Jul. 9, 2012 - Hyperimmune egg yolk antibodies can be used to help control intestinal diseases in poultry, according to U.S. Department of Agriculture (USDA) scientists.
The antibiotic-free technology involves extracting antibodies from egg yolks from pathogen-free hens or female chickens that have been hyperimmunized—injected with a vaccine that contains inactivated pathogenic organisms. Hyperimmunized birds have a greater-than-normal immunity and produce a large amount of antibodies.
Avian immunologist Hyun Lillehoj at the Agricultural Research Service (ARS) Animal Parasitic Diseases Laboratory in Beltsville, Md., partnered with ARS colleagues, university scientists and collaborators from the Mexican company IASA (Investigacíon Aplicada, S.A.) on the studies. ARS is USDA's chief intramural scientific research agency, and this research supports the USDA priority of promoting international food security.
The group demonstrated the effectiveness of inducing passive immunity in young birds, which have no immune protection right after hatching, against coccidiosis, a devastating poultry disease.
Birds affected by coccidiosis are unable to absorb feed or gain weight. The disease costs the poultry industry more than $600 million in the United States and about $3 billion worldwide each year.
Treatments used to reduce the spread of disease include good management practices and live vaccinations. However, antibiotic-free alternatives are important to help fight drug-resistant strains and for organic poultry farmers, according to Lillehoj.
In the study, one-day-old chickens were given feed mixed with spray-dried egg yolk powder prepared from hens hyperimmunized with multiple species of the parasite Eimeria, which causes coccidiosis. The chickens were then exposed to live coccidia parasites. Chickens that had received the hyperimmune egg yolk antibodies gained more weight and shed significantly fewer Eimeria in their feces. The treated birds also had less gut lesions than chickens that did not receive the treatment.
A commercial product that helps control coccidiosis has been developed by a private company based on results of this research. In the future, similar methods may be used to help prevent other harmful poultry diseases.
Read more about this research in the July 2012 issue of Agricultural Research magazine.
Jul. 9, 2012 - In a joint study, researchers at the Johns Hopkins Center for a Livable Future (CLF) and Arizona State University found evidence suggesting that a class of antibiotics previously banned by the U.S. government for poultry production is still in use. Results of the study were published in Environmental Science & Technology.
The study, conducted by the CLF and Arizona State's Biodesign Institute, looked for drugs and other residues in feather meal, a common additive to chicken, swine, cattle and fish feed. The most important drugs found in the study were fluoroquinolones—broad spectrum antibiotics used to treat serious bacterial infections in people, particularly those infections that have become resistant to older antibiotic classes. The banned drugs were found in 8 of 12 samples of feather meal in a multi-state study. The findings were a surprise to scientists because fluoroquinolone use in U.S. poultry production was banned by the U.S. Food and Drug Administration in 2005.
This is the first time investigators have examined feather meal, a byproduct of poultry production made from poultry feathers, to determine what drugs poultry may have received prior to their slaughter and sale.
The annual per capita human consumption of poultry products is approximately 100 pounds, greater than that of any other animal- or vegetable-derived protein source in the U.S. To satisfy this demand, each year, the U.S. poultry industry raises nearly 9 billion broiler chickens and 247 million turkeys, according to the U.S. Department of Agriculture. A large percentage of the fresh weight of these animals is inedible—an estimated 33 percent for chickens, for example—and is recycled for other uses, including feather meal.
The rendering industry, which converts animal byproducts into a wide range of materials, processes poultry feathers into feather meal, which is often added as a supplement to poultry, pig, ruminant, and fish feeds or sold as an "organic" fertilizer. In a companion study, researchers found inorganic arsenic in feather meal used in retail fertilizers.
"The discovery of certain antibiotics in feather meal strongly suggests the continued use of these drugs, despite the ban put in place in 2005 by the FDA," said David Love, PhD, CLF Project Director and lead author of the report. "The public health community has long been frustrated with the unwillingness of FDA to effectively address what antibiotics are fed to food animals."
A primary reason for the 2005 FDA ban on the use of fluoroquinolones in poultry production was an alarming increase in the rate of the fluoroquinolone resistance among Campylobacter bacteria. "In recent years, we've seen the rate of fluoroquinolone resistance slow, but not drop," noted study co-author Keeve Nachman, PhD, Farming for the Future Program Director at CLF. "With such a ban, you would expect a decline in resistance to these drugs. The continued use of fluoroquinolones and unintended antibiotic contamination of poultry feed may help explain why high rates of fluoroquinolone-resistant Campylobacter continue to be found on commercial poultry meat products over half a decade after the ban."
In the U.S., antibiotics are introduced into the feed and water of industrially raised poultry, primarily to make them grow faster, rather than to treat disease. An estimated 13.2 million kilograms of antibiotics were sold in 2009 to the U.S. poultry and livestock industries, which represented nearly 80 percent of all antibiotic sales for use in humans and animals in the U.S. that year.
In conducting the study, researchers analyzed commercially available feather meal samples, acquired from six U.S. states and China, for a suite of 59 pharmaceuticals and personal care products. All 12 samples tested had between 2 and 10 antibiotic residues. In addition to antimicrobials, 7 other personal care products, including the pain reliever acetaminophen (the active ingredient in Tylenol), the antihistamine diphenhydramine (the active ingredient in Benadryl) and the antidepressant fluoxetine (the active ingredient in Prozac), were detected.
Researchers also found caffeine in 10 of 12 feather meal samples. "This study reveals yet another pathway of unwanted human exposure to a surprisingly broad spectrum of prescription and over-the-counter drugs," noted study co-author Rolf Halden, PhD, PE, Co-Director of the Center for Health Information & Research, and Associate Director of the Swette Center for Environmental Biotechnology at Arizona State University.
When researchers exposed several strains of E. coli bacteria to the concentrations of antibiotics found in the feather meal samples, they also discovered the drug residues could select for resistant bacteria. "A high enough concentration was found in one of the samples to select for bacteria that are resistant to drugs important to treat infections in humans," noted Nachman.
"We strongly believe that the FDA should monitor what drugs are going into animal feed," urged Nachman. "Based on what we've learned, I'm concerned that the new FDA guidance documents, which call for voluntary action from industry, will be ineffectual. By looking into feather meal, and uncovering a drug banned nearly 6 years ago, we have very little confidence that the food animal production industry can be left to regulate itself."
June 29, 2012 - U.S. Department of Agriculture (USDA) scientists have developed a new method to create antimicrobials that kill disease-causing pathogens. These antimicrobials can be used as an alternative to antibiotics.
Growing concerns about antibiotic resistance to certain strains of bacteria and increasing restrictions on the use of antibiotics in animals has accelerated the need to find alternatives. Scientists with the Agricultural Research Service (ARS), the chief intramural scientific agency of USDA, are working to provide new strategies for enhancing production and improving overall animal health. This research supports the USDA priority of promoting international food security.
The patented technology for designing pathogen-targeted antimicrobials is the work of molecular biologist David Donovanat the ARS Henry A. Wallace Beltsville Agricultural Research Center (BARC) in Beltsville, Md. Donovan works in the center's Animal Biosciences and Biotechnology Laboratory.
Viruses that infect bacteria, called bacteriophages (phages), produce enzymes that can be used to kill pathogens. These novel enzymes have been shown to be effective in killing pathogens like streptococci and methicillin-resistant Staphylococcus aureus, also known as MRSA.
Collaborating with industry, university and federal scientists, Donovan demonstrated that these particular enzymes have molecular domains that can be isolated and will act independently of their protein surroundings. They kill bacteria by eating or chewing up the walls of cells.
The enzymes can be manipulated to create an antimicrobial that targets and kills only specific pathogens. This greatly reduces the probability that non-targeted bacteria will develop resistance.
Read more about this research in the May/June 2012 issue of Agricultural Research magazine.
June 29, 2012 - Natural compounds may offer an alternative to certain antibiotics in the future for treating young animals that are susceptible to bacterial infections, thanks to work by U.S. Department of Agriculture (USDA) scientists.
Researchers at the Agricultural Research Service (ARS) Food and Feed Safety Research Unit in College Station, Texas, have invented a new method that involves using chlorate (sodium or salt) and nitro compounds to significantly reduce or eliminate intestinal bacterial pathogens in animals such as piglets and calves. Nitro compounds are organic substances that contain one or more nitro groups, which consist of three atoms—one of nitrogen and two of oxygen—that act as one.
ARS is USDA's chief intramural scientific research agency.
Chlorate and nitro compounds have proven to be effective against the foodborne pathogens Salmonella and Escherichia coli O157:H7. Salmonella alone causes more than 1.3 million cases of human foodborne disease each year, at a cost of $2.4 billion. Salmonella and certain E. coli strains also cause considerable losses to the swine and cattle industries due to enteric or intestinal diseases of newborns.
Microbiologist Robin Anderson and his colleagues at the College Station unit demonstrated the effectiveness of a chlorate-based compound in earlier research by mixing it into water or feed and giving it to cattle. The compound, which was highly effective in reducing E. coli., has been licensed by a private company. Chlorate also reduced Salmonella in turkeys and broiler chickens.
