest animal health event in U.S. history, affecting 48 million commercial birds at 223 farms in 15 states over six months. North of the border the outbreak affected 245,600 birds across Canada, at 11 farms in BC, three in Ontario.
But it was minus forty degrees when the AI virus first appeared in poultry flocks in the Midwest U.S. How did the wild birds interact with the poultry in that extreme cold? Are the wild birds really to blame?
While the experts still shake their heads about the reasons why the outbreak got out of control or even got started, Jane Parmley, Epidemiologist with the Canadian Wildlife Health Cooperative (CWHC), continues to investigate the role of wild birds in the spread of the Avian Influenza (AI) virus.
Parmley has been part of Canada’s Inter-Agency Wild Bird Influenza Survey coordinated by the CWHC since 2005. From 2005 through 2014, over 50,000 wild birds have been tested for the AI virus in Canada. The first screening determines if the birds carry AI of any type. Positive birds are then further tested for H5 or H7 specifically; further positive tests then lead to investigation of the origin and pathogenicity of the AI virus.
Does the detection of low pathogenic AI in wild birds indicate a risk to domestic poultry? “We tend to blame wild birds when we don’t have an easy explanation,” Parmley told delegates at a Poultry Industry Council Health Day in Stratford, Ont., but would early detection of the AI virus in wild birds could provide a sentinel to poultry producers?
It’s a global story: the high pathogenic H5N8 strain was originally identified in South Korea in 2014, showing similarities to a virus detected in 2014 in China, eventually reaching birds in Russia, North America, Europe and Japan. There were three HPAI virus strains seen in North America in 2014/15: H5N8 Eurasian lineage, H5N1 and H5N2. It is believed that the North American viruses came across the Pacific because of their closer similarity to the Asian strain than the European strain, and the timing of arrival made more sense, said Parmley. So far the virus is not considered zoonotic, but that could shift quickly.
Wild birds that are considered as natural reservoirs of low pathogenicity strains include waterfowl (ducks, geese and swans), and shorebirds (such as waders and gulls). There are four flyways across North America – the Pacific, Central, Mississippi and Atlantic – connecting wintering and breeding grounds in every part of the continent, from Alaska and Greenland through to Mexico and the Caribbean.
Over 75 per cent of Canadian wild bird species spend at least half of the year outside of Canada; representatives of all of these species are in all the flyways. Because the greatest number and variety of viruses have been seen in waterfowl and shorebirds and their large population, these birds have been the focus of live bird surveillance; most of the live birds sampled have been ducks.
On average, 16 per cent of live birds and one per cent of dead birds have so far tested positive for the low pathogenic North American viruses during the survey period. So far in 2015, 1134 live birds have been tested across Canada, with 93 positive for AI and three for H7 viruses that are not HPAI. In Ontario alone, 624 live birds have yielded 86 positives with no H5 or H7 so far. Also in 2015, 1576 dead birds have been tested across Canada, with 16 positive, four H5 and one H7 (not HPAI); in Ontario alone 266 have been tested with two positive and no H5 or H7. The updated results are available on the CWHC website at http://www.cwhc-rcsf.ca/data_products_aiv.php
But Parmley says that the surveillance effort has varied over the past ten years for several reasons. Survey objectives have changed and available resources have changed; sample sizes are low compared to real populations, and samples are taken haphazardly across the country, often piggybacking on bird banding procedures that may not necessarily be anywhere near poultry farms. We also need to be careful when extrapolating past results over a wide geographic region to the viruses of today.
Moving forward there are still many questions. Will virus based warnings even work? Can wild birds be sentinels? Ultimately we’re trying to develop an early warning system to predict risk and see how the virus is evolving, said Parmley, something she called “incredibly hard to do.” To better protect poultry farms, Parmley says this effort will take more resources – people, time and money.
When is the best time of year to test? How early do we disseminate findings to react in a timely manner? Does wild bird monitoring detect the risk sooner than monitoring the poultry population itself? Can we verify the signals and the risk associated with those signals to avoid an unnecessary response? Is there adequate infrastructure and political will to design and implement a sustainable system?
While wild birds are acknowledged as a reservoir for the AI virus, the relationship between hosts and virus remains diverse and complex. We need to further consider the epidemiological, climatological and agricultural differences across such a vast area, from the Arctic to the Caribbean, as well as at the interface between wild and farmed birds. So far we suspect that the virus can move through migratory birds, but it can also move through trade in poultry and poultry products as well as other human activities.
Nationally, for 2015/16, the goal of testing 1500 dead wild birds has already been exceeded. In Ontario the plan is to test 1500 live wild birds. One live trap site has been set within the control zone of the central Ontario AI outbreak in the spring of 2015.
