Over the past decade, Canada’s chicken sector has significantly reduced its use of antibiotics, eliminating 2 key classes that are essential to human medicine. Ongoing efforts now aim to cut the remaining use while keeping birds healthy, offering lessons for poultry producers worldwide.
For some time, in the chicken sector in Canada and elsewhere, 2 classes of antibiotics that are also used in human healthcare were administered to chickens to protect them from bacterial diseases, thus improving overall bird health.
Feed additives suppport antibiotic reduction
However, these groups, known as Category I and II antibiotics, have been completely phased out in Canada. Steve Leech, Director of Food Safety and Animal Health at Chicken Farmers of Canada (CFC), explains that CFC’s reduction strategy has involved education and communicating lessons learned from antibiotic reduction experiences and working with the supply chain to examine changes in management practices.
“A focus of attention has been examining different feed and water additives, for example, probiotics, essential oils, etc., and vaccines that can help reduce antimicrobial use. These trials continue, as the environmental and growing conditions across Canada require solution-specific responses.”
In addition, through the implementation of the CFC’s ‘Responsible Antimicrobial Use Strategy,’ only antibiotics approved by Health Canada are used by broiler producers. This has helped to reduce antimicrobial resistance (AMR) in various bacteria, an issue which clearly prevents serious risks of facing untreatable diseases.
Role of bacitracin in feed
Category III antibiotics have been treated differently, for good reason. By the end of 2020, the preventative use of this class of antibiotics (with only one of them used in Canadian broiler production, Bacitracin) was mandated to end. However, CFC, in collaboration with experts, backed away from that approach. Bacitracin is important to prevent serious bird health issues, and its use not only protects their welfare but also prevents the need for additional antimicrobial interventions.
Currently, the preventive use of Category III antimicrobials is not regulated, explains Leech, but CFC continues to move forward with a use-reduction strategy. “Recently, CFC convened a focus group of members from across the supply chain to explore options and opportunities for Category III reduction within a non-regulatory approach,” he reports.
“Nutritionists, vets, farmers, researchers and representatives from the hatchery, processing and pharmaceutical sectors met several times to share knowledge and experiences, developing recommendations on ways to move forward.” These recommendations are wide-ranging. They include increased communications to farmers, vets, and nutritionists, working with the federal government to increase access to alternatives, stewardship of Category III antibiotics, and improved management throughout the supply chain. Leech says CFC is currently evaluating the recommendations and determining the best paths forward for implementation.
Feed components and disease pressure
This approach is supported by Dr Babak Sanei, Associate Director for Poultry and Aquaculture at Zoetis Canada. “There are varying bacterial disease pressures across different regions of the country, influenced by factors such as flock density and dietary components, particularly wheat inclusion, which can impact the incidence of disease,” he explains.
“Additionally, Infectious Bursal Disease (IBD), a common immunosuppressive viral condition in chickens, is present throughout Canada and may reduce birds’ ability to cope with even mild gut challenges. In such scenarios, especially in the absence of in-feed antibiotics like Bacitracin, the likelihood of resorting to water-based treatments with Category 2 antibiotics increases.”
Tracking feed antibiotics reduction
Over the last few years, the successful implementation of CFC’s ‘Responsible Antimicrobial Use Strategy’ has been monitored and reported through 2 organisations which track antimicrobial use and AMR at the farm level, but also the processing and retail levels. One is the Canadian Integrated Program for Antimicrobial Resistance Surveillance (CIPARS). The other is the Public Health Agency of Canada (PHAC), which runs multiple programmes and also provides both an AMU Dashboard and an AMR dashboard to view data.
By 2023, data analysis shows that at least 60% of the total antibiotics volume applied to Canadian broiler flocks are not those used in human health (they are instead Category IV antibiotics and chemical coccidiostats). Leech says CIPARS reports indicate this is currently still the case.
Feed-related outcomes and challenges
In addition, over 40% of Canadian broiler flocks are being produced without Category III antibiotics. All AMU indicators (for example, mg/PCU, mg/kg animal biomass) have decreased, along with AMR metrics in bacteria of particular concern. Indeed, Leech notes that PHAC reports a decrease in resistance across most antimicrobials in response to the industry’s recent policies. Resistance in some bacteria isolated from chickens has declined in some cases by 38%.
Leech also adds that “CIPARS reports continue to demonstrate the positive impact of CFC’s Category I preventive use elimination on E. coli and Salmonella resistance at farm, slaughter and at retail,” noting that E. coli is an indicator organism for AMR due to its ability to readily acquire resistance and spread it. He adds that “while there are many factors that drive resistance observed at retail, there has also been a significant decrease in multi-drug resistance patterns observed at retail since 2018 in E. coli isolates.”
CFC and Canadian chicken farmers hope to share further progress in the future. Sanei adds that there are several alternative products to antibiotics now available on the market, each offering varying levels of efficacy and cost-effectiveness. These include a vaccine for Necrotic Enteritis.
However, at the same time, he says it is important to recognise that product performance can be influenced by external factors such as the severity of coccidiosis, the presence of concurrent immunosuppressive diseases and also a barn’s microenvironment. “These pressures can sometimes lead to inconsistent or less predictable outcomes,” Sanei notes, “even with otherwise-promising solutions.”