In addition, scientists looked at using certain nitro compounds as a method to control foodborne bacteria. Salmonella or E. coli bacteria were treated with or without chlorate and with or without nitro compounds. Chlorate was found to have significant bacteria-killing activity against E. coli and Salmonella. However, chlorate has not been approved for commercial use in food animals by the U.S. Food and Drug Administration. When the nitro compound was added, the activity was enhanced 10- to 100-fold. Nitro compounds alone had significant bacteria-killing activity, which was more persistent than that of chlorate.
Anderson and his team concluded that nitro and chlorate compounds together were the best treatment—a combination that could offer an alternative to certain antibiotics that are commonly used to treat diarrheal infections in young animals.
Read more about this research in the May/June 2012 issue of Agricultural Research magazine.
The federal government has provided the Atlantic Poultry Research Institute (APRI) at the Nova Scotia Agricultural College with $600,000 to assist its feed and health research.
In announcing the grant on behalf of federal Agriculture Minister Gerry Ritz, Scott Armstrong, the Cumberland-Colchester-Musquodoboit Valley MP, said the research investment will help Atlantic Canadian poultry producers remain competitive, “by ensuring they continue to improve upon their quality products in order to meet the demands of today’s health-conscious consumer.”
Six projects will receive funds for research into better nutrients and improved disease resistance for the regional poultry industry. This funding will benefit consumers, as it will support research into ways to increase omega-3 fatty acids and antioxidants in eggs and chickens, plus ways to improve flock health and reduce disease.
The research projects also include the identification of healthy, cost-effective alternatives to traditional feed, such as omega-rich crab meal, canola seeds and cold-pressed canola oil, development of a new approach to vaccination, as well as finding an alternative to antibiotics to ensure poultry health while assuring the concerns of safety-conscious consumers.
According to APRI’s CEO, Dr. Derek Anderson, all programs will be completed by Dec. 31, 2013, and the research aims to “find some answers for the poultry industry with respect to alternatives to antibiotics and the efficacy of feeding low protein diets formulated to meet amino acid requirements of laying hens by using synthetic amino acids.”
Dr. Anderson also hopes to reduce the cost of poultry diets without having detrimental effects on production performance. Methods include the use of opportunity feed ingredients and the development of omega-3 fatty acid enriched eggs by feeding crab meal.
The Canadian Agricultural Adaptation Program’s four councils in the Atlantic region, led by Agri-Futures Nova Scotia, will deliver the investment in the research projects.
Nova Scotia will also contribute $220,000 to the projects from its Technology Development Program. Nova Scotia Minister of Agriculture John MacDonell observed: “The Government of Nova Scotia is investing in these projects to support scientific research that will improve the poultry sector’s adaptability, competitiveness and innovation.”
As of 2010, Atlantic Canada’s 235 chicken, turkey and egg farmers generated $259 million in revenue at the farm gate.
The research is also heavily producer-driven, said Dr. Anderson.
He noted: “APRI is an Atlantic-wide institute that has successfully leveraged funds from the industry and from government to further its applied research needs, which in turn are identified with input from each of the Atlantic provinces’ poultry marketing boards.”
Anderson added that, for the APRI, the new research grant means active research on broiler chickens and laying hens will provide training related to poultry for graduate students and research personnel.
For the producers, he continued, it could mean lower cost diets, alternative feed ingredients, as well as alternatives to antibiotics for broilers and increased broiler weight gains.
He also emphasized APRI works from producer-generated priority lists and the organization supplied the foundation dollars to start the funding process.
Dr. Ian Duncan, Dr. Steve Leeson and the late Dr. Bruce Hunter were each recipients of a 2012 Poultry Worker of the Year Award in Guelph, Ont., on May 8 during a ceremony at the Poultry Industry Council’s Spring Symposium. The annual award recognizes individuals who have made a significant contribution to the poultry industry.
Duncan, who earned his PhD in Scotland, began his career with groundbreaking research on frustration and conflict behaviour of domestic fowl. His first published work on animal welfare in 1975 is now regarded as the pioneering foundation of the animal welfare work being done today.
During his tribute, friends described Duncan as a world-renowned researcher and tireless mentor for students. He has published more than 150 papers on animal welfare and has left a legacy in teaching, challenging and inspiring thousands of people, colleagues and students.
How important is a nest to a hen? Duncan has spent his career trying to find the answers to such questions, investigating beyond simple biological functions to question what’s going on in their heads. Duncan had a way of making chicken research fun, all the while making people think about the importance of how animals feel and finding ways to measure those feelings.
In his acceptance speech, the now professor emeritus and chair in animal welfare at the University of Guelph acknowledged that some of his work has “caused some pain” in the industry, but he hopes that people can look back in 10 years and say, “That sod was right!”
Regarded as the “god of poultry nutrition,” Steve Leeson has made a high-impact contribution to the poultry industry through the volume and quality of his work. He has authored or co-authored 18 books, 351 articles in refereed journals and 82 articles in trade journals, averaging out to one publication per month over the course of his career. He has also advised or co-advised more than 40 graduate students from around the world.
Leeson’s focus has been on nutrition, not only for birds but for people as well. Craig Hunter of Burnbrae Farms said that Leeson had a real sense of research priorities that were relevant to the industry, and he credited Leeson with opening up a new era of production and marketing opportunities with such designer egg products as omega-3 eggs.
“I’ve gotten a few awards over the years but none means more than this because this is from you,” said Leeson to his peers in his acceptance speech.
During a very emotional presentation, Daina Hunter accepted the award on behalf of her late husband, Dr. Bruce Hunter, who passed away suddenly in October 2011 at the age of 61. The award acknowledged Hunter’s 33 years of teaching and research that encompassed poultry and fur farming, as well as environmental conservation.
Hunter started his career with exotic birds and reptiles, running the Ontario Veterinary College wild bird clinic for more than 15 years. He wrote what is known as “Bruce’s Black Book on Mink Farming” – the recognized “go-to” handbook for that industry. He retired from the OVC department of pathobiology in 2010 as a full professor.
Hunter was instrumental in setting up a Canadian Community of Practice in EcoHealth (CoPEH) and a graduate-level course in ecosystem approaches to health involving University of Guelph, the University of British Columbia and Université du Québec à Montréal. He was also co-leader of a poultry project in Ghana for Veterinarians Without Borders.
Strong, Silent type
Robert Jacobs, chair of pathobiology at OVC, described Hunter as the “strong, silent type with a spontaneous smile” who was humble to the point of being apologetic. “He left a legacy of unselfishness and a love of people,” said veterinarian Mike Joyce. Al Dam, OMAFRA poultry specialist, said that Hunter always had time for everyone and made you feel like you already had the answer to your own questions, “he just teased it out of you.”
During his tribute, friends described Hunter as “Grizzly Adams” in appearance, a man well respected as a teacher, mentor and collaborator who had a natural gift for communication and the ability to bring people together.
On May 8, 2012, the Poultry Industry Council (PIC) held its Spring Symposium (formerly known as Research Day), celebrating the careers of three distinguished poultry researchers, as well as highlighting research regarding poultry health and disease that it helps fund.
The day began with the presentation of the Poultry Worker of the Year Award to Ian Duncan, who did groundbreaking work on laying hen welfare, and poultry nutrition researcher Steve Leeson. Also honoured was the late Bruce Hunter, a much beloved teacher and researcher from the Ontario Veterinary College. Each award was preceded by a short video featuring colleagues and peers discussing the recipients’ accomplishments and significance to the field. All of the honorees were emotional and extremely thankful, none more so than Bruce Hunter’s widow, who was noticeably touched by the kind words said.
The rest of the day was devoted to researchers discussing various aspects of poultry health and disease, beginning with Jean-Pierre Vaillancourt from the University of Montreal, who discussed putting disease into perspective.
Vaillancourt stated that animal loss due to disease is a continuous and significant problem that claims a large number of animals each and every year. Inside the poultry system, he said, diseases constantly change and adapt, and therefore it is a constant battle between management and prevention.
He also said that as density continues to increase, productivity will continue to decrease because production diseases and infection pressure will rise. “The potential costs are huge if we are unprepared,” he said, “and can have major effects on human health as well.”
The second speaker at the symposium was Cindy-Love Tremblay, a PhD student at the University of Montreal studying antimicrobial resistance in birds and how normal gut flora could acquire resistance. Her results have shown that healthy poultry could be a reservoir for resistance genes, which could quickly spread throughout a population of bacteria.
Although the research is only in its early stages, Tremblay said that future work could be used to help reduce resistance by decreasing the ability of the bacteria to exchange genes.
Shayan Sharif from the Ontario Veterinary College at the University of Guelph followed with an explanation on the potential uses of probiotics in humans, as well as poultry. According to him, the use of a combination of probiotics in chickens can help modulate the immune response, increase weight gain, improve feed conversion and decrease both mortality and overall parasite/bacteria load.
This was demonstrated in tests using a cocktail of three different probiotic bacteria; the researchers found that the cocktail can help enhance the chickens’ immune response. Research is also being done on the potential antibacterial properties of probiotics using a new cocktail of five different probiotics targeted against a specific strain of Salmonella.