Despite the challenges, so far Parmley reports a greatly improved understanding of the ecology and epidemiology of AI. We now have a better understanding of the role of waterfowl as a source and vector, the activity of the virus itself within the host, and a better grasp of how the virus is shed.
Beyond 2015, Parmley suggests a thorough process review to identify gaps, identify locations and populations that may be more vulnerable to infection, to help target both resources and surveillance. A national strategy would clarify roles, responsibilities and performance expectations.
“The virus keeps changing and so we need to keep learning,” said Parmley. The question that remains from the 2014/15 outbreaks in North America is how the virus got into poultry? “We can’t look at wild birds and domestic poultry separately – it is the points and places where these populations intersect where we need to focus our attention if we hope to prevent and prepare for the next outbreak.”
Study using genetic lines of Virginia Tech chickens reveals evolution happens faster than previously thought
November 4, 2015 - A critical component of an experiment that proved evolution happens 15 times faster than was previously believed relied upon genetic lines of chickens from Virginia Tech.
The discovery utilized the DNA of lines of White Plymouth Rock chickens that have been developed for more than 50 years.
The research was published recently in Biology Letters, a journal of Royal Society Publishing. The discovery involved researchers from several universities, including the University of York, Oxford University, the University of Sydney, Uppsala University, the Swedish University of Agricultural Sciences, and Virginia Tech.
“This experiment and many others involving everything from animal appetites to genetics could never have been done without the pedigree lines here at Virginia Tech,” said Siegel, distinguished professor emeritus of animal and poultry sciences in the College of Agriculture and Life Sciences. “This experiment was also an excellent example of international collaboration between six countries that was necessary for the success of the study.”
Siegel, along with Ben Dorshorst and Christa Honaker, also in the Virginia Tech Department of Animal and Poultry SciencesDepartment of Animal and Poultry Sciences, were co-authors on the paper.
The pedigree lines of White Plymouth Rock chickens were developed by Siegel, who began breeding them in 1957. From the common founder population, he produced two distinct lines of chickens selected for high- and low-body weight. Today, the high-weight line dwarfs its low-growth counterpart by an average of 12 times more by the time they reach the eight-week selection age.
In the latest experiment, researchers analyzed blood samples of chickens of the same generation using the most distantly related maternal lines to reconstruct how the mitochondrial DNA passed from mothers to daughters.
Mitochondria are specialized structures in the cells of animals, plants, and fungi that generate energy, synthesize proteins, and package proteins for transport to different parts of the cell and beyond.
Previously, estimates put the rate of change in a mitochondrial genome about 2 percent per million years,” Greger Larson, professor of archaeology at Oxford University, said in a news release. “At this pace we should not have been able to spot a single mutation in just 50 years, but in fact we spotted two.”
The sampling scheme yielded 385 mitochondrial transmissions that were analyzed for linkages within the mitochondrial DNA.
The rate of evolution was calculated by analyzing the number of observed mutations in the approximately 16,000 samples of mitochondrial DNA in the genome over 47 generations.
The scientists then reconstructed the maternal pedigree based on the mitogenome sequences.
“Our observations reveal that evolution is always moving quickly, but we tend not to see it because we typically measure it over longer time periods,” Larson said in the news release. “Our study shows that evolution can move much faster in the short term than we had believed from fossil-based estimates.”
The experiment also determined that mitochondria are not solely passed down from maternal lines. Strictly maternal inheritance has long been thought of as the characteristic of mitochondrial genomes.
“The thing everyone knew about mitochondria is that it is almost exclusively passed down the maternal line, but we identified chicks who inherited their mitochondria from their father,” said Michelle Alexander, lead author. This finding supports the theory that “paternal leakage” is not such a rare phenomenon.
This is not the first time the scientific community has benefited from the research done on Virginia Tech’s high- and low-body weight chicken lines.
A 2010 article in the scientific journal "Nature" highlighted a breakthrough in genetic studies of animal domestication, thanks in part to these two lines.
In 2010, the American Poultry Historical Society inducted Siegel into the American Poultry Association Hall of Fame, the industry’s top honor. In 2011, he was given an honorary doctorate from the Swedish University of Agricultural Sciences.
November 2, 2015 - The Department of Animal Biosciences is pleased to announce Elijah Kiarie has been appointed as the McIntosh Family Professor in Poultry Nutrition. Kiarie will join the department as an assistant professor effective January 1, 2016.
“We are very happy to welcome Dr. Kiarie into this important role for the department and the poultry industry,” shares Jim Squires, chair of the Department of Animal Biosciences. “He has experience in both academia and industry, which will be vital in supporting his success.”