Ben Wood, a geneticist from Hendrix Genetics, then took to the podium to discuss the challenges associated with selecting for specific traits in turkeys. He said that screening for metabolic disorders with a genetic basis are quite effective, but artificially selecting against behaviour and pathogen resistance is more difficult.
The reason for this, Wood said, is that, by selecting for improved resistance, the results visibly decrease the presentation of commercially viable traits, such as growth rate and feed conversion. “And until breeders get the word that consumers are willing to pay for less product,” he added, “things aren’t going to change.”
The final scientific presentation was by Michele Guerin from the University of Guelph on the prevalence of Salmonella serovars in breeder flocks in Ontario. The results showed that there was a seasonal difference between Salmonella’s presence in breeders (more pronounced in the fall) and hatcheries (summer), and that the best way to eliminate an outbreak is constant monitoring at the breeder flock and hatcheries across all poultry types. She noted that if she and her research team could gain a better understanding of why these seasonal patterns occur, they could design studies to show how these infections could be prevented.
Len Jewitt, owner of BLT Farms Inc., a turkey, egg and broiler operation north of Guelph, ended the day with an emotional presentation on the impact of disease at the farm level. Jewitt, who several years ago had one of his layer barns test positive for Salmonella enteritidis (SE), he explained that there are many costs to the producer when disease strikes, and these go beyond dollars and cents.
The biggest challenge was the mental cost. “This is something that as an industry, we don’t want to talk about,” he said.
He said the positive result made him feel “like a loser,” and he asked himself what had gone wrong, as he and his employees had been so clean and had followed all necessary protocols.
He finished his talk with a piece of advice for those who are responsible for going on the farm and beginning the depopulation and disinfection process – to use a gentle hand. “Remember you are walking into someone’s dreams,” he said.
Concern for the welfare of laying hens housed in conventional battery cages, a behaviourally restrictive housing environment, is growing, and an increasing number of producers are preparing to transition to alternative housing systems such as furnished cages. However, converting to new housing systems is not as simple as placing hens into them and being rewarded with good welfare and high production. Although furnished housing provides more behavioural freedom, it presents other challenges.
To address the challenges of intensive and competitive production in these alternative cage environments, Dr. Michelle Jendral and her research team at the Nova Scotia Agricultural College have been evaluating laying hen production in furnished cage systems. Their overall goal has been to compare production, physiological, behavioural and condition parameters of three laying hen strains: Lohmann Brown (LB), LL (LL) and Shaver White. The hens were housed in conventional battery and furnished large group cages over two production cycles, to assess hen health, welfare and productivity in, and strain suitability to, the different housing environments.
Included in this large, multidisciplinary study was an assessment of the prevalence and severity of osteoporosis and bone fractures, as determined from the incidence of breaks during the production cycle and after processing, as well as the bone breaking strength at end of cycle, feed consumption, egg production and quality, and calcium metabolism efficiency during the production period. Behaviour was monitored through live observation and digitally recorded footage to quantify hen prelay and nesting behaviour, dustbathing and amenity use, aggression, stereotypies, comfort and locomotory activity. Condition of the integument was monitored to further assess hen health, and blood white cell counts and tonic immobility were conducted to assess hen stress and fear.
Their findings? In contrast to previous findings in Dr. Jendral’s laboratory, when hens were housed at 450 cm2 in furnished and conventional cages, the current study housed birds at 660 cm2, and no treatment differences in femoral or tibial bone breaking strength were found. The increased floor space allowance in the current trials may have encouraged sufficient static walking activity in conventional cages to contribute to structural bone preservation. Notably, treatment differences in furcula, keel, pubis, wing and leg bone fractures were largely absent throughout the production periods, possibly reflecting the positive impact of increased floor space provision on structural bone preservation. However, humeral breaking strength values were lower in conventional than in furnished cages, suggesting that providing increased cage height and raised amenities such as perches and a dustbath, which increase hen opportunity for wing movement, is necessary to maintain humeral architecture in caged hens. Furthermore, a high incidence of processing-related fracture was seen in both housing treatments, suggesting that cumulative structural bone loss remains a concern in commercial strains, and that genetic selection for birds that are better able to preserve structural bone should remain a priority. In the more prohibitive conventional cage environment, lighter hybrid strains were also more susceptible to osteoporosis. Importantly, both humeral and femural bone data from this study support the provision of increased floor space and cage height above current national standards.
Despite findings that hens housed in furnished cages at 450cm2 consume more feed than hens housed in conventional cages at the same density, housing treatment differences in feed consumption were not observed in the current flocks.
This suggests that at a greater floor space provision, freedom of movement is increased in both systems, and movement is sustained through similar energy intake. Notably, in both housing systems, and at all ages, LB hens consumed the most feed, followed by LL and then Shaver White hens.
Strain differences in body weight were apparent in both conventional and furnished cages at both peak and late production, with LB hens weighing the most on average, followed by LL and Shaver White. Significant changes in body weight, primarily observed for LB hens, emphasize the importance of group size, management and housing interaction on bird health.
Treatment differences in egg production and quality were largely absent. In both systems, LB hens produced heavier eggs than Lohmann White and Shaver White hens and had stronger shells, and LB and Shaver White hens appeared to better maintain shell thickness with age than LL. Overall, eggs from LB and Lohmann White hens were found to be stronger than those from Shaver White. Since Jendral et al. (2008) previously observed treatment differences in egg quality when hens were housed in furnished cages and conventional cages at 450 cm2 usable floor space, but did not in this study, in which hens were housed at 660 cm2, bone and egg findings from the current research suggest that increasing floor space allocation for caged hens contributes to both bone and egg quality.
Prelay behavioural findings indicate that provision of a nest box in furnished cages permitted expression of normal nesting activity, resulting in an overall decrease in hen frustration. As a result, hens showed increased expression of comfort behaviour, which was likely facilitated by the higher cage height in furnished cages and the additional floor space created in the cage area when the nest box was in use. Reduced aggressive pecking in general, and reduced feather pecking for LL hens, was also observed in furnished cages. High levels of and variation in displacement activity in both systems suggest that nesting was frustrated in conventional cages, and that competition for the nest space did occur in the large group furnished cages, as also evidenced from some nesting in the cage area in furnished cages.
Despite the competition for the dustbathing space in large group furnished cages, as evidenced by aggressive pecking in all strains and reduced bathing activity by larger LB birds, hens in these cages used the facility to express dustbathing and foraging behaviours. The provision of a dustbath in which the smaller LL and Shaver White hybrids could dustbathe, and the larger LB hybrids could predominantly forage, likely minimized the expression of feather pecking behaviour. Dr. Jendral believes these findings provide evidence that foraging and dustbathing are highly motivated behaviours, and permitting hens to express these activities mitigates the performance of redirected damaging behaviours. Amenity space provision, design and timing of substrate delivery must be further examined to reduce competition for bathing and foraging facilities in cage environments.
Total feather condition did not differ between treatments early in the production cycles; however, treatment and strain differences were apparent with age. Also, considerable variation in individual hen feather cover existed within the cages. In furnished cages, this was likely reflective of the large and potentially unstable group size, which from the behavioural data, appears to have led to competition for amenities, and feather pecking of subordinate birds.
In conventional cages, frustrated nesting activity, as evidenced from the prelay behavioural data and redirected foraging and bathing activity, likely contributed to feather pecking. In general, hens in furnished cages had improved back, breast and wing condition over conventionally caged hens, which provides evidence that despite the large and likely unstable group size, provision of amenities in furnished cages permitted behavioural expression that reduced frustration and redirected feather pecking activity. High variability in hen condition in furnished cages combined with the absence of treatment differences in hen stress and fear response provide additional evidence that, despite increased freedom of behavioural expression in furnished cages, the large group size in furnished cages is nonetheless contributing to hen stress.
The findings from this research provide compelling evidence for the production and welfare benefits conferred by providing caged hens with adequate space and amenities to express natural and load-bearing activities. Variation in individual hen and overall strain response to large group housing suggests that further studies examining group size, in combination with stocking density, strain analyses and amenity design must be conducted. Layer breeding programs must also continue to be adapted to select against metabolically and environmentally induced disorders. To read more, please visit www.poultryindustrycouncil.ca.
Michelle J. Jendral completed her PhD in Animal Science in August 2008, at the University of Alberta. The focus of her doctoral research concerned the development of sustainable cage and non-cage housing systems for laying hens that balance hen productivity, health and well-being. Currently, Michelle is an assistant professor, Poultry Behaviour and Welfare, at the Nova Scotia Agricultural College in Truro, N.S., where she is continuing her research in laying hen housing systems. Additional research interests include production and welfare issues facing the poultry industry, poultry behaviour, neuroethology and cognitive processes, and the importance of the human-animal interaction in animal production. Michelle teaches courses in domestic animal behaviour, avian biology, avian production systems, applied ethology and animal welfare.
Concerns over the presence of mycotoxins, the secondary toxic metabolites produced by various moulds in poultry feed, are nothing new. Major effects on birds include poor weight gain/egg production, reproduction and immunity.
Historically, mycotoxin research focused on the effects of a single mycotoxin, but in the last decade or so, research has turned towards uncovering the menacing world of toxic interactions that can occur when two or more different mycotoxins are present in feed. “These interactions can lead to toxicity at very low concentrations – concentrations at which no toxicity is expected when we look at each mycotoxin in isolation,” says Dr. Swamy Haladi, global technical manager, mycotoxin management team at Alltech Canada in Guelph, Ontario.
Haladi and his Alltech colleague Dr. Ted Sefton, along with University of Guelph scientists Dr. Herman Boermans and Dr. Niel Karrow, have been trying to understand these interactions based on the published research work. “Toxicity from interactions has already been assessed when two different mycotoxins are present in the same feed (see table), but the issue gets more complicated when three or more mycotoxins are present,” Haladi explains. “With some mycotoxins, their combined toxicity is simply their individual toxicity levels added together. However, with some, there is a synergistic interaction that makes the feed far more toxic than one would predict.”
Mycotoxins in feed
The most significant mycotoxins for the global poultry industry include aflatoxins, ochratoxins, T-2 toxin, deoxynivalenol (DON), fumonisins and zearalenone (ZEA). Fusarium mycotoxins such as DON and ZEA are the most common and widespread throughout Canada, while ergot toxins tend to be a bigger challenge in Western Canada. Haladi says other Fusarium mycotoxins such as 3-acetyl DON, and 15-acetyl DON are also frequently found in Canadian feedstuffs at low levels, but they are seldom tested for. “Although not common, T-2 toxin and its related compounds may also be present,” he notes.
Haladi also says that research from Dr. Trevor Smith’s lab at University of Guelph shows that turkeys are the most sensitive poultry species to Fusarium mycotoxins, and among chickens, laying hens have higher risk than broiler chickens due to their long-term exposure.
Since one mould can produce several mycotoxins, and several moulds can be present in one feedstuff, it is expected that there are likely more mycotoxins present in a given feed sample than are being tested for. “If a sample contains T-2 toxin, for example, chances are there are several others, likely HT-2 toxin and neosolaniol, present as well,” Haladi explains. “We know now that these toxins contribute to the toxicity of T-2 toxin, but because we neither test for their presence nor had a way of analyzing their interactions, we have a false sense of security about that sample of feed. This is why it’s so important to be able to test for and analyze as many toxins as possible in an affordable and timely manner.”
To be able to assess the toxicity of a feed containing multiple mycotoxins, Haladi and his colleagues propose a ‘Toxicity Index’ (TI) for each mycotoxin present in the feed based on published ‘LD50 values’ (these values are the concentration at which half the one-day-old chicks that ingest it, perish).
“The TIs are calculated using the ratio of LD50 value of the least toxic mycotoxin by the LD50 value for each of the other mycotoxins identified,” Haladi explains. “Each TI is then multiplied by the corresponding mycotoxin concentration in the feed. The products of such multiplication are then added to obtain a total mycotoxin concentration, which can then be used to predict the potential toxicity of the feed.”
Being able to calculate a TI value for every feed sample depends on two main factors – the first being to identify and quantify all mycotoxins in feed. Haladi says quick ELISA mycotoxin tests are important for use on grain at Canadian feed mills, but that test only screens for DON. “This is where Alltech’s 37+ Program will be able to help,” Haladi says. “It will be commercialized this year, and will allow 38 mycotoxins to be analyzed in a single run using sophisticated analytical equipments such as Ultra Pressure Liquid Chromatography with double mass spectrometry.” According to Haladi, this methodology is very accurate and sensitive. “Our recent analysis of 37+ Program has shown that more than 90 per cent of North American feed ingredients contained one or more mycotoxin,” says Haladi. “About 45 per cent of samples contained five or more mycotoxins.”
The other factor is that not all LD50 values have been determined. “More research to find LD50 values for the less-studied mycotoxins is needed,” Haladi notes.
“There is no single magic bullet for mycotoxin control,” he concludes. “Mycotoxins are formed in the field as well as in storage. Minimizing mycotoxin production is a matter of using various management programs on-farm and at feed mills.
However, knowing the toxicity that results from interactions between toxins is another tool to help the poultry industry reach better bird health and productivity.”
Some mycotoxin interactions in poultry
Dr. Swamy Haladi says that with some mycotoxins, their combined toxicity is simply their individual toxicity levels added together. However, with some, there is a synergistic interaction that makes the feed far more toxic than one would predict.
Mycotoxins – Type of interaction
Aflatoxin B1 X Ochratoxin A – Synergistic
Aflatoxin B1 X Diacetoxyscirpenol – Synergistic
Aflatoxin B1 X T-2 toxin – Synergistic
Aflatoxin B1 X Cyclopiazonic acid – Additive
Aflatoxin B1 X Deoxynivalenol – Additive
Ochratoxin A X T-2 toxin – Additive
Ochratoxin A X Cyclopiazonic acid – Additive
T-2 toxin X Deoxynivalenol – Synergistic
T-2 toxin X Fumonisin B1 – Additive
Fumonisin B1 X Moniliformin – Additive
Fumonisin B1 X Fusaric acid – Synergistic
(source: Devegowda and Krishnamurthy, 2005)
Dr. John Prescott and his team of researchers at the University of Guelph have taken significant steps towards a better understanding of necrotic enteritis and developing a vaccine that can protect broiler chickens from the disease.
Why an NE vaccine?
Necrotic enteritis (NE) is among the most common enteric (intestinal) diseases in poultry. It is caused by the bacterium Clostridium perfringens, which adheres and causes damage to gut tissues. Left unchecked, this damage can impair nutrient absorption and in some cases open the door to other gut infections such as coccidiosis. An NE-affected flock may suffer from increased mortality, but often “sub-clinical” cases don’t present any signs other than reduced flock performance. Without obvious signs, these cases can go unnoticed, and therefore untreated. Reduced performance, increased mortality and correlation with other diseases add up to significant losses for the industry, with some estimates as high as $2 billion a year globally. NE is currently controlled with antibiotics; however, increasing concern over antibiotic resistance are putting pressure on the industry to find alternative methods of disease control.
NE is more complex than we thought
Research from around the globe suggests that C. perfringens carries specific genes associated with its ability to cause disease. However despite extensive study, it is not entirely clear why some strains of the bacterium cause disease while others do not. Dr. Prescott’s group has confirmed that several of these so-called ’virulence’ genes can be found on small, portable strands of DNA known as plasmids that are readily passed from one bacterium to another. Genetic analysis reveals the plasmid DNA sequences are often re-arranged during transfer resulting in a variety among bacteria; some strains have the information that confers the ability to cause disease whereas others do not. Dr. Prescott has been able to identify genes common among virulent strains of C. perfringens and determine which are important for causing NE.
What is becoming clear from this and other research around the world is that it is likely the combined effects of several bacterial genes, each with different functions, that contribute to the development of NE. For example, one of the genes identified is responsible for production of a secreted protein that may be crucial to the bacterium’s ability to adhere to cells in the bird’s intestine. Another gene directs bacterial production of a toxin that contributes to the intestinal cell damage associated with NE. Continuing research into the complexities of this disease is revealing insights into potential strategies for its control.
A vaccine in THE making
Dr. Prescott’s approach to controlling NE is to identify the bacterial proteins that contribute to development of NE then immunize the bird against them – if the bird’s immune system can neutralize the effect of one or more of these proteins, NE is much less likely to develop. To be effective, this strategy would elicit an immune response in the intestine. The researchers started with a Salmonella vaccine that can do just that. Using modern molecular biology techniques, they modified the vaccine so it could confer resistance to Clostridia in addition to Salmonella. Early tests of this strategy show that immunized broiler chickens can be protected from NE, and further tests are underway to confirm these exciting results.
The researchers will further characterize the roles that selected virulence genes play in development of NE. Based on these results, additional vaccine vectors may be engineered that elicit immune responses to one or more gene products. Candidate vaccines will be tested for their ability to protect birds from C. perfringens challenge and vaccination protocols will be optimized.
Establishing an effective, stable vaccine platform with which to mitigate the effects of NE would be of great benefit to the poultry industry, especially in the face of increasing pressure to find alternative means to control this important disease.
The CPRC, Poultry Industry Council and the Ontario Ministry of Agriculture, Food and Rural Affairs provided funding for this work in partnership with Agriculture and Agri-Food Canada as part of Growing Forward, a federal-provincial-territorial initiative.
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.
June 22, 2012 - It might be possible for human-to-human airborne transmissible avian H5N1 influenza viruses to evolve in nature, new research has found. The findings, from research led by Professor Derek Smith and Dr Colin Russell at the University of Cambridge, were published today, 22 June in the journal Science.
Currently, avian H5N1 influenza, also known as bird flu, can be transmitted from birds to humans, but not (or only very rarely) from human to human. However, two recent papers by Herfst, Fouchier and colleagues in Science and Imai, Kawaoka and colleagues in Nature reveal that potentially with as few as five mutations (amino acid substitutions), or four mutations plus reassortment, avian H5N1 can become airborne transmissible between mammals, and thus potentially among humans. However, until now, it was not known whether these mutations might evolve in nature.