“His superior understanding of industry needs and priorities showcase he is a great match for the demands of the new position,” Squires adds. “He will be working collaboratively to develop a world-class program that address the research opportunities presented in poultry nutrition.”
Kiarie will focus on the digestion of feed and absorption of nutrients, which will help improve efficiency. For example, feed still represents the main cost of production in the Ontario poultry industry. Global changes affecting corn, soybean and other ingredients have increased feed prices, a trend expected to continue.
Kiarie attained his Ph.D. at the University of Manitoba, where he was also most recently an adjunct professor. He has been a research scientist at DuPont Industrial Biosciences since 2011. Both his master’s and undergraduate degrees are from the University of Nairobi.
A donation from James and Brenda McIntosh, owners of McIntosh Poultry Farms Ltd. in Seaforth, Ont., established this new professorship position.
I was attracted to a review article on this topic in the September 2015 issue of the World’s Poultry Science Journal (Harlander-Matauschek et al, vol.71, pp 461-472). It is the outcome of an International Keel Bone Workshop held in Switzerland in 2014. For local interest, I also reviewed the paper of Petrik et al in Poultry Science, vol.94, pp579-585.
Unusually for a review paper, this one is primarily targeted at what is not known, and mainly consists of 9 recommendations for further study.
Most scientists in the field, and also experienced managers of layers, intuitively know that the keels of laying hens are susceptible to damage during the laying cycle. This was first brought to light several years ago when scientists in England examined carcases of spent hens following slaughter, and found a high incidence of keel damage and breakage. The degree to which this causes pain or distress during the life of the birds is not known.
In live birds, damage to the keel can only be determined by palpation, and there is no recognized standard method, or protocol for evaluating or reporting the results. There is also the distinction between actual fracture of the keel, and various levels of distortion or deformity. Fractures usually result in a callus around the fracture site that can be detected on handling the bird. So the first recommendation in the review paper is to develop a uniform method of evaluating keel bone damage so that future results will be comparable. Petrik et al studied only keel fractures.
The second recommendation was to investigate the kind of event or bird activity that results in keel damage. In non-cage systems, collisions with other birds and with furniture and equipment are thought to be some of the factors. However, even in conventional cages, keel damage occurs, but the reasons are not known.
Another unknown is whether initial deviation or distortion of the keel, from whatever cause, may result in keel fracture.
Do birds reared in different environments have different potential for keel bone damage in adult life? This is yet another unanswered question. Growing birds in an environment where wing flapping is encouraged is thought to improve locomotor skills and thus may avoid some of the (also largely unknown) challenges that result in keel damage.
In non-cage laying systems, individual birds as well as groups may display escape reactions to events that result in panic or fright. This can result in keel bone damage. These events may result from management activities and are thus susceptible to variation and potential improvement, but they must first be identified and studied.
As with any, even imprecisely measured, characteristic, there is always the question of a genetic influence. Interestingly, these 21st century scientists managed to find a study reported in 1955 showing that the tendency to develop keel deformity could be altered by genetic selection. Whether the methods used in this selection experiment would be relevant to contemporary keel damage observations would need to be confirmed.
If genetics is involved, can nutrition also play a part in affecting keel bone damage? The answer to this question is, of course, related to how nutrition influences bone development and maintenance. And this in turn may be related to the interactions involved in egg shell deposition and bone integrity. The likelihood of direct involvement of calcium balance as it affects shell deposition and keel bone integrity is probably low. This is because the calcium flow from bones to the egg shell gland is from the long bones and not the keel.
There are large differences in keel fracture incidence between housing systems and even within similar systems. Perches, although considered desirable from a welfare standpoint, seem to result in elevated keel damage and fracture. But different materials used for perches result in widely variable keel damage. Round metal perches seem to be inferior to other designs. Petrik et al’s work in Ontario compared keel fractures in conventional cages with single tiered floor housing and found almost double the incidence in the floor systems.
The final recommendation from the Harlander-Matauschek paper in to investigate and quantify keel bone damage and production losses. A new report (as yet unpublished) shows that birds with keel fractures laid eggs with reduced shell breaking strength. This would represent a serious challenge if confirmed. The fact that most of the keel fractures appear to occur during the period of peak egg production would suggest that the nutrient status of the affected birds is inadequate to support both maximum egg production and bone maintenance. The inadequacy must be minimal though, since many flocks continue to lay at or near peak level for many months and if keel damage is compromising productivity, its effect must be very small.
In reading this research, one can sense the authors’ frustration at the lack of clear information. Obviously, much more research is needed before industry would be able to take firm action to deal with this problem.
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