The Cambridge researchers first analysed all of the surveillance data available on avian H5N1 influenza viruses from the last 15 years, focusing on birds and humans. They discovered that two of the five mutations seen in the experimental viruses (from the Fouchier and Kawaoka labs) had occurred in numerous existing avian flu strains. Additionally, they found that a number of the viruses had both of the mutations.
Colin Russell, Royal Society University Research Fellow at the University of Cambridge, said: "Viruses that have two of these mutations are already common in birds, meaning that there are viruses that might have to acquire only three additional mutations in a human to become airborne transmissible. The next key question is 'is three a lot, or a little?' "
The scientists explored this key question using a mathematical model of how viruses replicate and evolve within a mammalian host and assessed the influence of various factors on whether the remaining three mutations could evolve in a single host or in a short chain of transmission between hosts
The factors that increased the likelihood of mutations evolving are:
1. Random mutation. The replication mechanisms of influenza viruses don't make perfect copies. On average, every time an influenza virus replicates itself it makes approximately one mutation somewhere in the genome of each new virus. In each infected human there will be billions of viruses, and thus with many viruses replicating, multiple mutations can accumulate within a single host. 2. Positive selection. If some of the remaining mutations help the avian virus to adapt to mammals, then those mutations will make the viruses more fit and thus will be positively selected and preferentially accumulate.
3. Long infection. The longer someone is infected and producing new viruses, the more time there is for mutations to accumulate.
4. Functionally equivalent substitutions. The sets of substitutions identified by Fouchier and Kawaoka are unlikely to be the only combinations of substitutions capable of producing an aerosol transmissible virus. The probability of emergence increases with the number of combinations.
5. Diversity in the within-bird virus population. Given all of the mutations there are likely to be within a host due to random mutation, it is possible that the viruses from a bird that infect a human might have a mutation that would not be detected by routine surveillance. For example, if 100 virus particles from a bird infect a human and one of those particles had a key mutation, it would increase the probability of the mutation reaching high levels within a host even though routine sequencing would not detect it.
6. Transmission between mammals. If mammals are capable of transmitting viruses that have some but not all of the necessary substitutions it could increase the probability of an airborne transmissible virus evolving.
The factors that decreased the likelihood of mutations evolving are:
1. An effective immune response. An effective immune response would shorten the length of an infection and thus decrease the time available to accumulate mutations.
2. Deleterious substitutions. If any of the substitutions necessary for airborne transmission were harmful to the virus it would, on average, slow the accumulation of mutations.
3. Order of acquiring mutations. It is not currently known if the mutations for airborne transmissibility need to be acquired in a specific order. If they do, it would, on average, slow the accumulation of mutations.
"With the information we have, it is impossible to say what the exact risk is of the virus becoming airborne transmissible among humans. However, the results suggest that the remaining three mutations could evolve in a single human host, making a virus evolving in nature a potentially serious threat," said Derek Smith, Professor of Infectious Disease Informatics at the University of Cambridge. "We now know that it is in the realm of possibility that these viruses can evolve in nature, and what needs to be done to assess the risk more accurately of these mutations evolving in nature."
The scientists recommend the following activities be considered high priority for estimating and ameliorating the risk of emergence of aerosol transmissible H5N1 viruses.
First, additional surveillance in regions where viruses with airborne transmission enabling substitutions have been observed and in regions connected to those regions by bird migration and trade. Also, increased surveillance for mutations that might have the same function as those found by the Fouchier and Kawaoka labs.
Second, related to surveillance, some targeted sequencing of H5N1 viruses should be done by "deep sequencing" where the lab sequences many viruses from an individual host to look for viruses that might have accumulated the critical mutations, even if those viruses are just a small proportion of the viruses within an animal.
Third, further investigations are needed to determine which substitutions and combinations of substitutions that are not the same as, but have the same function as, the substitutions identified by the Fouchier and Kawaoka labs are capable of making viruses airborne transmissible between mammals.
Fourth, further studies are needed to elucidate the changes in within-host fitness and between-host transmissibility associated with each airborne transmission enabling substitution and combination of substitutions.
Professor Smith added: "The situation is similar to assessing the risk of an earthquake or tsunami. We don't know exactly when and where, but by increasing monitoring and research – some of which is already underway – scientists and public health officials will be able to increase the accuracy with which the risk can be assessed and to minimise those risks.
The research was funded by multiple sources including the European Commission through framework 7 grants EMPERIE and ANTIGONE, the Royal Society, the Human Frontiers Science Program, and the National Institutes of Health.
May 29, 2012 - Identifying antimicrobial proteins in chickens that kill pathogens is one method being used by U.S. Department of Agriculture (USDA) scientists to find alternatives to the use of antibiotics to control infectious poultry diseases.
Each year, poultry diseases such as coccidiosis cause losses of more than $600 million in the United States and $3.2 billion worldwide.
Molecular biologist Hyun Lillehoj, at the Agricultural Research Service (ARS) Henry A. Wallace Beltsville Agricultural Research Center (BARC) in Beltsville, Md., has dedicated her career to discovering how to produce poultry without using drugs. Her research includes enhancing innate immunity through genetics, and examining molecules produced by birds in response to enteric or intestinal pathogens.
ARS is USDA's chief intramural scientific research agency, and this research supports USDA's priority of promoting international food security.
Some molecules are host antimicrobial proteins that can kill pathogens, improve immune responses and promote the growth of beneficial gut bacterial populations in poultry, according to Lillehoj, who works in the ARS Animal Parasitic Diseases Laboratory at BARC. She and her colleagues have identified one such immune molecule, called NK lysin.
Lillehoj and her colleagues demonstrated for the first time that NK lysin kills chicken coccidia. They also showed that this antimicrobial protein or host defense molecule is effective against other parasites such as Neospora and Cryptosporidia, which infect livestock and humans, respectively. One commercial company is looking at the possibility of developing NK lysin into a product that can be used to kill chicken intestinal parasites.
Lillehoj also is studying enteric bacterial infections caused by Clostridium, a pathogen associated with necrotic enteritis in poultry. She is using a similar molecular technology to develop alternatives to treat this disease.
Working with industry, international partners and other scientists, Lillehoj has discovered other options to antibiotic use in poultry. Phytochemicals derived from peppers, plums, safflower, green tea and other plants have been shown to be effective in enhancing the immune system of chickens. Also, the beneficial effects of probiotics, which are live, nonpathogenic bacteria that promote health and balance of the intestinal tract microbiota, have been demonstrated in past research.
Read more about this research in the May/June 2012 issue of Agricultural Research magazine.
May 22, 2012 - Hubbard recently held a successful GP Forum for some of their Classic and H1 customers from the Americas, Asia and the Middle East. This year Hubbard LLC hosted this important event between 23rd to 27th April at its USA production centre and the Sheraton Read House Hotel in Chattanooga.
Each morning presentations were given on different aspects of the management of Hubbard Grandparent Stock and technicians presented their individual experiences from around the world. On the final day there were presentations on nutrition, hatchery and hatch day breakout. The afternoon sessions were conducted at Hubbard's production facilities, which included visits to rearing and production Grandparent farms and to the Hubbard Grandparent hatchery in Pikeville, Tennessee with a capacity of 12 million breeders per year.
The unique mixture of both theory and practice was well received by the customers, who were able to see first-hand in the afternoon what was being described in the morning sessions.
In 2011 Hubbard celebrated its 90th anniversary. From the small flock of chickens with which Ira and Oliver Hubbard began the business in 1921, Hubbard has grown to one of the major international broiler breeding companies in the world. The poultry industry has seen remarkable changes during the past 90 years, with dramatic results for the benefit of humankind. Hubbard has played, and will continue to play, an important and vital role in this great industry
Oliver Hubbard's graduation from the New Hampshire Agriculture College in 1921 can been seen as the beginning of Hubbard in the commercial poultry business. From 1921 up to the acquisition by Merck in 1974, Hubbard has always been a family company. In 1997 Hubbard merged with the ISA-group from France, purely focusing on broiler breeding as from 2003. Since the French company Groupe Grimaud took over Hubbard from Merial in 2005 Hubbard is again part of a family company, which is the 2nd largest multi-species animal breeding company in the world, with a clear focus on the further development of Hubbard's business in the broiler industry around the world.
Hubbard provides solutions that focus on the economic performance, health and well-being of breeding stock. Hubbard specializes in state-of-the-art selection programs to improve the performance of their pure lines. It is essential to Hubbard to preserve a large gene pool offering more flexibility for innovative solutions to an industry facing more and more constraints being imposed to them:
- increased feed prices,
- animal welfare regulations,
- increased segmentation of the markets,
- and in some countries a reduction/shortage in production surface.
Hubbard operates its selection programs in 3 different R&D centres in North America and Europe, along with its own production sites in North America, Europe and Brazil. Hubbard has a longstanding experience in breeding, developing and marketing breeding stock for both conventional and alternative markets.
Presence in nearly 100 countries around the world and the support of dedicated teams involved in R&D, Production, Technical Service and Sales & Marketing assure the continuity to deliver quality products that are best suited to the different broiler markets throughout the world.
Hubbard is a company of Groupe Grimaud. For more information, please visit their website: www.hubbardbreeders.com
May 18, 2012 - Researchers at the Georgia Institute of Technology and the University of Georgia are exploring whether poultry vocalizations could give clues about their health and comfort.
According to an article on Science Daily, welfare of poultry (which is the top agricultural product in the state) is a high priority, and anything that can help producers determine the state of their flock means big business.
"Many poultry professionals swear they can walk into a grow-out house and tell whether a flock is happy or stressed just by listening to the birds vocalize," said Wayne Daley, a Georgia Tech Research Institute (GTRI) principal research scientist who is leading the research.
While there are lots of problems associating ith isolating specific vocalizations amongst a cacophony of noise, results do show that it is possible to gauge how birds are based on nothing but their vocalizations.
For more on this interesting research, read the article on Science Daily.
May 18, 2012 - Less than 10 years ago, the world marveled at the completion of the human genome project, which involved traditional technology to identify all the genes in a single organism—the human. Today, a more powerful technology is being used to detect thousands of organisms in an entire community.
Unlike traditional gene sequencing, the new molecular technique—metagenomics—eliminates the need to cultivate and isolate individual microbial species. Scientists can apply genomic analysis to mixed communities of microbes instead of to just one organism.
For example, researchers examining viral enteric (intestinal) diseases in poultry can take intestinal samples from different poultry flocks. The material can be processed to sequence all the viral nucleic acid—RNA and DNA—in the sample and then analyzed as a single genome.
Learning more about how genes interact is extremely important in the battle against enteric diseases for scientists at the Agricultural Research Service Southeast Poultry Research Laboratory (SEPRL) in Athens, Georgia. Disorders like poult enteritis mortality syndrome, poult enteritis complex, and runting-stunting syndrome cause diarrhea in birds, resulting in decreased weight, mortality, and increased production costs.
In studies of intestinal samples from turkeys with enteric diseases, ARS scientists have discovered a new virus that may have future antimicrobial applications.
Research has revealed that several viruses may be responsible for enteric diseases, yet a single causative agent has not been identified. Metagenomics research may help solve that mystery.
Scientists at SEPRL are using metagenomics to uncover vast amounts of known and previously unknown viruses in poultry. They have discovered and sequenced the complete genome of a new bacteriophage (phage) that might have future antimicrobial applications, described for the first time the complete genome of new chicken and turkey parvoviruses, and developed a PCR (polymerase chain reaction) test to detect these novel parvoviruses in commercial poultry flocks.
Unlocking a Treasure Trove
With help from industry producers and veterinarians, microbiologist Michael Day and research leader Laszlo Zsak, in SEPRL’s Endemic Poultry Viral Diseases Research Unit, collected intestinal samples from five different turkey flocks affected by enteric disease. To identify and characterize viruses using metagenomics, they prepared intestinal homogenates from the samples. The homogenates were filtered to remove larger constituents, like bacteria, and leave the smaller particles, like viruses. Metagenomics techniques were then used to sequence nucleic acid of all the RNA viruses present in the samples.
“I was expecting to find RNA sequences from viruses that had not been described before in the poultry gut,” Day says. “It turned out that there were quite a number of viruses in that particular sample.”
A comparison to similar viruses in computer databases showed that the intestinal virus metagenome contained thousands of pieces of nucleic acid representing many groups of known and unknown turkey viruses. Common avian viruses such as astrovirus, reovirus, and rotavirus were confirmed. Many RNA viruses, like members of the Picornaviridae family, were also detected.
Microbiologist Michael Day examines the validation results of a new molecular diagnostic assay for a turkey picobirnavirus. Day used a metagenomic approach to detect the novel picobirnavirus RNA in turkeys experiencing enteric (intestinal) disease.
An unexpected discovery was an abundance of previously unknown turkey viruses, such as picobirnavirus, a small, double-stranded RNA virus implicated in enteric disease in other agricultural animals, Day says. A calicivirus—the kind associated with human enteric diseases—was also identified in poultry.
Prospects of a Novel Phage
“Because metagenomics is so powerful, we generated and continued to analyze additional data from these samples and discovered a new bacteriophage,” Zsak says. “Until now, no one had described this kind of phage in turkey enteric samples.”
The virus, called “phiCA82,” belongs to a group known as “microphages” and is the type of virus that naturally kills bacteria, Zsak says. Phages are important because they can potentially be used as alternatives to antibiotics and as weapons against multi-drug-resistant pathogens.
Zsak and Day found a short sequence of the phage DNA and designed a technique to sequence its entire genome. Colleagues Brian Oakley and Bruce Seal, both microbiologists in the Poultry Microbiological Safety Research Unit of the ARS Richard B. Russell Agricultural Research Center, also in Athens, helped analyze the data. One task was to find out whether the new phage was related to similar viruses.
“That’s a question you would have with the discovery of any new kind of organism,” Oakley says.
Oakley downloaded all publicly available viral genome sequences and used bioinformatics—the application of computer science and information technology to the field of biology—to compare the newly discovered genome to previously discovered ones. The comparisons revealed that the new genome was unique.
“Future studies need to be completed to find out if phages like this actually kill the bacteria they infect,” Zsak says. “Once we can identify this mechanism, we can design identical ways to attack and kill these pathogens.”
Phages infect bacteria and then replicate, Seal explains. They do this by digesting the cell walls of bacteria.
“We are interested in being able to clone the gene that expresses enzymes that digest the cell wall,” Seal says. “If we can express those enzymes in an organism generally recognized as safe, like yeast for example, we can put them in feed to help reduce certain types of bacteria that cause disease.”
Chipping Away at Chicken Viruses
In earlier studies, Zsak and Day used metagenomics to identify and analyze the genome of a novel chicken parvovirus, ChPV ABU-P1.
“This was the first in-depth characterization and analysis of the full-length genome sequence of the chicken parvovirus,” Day says. “Comparisons were made to other members of the Parvovirinae subfamily that infect mammals and birds.”
Scientists also developed a PCR assay to detect the virus in turkeys and chickens and used the test to examine enteric samples collected from U.S. commercial turkey and chicken flocks across different regions.
“PCR proved to be highly sensitive and specific in detecting parvoviruses in both clinical samples from infected birds and field samples from turkeys and chickens with enteric diseases,” Zsak says.
Advantages of a Community Approach
The overall goal is to use metagenomics technology to develop and update diagnostic tools, identify effective new treatments, and improve management practices to help control costly animal and plant diseases, Day says.
The beauty of metagenomics is that viruses do not have to be isolated or identified. Small pieces of nucleic acid can be sequenced from samples taken from mixed communities—a process that allows scientists to discover new enzymes and proteins and look for genetic markers for disease-resistant traits or genes with possible antimicrobial applications.
“We need some way to understand a community and interrogate the nucleic acids in that community to see who’s there and what they’re doing,” Oakley says. “Are there pathogenic bugs in there? Are there genes associated with pathogenesis? Metagenomics does that.”—By Sandra Avant, Agricultural Research Service Information Staff.
This research is part of Animal Health (#103) and Food Safety (#108), two ARS national programs described at www.nps.ars.usda.gov.
To reach scientists mentioned in this article, contact Sandra Avant, USDA-ARS Information Staff, 5601 Sunnyside Ave., Beltsville, MD 20705-5129; (301) 504-1627.
May 16, 2012, Tallahassee, FL - Global Green, Inc. has announced that the Company has received the final report on the model Efficacy Study conducted on the Company's patented vaccine, Salmogenics, to be used to protect poultry from Salmonella bacteria. This study, conducted by AHPharma, an independent food safety and animal health research firm, is an important step towards receiving USDA approval for Salmogenics.
The Study was performed using 3,036 chickens, specifically broilers. Those chickens injected in ovo (in the egg before the chick is hatched) with Salmogenics showed a significant reduction in Salmonella bacteria.
The study reports that the "Salmogenics Vaccine appears to provide enough protection against all strains of Salmonella tested." Clearly, Salmogenics provided protection in broilers against the spread of Salmonella. The conclusion of the study reports that reducing Salmonella in chickens prior to them being processed and sold to the public is critical in reducing Salmonella levels.
"Our patented Salmogenics Vaccine is in the fourth and final phase required for USDA approval. The final report on the data in the Study conducted by AHPharma is very encouraging and will be forwarded to the USDA," commented Dr. Mehran Ghazvini, Chairman and CEO, Global Green, Inc.
Salmogenics Utilizes Unique Application
When Salmonella is discovered in the flock during the processing stage, the costs to eradicate the disease are staggering. Salmogenics is unique in that it is injected directly into the egg, before the chick is hatched, improving the immune system, health and welfare of the chicken. The vaccine reduces levels of Salmonella in the flock and reduces the risk of Salmonella contamination in the processing plant.
Leading Poultry Industry Expert Confirms Significance of Vaccine
The historic approach for Salmonella control ignores chicken live growing practices and attempts to completely eliminate Salmonella and other foodborne bacteria during final processing. A Salmonella vaccine addressing vigorous strains that are hard to destroy is important," commented James McNaughton, PhD, leading independent poultry research expert.
Global Green, Inc. plans to manufacture, market and sell the patented, exclusive, licensed vaccine known as the "Salmogenics Vaccine." Salmogenics was developed by Nutritional Health Institute Laboratories, LLC (a research affiliate and majority shareholder) to combat Salmonella bacteria in eggs and poultry. The vaccine is currently in the final stage of the USDA approval process. The Company has received approval from FINRA to begin trading publicly on the OTC market and has applied for DTC approval.
For more information, visit www.globalgreeninc.org.
Modern broiler breeder strains are simply too good at depositing breast muscle. Because they have a higher propensity to deposit muscle rather than fat, they may not have enough energy stored in the body to mobilize in times of energetic debt, and as a result these hens may have difficulty with early chick quality and long-term maintenance of lay. While the bird may still be able to transfer the necessary nutrients to the egg, with less energy available in storage, it will rely much more heavily on the feed it consumes each day to meet this need.
The concern is that the bird may carry additional breast muscle throughout life and, in order to maintain this high energy-demanding tissue, the hen will have to divert nutrients it might otherwise have been able to use to support egg production. In order to support egg production in broiler breeder stocks in the coming years, it may be time to question if current feed restriction methods and weight targets are as adequate now as when they were designed over 30 years ago.
Dr. Rob Renema and his research team at the University of Alberta have been exploring the concept of “composition restriction.” By manipulating the delivery of dietary energy and protein throughout the life of the bird, they hope to identify methods of feeding birds to a specific carcass composition rather than just to a target body weight. They theorize that this approach could discourage breast muscle deposition while providing for the energetic requirements of final maturation and early egg production.
Their findings? What you feed the birds during the growing phase has a greater effect on final carcass composition at the end of egg production than the diets fed during the egg production period do. Why? Primarily because muscle deposition is “set” when they are young, and this has a carry-over effect into the breeder phase. Feeding programs during the rearing or laying phase must not be designed in isolation.
Furthermore, growth was tied more closely to energy intake than to protein intake. Despite fairly similar energy intakes, however, energy was still one of the main factors affecting rate of lay. While maternal protein intake had very little effect on egg production, it did have the potential to affect broiler offspring yield and breast muscling – particularly in the males. To read more about this research project, please visit www.poultryindustrycouncil.ca.
By Tim Nelson, Executive Director
Recent events have shown us that people are so important to the poultry industry.
Our Research Day this year featured poultry health research. The focus was not only on disease research, but on the cost of disease to producers and industry as well. This was emphasized by having one Ontario producer tell attendees about his personal experience of managing a serious disease outbreak on his farm.
During the Research Day we recognized three eminent poultry researchers from the University of Guelph – Drs. Steve Leeson, Ian Duncan and the late Dr. Bruce Hunter – who dedicated their careers to poultry research.
The Poultry Industry Conference and Exhibition (known as the London Poultry Show) musters a veritable who’s who of the poultry service industry in Ontario and beyond. The mood that huge group brings for two days each year to the Western Fair District in London, Ont., to work (and play) together is palpable. What an intense and stimulating two days it is. The PIC brought a few guests in this year and they were blown away by the friendly, welcoming, open reception and hospitality they received at every booth. Great job, industry!
So, it was disappointing halfway through day 1 of the show to receive an e-mail from Dr. Fred Silversides, who conducts research into poultry genetics in B.C. (and whose research PIC supports), which said, “In August, my position will be cut as a result of the current round of deficit reductions, and AAFC (Agriculture and Agri-food Canada), is getting out of research in poultry genetic resources when it happens.”
We understand the federal and provincial governments are going through tough times. But this was the only centre where this type of research was being undertaken, and it had only one researcher and one student.
Not long after receiving this e-mail, the Agricultural Adaptation Council (AAC) informed me that the current Canadian Agricultural Adaptation Program (CAAP) will expire in March 2014, removing the need for regional councils (such as the AAC) in the delivery of any future federally funded programs.
Who made these decisions? Who knows – but they were made. How did we (industry) let it happen? Reading the e-mail made me reflect on how lucky we are to have the people at OMAFRA and AAFC here in Ontario who continue to support our programs of research and extension in an effort to ensure our industry’s sustainability. The Poultry Loading Decision Tree, Biosecurity Outreach Program, Growing Forward cost-share program and the upcoming PAACO (welfare auditing) course would not be possible without their support and that of industry and the University of Guelph.
Competition and risk management drives us to continue to develop new technologies, tools and management techniques. But what will keep this industry sustainable are the very visible personal connections, relationships, networks and collaborations that bind it together and make it successful.
Somehow in B.C. the industry lost a connection. We have great connections in Ontario, but we need to work at them.
Make sure your connections extend to our government and university partners and at every opportunity thank them for the funds and people they provide.
The board of directors of the Canadian Poultry Research Council (CPRC) continues to make changes as part of its efforts to make CPRC the most efficient and effective organization possible. For example, research grant procedures have undergone changes that the board believes will better align research activities with industry’s goals.
The New System
The new system of receiving and reviewing research grant proposals uses a two-step process: 1) an industry review of Letter of Intent (LOI); and 2) a scientific review of methodology. In the LOI, the applicant is asked for an overview of the proposed research as well as an account of how the research will impact the poultry industry. For example, how will the proposed work help industry reach its Research Target Outcomes? The applicant is asked to think about where the proposed research fits in to the so-called “innovation continuum”; is it primary research directed at a fundamental understanding of how something works, or is it of a more applied nature? Who are the ultimate end-users of the research and what would it take to bring it to the adoption stage? Answers to these questions will help CPRC assess the potential benefits of the proposed research.
The completed LOIs, due June 1, will be evaluated by the CPRC board and support staff with help from additional scientific experts.
Successful applicants will be invited to submit a Detailed Proposal (step 2 of the process) that provides particulars on experimental design and proposed methodology. The proposal will list members of the research team and describe their expertise and the roles each will play in the proposed work. Training of highly qualified personnel (students, research technicians, etc.) will also be described, as will specifics of proposed expenditures and funding sources.
The Detailed Proposals will be reviewed by CPRC’s Scientific Advisory Committee (SAC), the members of which represent a breadth of knowledge and expertise that can accurately assess the intricacies of the proposed methodology. Applicants will have an opportunity to address issues or concerns raised during the SAC review before a final funding decision is made by the CPRC board.
CPRC’s funding commitment is contingent on the proposal securing matching funds from another source(s). The preference is that funds from the poultry sector (CPRC and other sources) be matched at least 1:1 with funds from outside the poultry sector (e.g., other agricultural sectors, the private sector, the government, etc.). Part of CPRC’s service is to help researchers identify and secure matching funds. Matching the poultry sector’s investment in research with funds from other sources maximizes the impact of that investment and encourages collaboration with organizations that might not otherwise directly support poultry research.
Although it will increase the time between LOI submission and final approval, the CPRC board believes the new system will benefit both industry and researchers by improving communication and ensuring research is targeted at industry goals. The new process will be monitored and assessed on an ongoing basis to ensure it continues to increase CPRC’s effectiveness.
The ‘New’ Board
The new granting procedures were approved in principle by CPRC’s board of directors at the March 23, 2012, annual general meeting. CPRC is pleased to announce that all directors, who represent each of the organization’s five members, were re-elected without change to positions. Jacob Middelkamp, representing Chicken Farmers of Canada, returns as CPRC chairman. Middelkamp is a broiler chicken producer in Alberta. Roelof Meijer, representing Turkey Farmers of Canada, returns as vice-chairman. Meijer is a turkey producer also from Alberta. The Canadian Poultry and Egg Processors’ Council (CPEPC) is represented by Erica Charlton, CPEPC’s technical director. Cheryl Firby, director of agricultural operations at Maple Leaf Foods, represents the Canadian Hatching Egg Producers, and Helen Anne Hudson, director of corporate social responsibility for Burnbrae Farms, represents Egg Farmers of Canada. CPRC would like to take this opportunity to thank these individuals and their respective organizations for their past efforts and continuing support. The continuity of the CPRC board will facilitate ongoing efforts to enhance poultry research in Canada.
The membership of CPRC consists of the Chicken Farmers of Canada, the Canadian Hatching Egg Producers, the Turkey Farmers of Canada, the 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. CPRC’s contact information is available at www.cp-rc.ca.
The Poultry Industry Council recently held a “Science in the Pub” seminar that aimed to challenge current knowledge about cleaning and disinfecting poultry barns, and how these processes may be affecting the birds’ immunity and ability to handle pathogens.
Dr. Shayan Sharif, an immunologist with the Department of Pathobiology at the University of Guelph’s Ontario Veterinary College, began the evening meeting with a discussion on how the environment influences a chicken’s immune system.
The immune system of a chicken or turkey is affected by the presence of pathogens (bacteria, protozoa, fungi, viruses), how the birds are managed, and the genetics of the bird (host). To manage the health of the chicken’s immune system, an equilibrium must be achieved between the host, the environment and a disease-causing pathogen, he said. If anything tips the balance of this equilibrium, infection and disease are the result.
He believes the environment the birds are raised in is having a significant impact on the virulence of pathogens and how they impact health.
He used two well-known poultry diseases as examples. When it was first described in the 1940s, Marek’s Disease (caused by a virus) had rather mild symptoms, said Sharif. However, by the 1960s, the disease had become much more serious – its virulence had increased – and the disease began affecting different biological systems within the bird. He believes the cause of this is the change in the environment the birds were raised in over this time period.
Sharif noted that Jungle Fowl can harbour a lot of coccidia (the protozoa that cause coccidiosis) without getting very sick or dying. He said these birds can also harbour multiple strains of coccidia, and that some of these strains are not found here in North America. He said that this is evidence that Jungle Fowl and coccidia have evolved together, and that there may be some benefit to the bird from this relationship. He argued that some protozoa and bacterial species may actually assist the bird by enhancing its immune system.
He said that the immune system of modern chickens is actually shrinking, as research has shown a reduction in the quantity of immune cells, such as T cells and B cells, produced in the thymus and bursa respectively. It’s known that this decrease has something to do with the birds’ diet, but genetics is also likely playing a role, he said. The environment is also key – although some growth in the immune system occurs pre-hatch, much of the development takes place in the four to eight weeks following hatch.
Sharif pointed to the “hygiene hypothesis” of how, in western societies, there has been an increase in autoimmune diseases because people living in these countries are living in too clean an environment, thus reducing their exposure to potential pathogens early in life, which weakens their immune system. Sharif questions whether or not the poultry industry is causing the same issues with the birds by placing them in too clean an environment.
By not exposing them to pathogens early on, he feels that this may be causing immunosuppression, reducing a chick’s ability to handle the stressors (such as suboptimal brooding, transport to the farm, nutritional challenges, temperature fluctuations, etc.) that it will be exposed to.
He also pointed out that the chick’s early immunity can be influenced by the use of ionophores, probiotics and antibiotics, which all impact the microflora of the gut, where immune cells are also produced. Probiotics have been shown to have a positive influence on this microflora, he said.
Dr. Jean-Pierre Vaillancourt from the University of Montreal was the second speaker of the evening. He said that many researchers around the world believe that keeping a barn too clean isn’t necessarily a good thing, and that it’s probably a good idea for birds to be challenged early to enhance their immunity.
However, he noted that just how clean the environment should be before birds are placed is highly dependent on the country involved and its view on cleaning and disinfection protocols. How these processes are performed is also key, he said. Perceived failures in removing pathogens from the barn are often the result of cleaning failures.
Vaillancourt gave an overview of his experience consulting in France, where the protocol is to be “super clean.” In France, there is a total down time of two weeks from shipping to chick placement. This includes a thorough cleaning and disinfection of the barn and equipment, a period of time to let the barn dry, and then a second disinfection.
This protocol is more extreme than what is used in the U.S., where the strategy is “different situations require different tools,” he said. The U.S. also considers the cost-benefit of certain practices, he said. Although performing a second disinfection is a good idea scientifically, it may not be economical, he said. Canada is somewhere “in between” France and the U.S., he said.
Having worked in North Carolina, Vaillancourt said when he was first asked to go to France to consult on sanitation, he wasn’t sure he would be of benefit. However, he said that although they were “super clean,” it did not necessarily correlate with a reduction or a decrease in the persistence of a pathogen in the barn. “I’m not saying it’s not worth cleaning and disinfecting, but we do not necessarily need to imitate others,” he said.
He pointed to a research study conducted in France examining the persistence of salmonella in barns. He said that when no disinfection took place, the risk of salmonella in a subsequent flock was eight times greater than if two disinfections had taken place, and if only one had been performed, the risk was six times greater. The use of antibiotics in the previous flock resulted in a threefold increase, and if rodents were not controlled, the risk was nine times greater.
What’s important is how the barn is cleaned prior to disinfection, and keeping the barn dry during the down time, he said. Optimal cleaning requires mechanical action, pressure, a detergent used at the right concentration, and adequate contact time. Temperature of the water is also important, he said. Between 45 and 60 C is ideal, anything over 60 C, and “you are just baking the organic material and providing any potential pathogens with a coating,” he said.
In France, microbial monitoring is used to measure how “clean” a barn is. Vaillancourt said a researcher decided to compare a visual assessment of organic matter present after cleaning to microbial counts measured on swabs of the barn environment. Vaillancourt said that interestingly, there was very little relationship between how clean a barn “looked” and how clean it really was.
“Dryness is your friend, it’s the enemy of pathogens,” he said. If there is going to be a longer down time between flocks, as long as the barn is dry, this shouldn’t be a problem. If the barn is humid, pathogens start to multiply. “Use ventilation and heat to ensure that the barn is dry,” he said.
The importance of cleaning can also be seen in a 2006 study performed in Canada. Vaillancourt said the study, which looked at different building materials (wood, plastic and metal) and the type of cleaner used (water, iodine, or a foam or gel detergent) showed that the type of surface didn’t matter when it came to cleaning, but the method used was important. Iodine did not perform well, and the gel detergent resulted in a lower bacterial count than that of the foam because it increased contact time, he said. Dry cleaning (removal of dust and dirt without water) was best for wood, and wet cleaning was best for plastic and metal.
“What’s important is how the surface you are dealing with is cleaned, and how dry it is,” he said. “You may be surprised to see that what you have been doing may not be working as well as you think.”
On May 8, 2012, the Poultry Industry Council (PIC) held its Spring Symposium (formerly known as Research Day) celebrating the career of three distinguished poultry researchers, as well as highlighting research regarding poultry health and disease that it helps fund.
The day began with the presentation of the Poultry Worker of the Year Award to Ian Duncan, who did groundbreaking work on laying hen welfare, and poultry nutrition researcher Steve Leeson. Also honoured was the late Bruce Hunter, a much beloved teacher and researcher from the Ontario Veterninary College. Each award was preceded by a short video featuring colleagues and peers discussing their accomplishments and significance to the field. All of the honorees were emotional and extremely thankful, none more so than Bruce Hunter’s widow, who was noticeably incredibly touched by the kind words said.
The rest of the day was comprised of researchers discussing various aspects of poultry health and disease, beginning with Jean-Pierre Vaillancourt from the University of Montreal, who discussed putting disease into perspective.
Vaillancourt stated that animal loss due to disease is a continuous and significant problem that claims a large number of animals each and every year. Inside the poultry system, he said, diseases constantly change and adapt and therefore it is a constant battle between management and prevention.
He also said that as density continues to increase, productivity would continue to decrease because production diseases and infection pressure will rise. “The potential costs are huge if we are unprepared,” he said, “and can have major effects on human health as well.”
The second speaker at the symposium was Cindy-Love Tremblay, a PhD student at the University of Montreal working on antimicrobial resistance in birds and how normal gut flora could aquire resistance. Her results have shown that healthy poultry could be a reservoir for resistance genes, which could quickly spread throughout a population of bacteria.
While the research is only in its early stages, Tremblay said that future work could be used to help reduce resistance by decreasing the ability for the bacteria to exchange genes.
Shayan Sharif from the Ontario Veterinary College at the University of Guelph followed with an explanation on the potential uses of probiotics in humans, as well as poultry. According to him, the use of a combination of probiotics in chickens can help modulate the immune response, increase weight gain, improve feed conversion and decrease both mortality and overall parasite/bacteria load.
This was demonstrated in tests with a cocktail of three different probiotic bacteria, and the researchers found that they can help enhance the chicken’s immune response. Research is also being done on the potential antibacterial properties of probiotics with a new cocktail of five different probiotics targeted against a specific strain of Salmonella
Ben Wood, a geneticist from Hendrix Genetics then took to the podium to discuss the challenges associated with selecting for specific traits in turkeys. He said that screening for metabolic disorders with a genetic basis are quite effective, but artificially selecting against behavior and pathogen resistance is more difficult.
The reason for this is because, by selecting for improved resistance, Wood says that the results visibly decrease the presentation of commercially viable traits, such as growth rate and feed conversion. “And until breeders get the word that consumers are willing to pay for less product, “ said Wood, “things aren’t going to change.”
The final scientific presentation was by Michele Guerin from the University of Guelph on the prevalence of Salmonella serovars in breeder flocks in Ontario. The results showed that there was a seasonal difference between Salmonella’s presence in breeders (more pronounced in the fall) and hatcheries (summer), and that the best way to eliminate an outbreak is constant monitoring at the breeder flock and hatcheries across all poultry types. She noted that if she and her research team could gain a better understanding of why these seasonal patterns occur, they could design studies that could show how these infections could be prevented.
Len Jewitt, owner of BLT Farms Inc., a turkey, egg and broiler operation north of Guelph, ended the day with an emotional presentation on the impact of disease at the farm level. Several years ago, one of his layer barns was found to be positive for Salmonella Enteritidis (SE), and he explained that there are many costs to the producer when disease strikes, and these go beyond dollars and cents.
The biggest challenge was the mental cost. “This is something that as an industry, we don’t want to talk about,” he said.
He said the positive result made him feel “like a loser,” and he asked himself what had gone wrong, as he and his employees had been so clean and had followed all necessary protocols. Since the SE occurrence, he says he “is on pins and needles when a swab is taken to see if I’m OK for another year. I’m shooting at something I can’t understand, and praying it won’t hit me.”
He finished his talk with a piece of advice for those who are responsible for going on the farm and beginning the depopulation and disinfection process — to use a gentle hand. “Remember you are walking into someone’s dreams,” he said.
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