CPRC Update: Researchers study ammonia mitigation strategies
Exposure could adversely affect bird welfare.
Commercial poultry operations can contribute significantly to the atmospheric burden of ammonia, which is considered to be detrimental to both human and animal health as well as the environment. Ammonia, the major noxious gas associated with poultry manure, is produced from microbial decomposition of nitrogenous compounds.
Poultry are exposed to manure and manure gas through three exposure routes: inhalation; oral; and through the skin – all of which could adversely affect bird welfare. Thus, the objective of this research is to evaluate control strategies that may reduce atmospheric release of ammonia from commercial poultry operations and investigate the effects of manure on bird health and welfare.
AMMONIA MITIGATION STRATEGIES
Dr. Bill Van Heyst and his research team at the University of Guelph are studying control strategies that may reduce atmospheric releases of ammonia from commercial poultry operations. The objective of this research is to determine the most efficient methods in which poultry operations can control their emissions of ammonia to improve in-barn air quality and limit emissions to the atmosphere.
To accomplish this evaluation of control strategies, they measured ventilation rates and concentrations of ammonia in addition to production performance. To date, the researchers have evaluated the use of water sprinklers and poultry litter treatment. Studies using a centralized air exchange system are ongoing.
Poultry litter treatment was found to be an effective control strategy to reduce emissions of ammonia. Initial reductions in ammonia emissions immediately after poultry litter treatment application were found to be 72 per cent. The overall average reduction in ammonia emissions was found to be 57 per cent, lasting 11 days on average. Results from the water sprinkler campaign were inconclusive due to confounding factors in the barn. Preliminary evidence thus far suggests that the centralized air exchanger better controls the litter quality with lower moisture content and that this reduces ammonia production.
WELFARE IMPACT OF AMMONIA
Dr. Alexandra Harlander, also from the University of Guelph, and her team are conducting research to evaluate the effects of manure on bird welfare. They conducted a series of experiments to examine the both short and long-term implications of exposure to manure.
The team sought to: investigate how exposure to ammonia affects foraging and avoidance behaviour in birds; analyze whether different levels of airborne ammonia are affecting the birds preference for feeding time and duration; examine whether birds avoid foraging in areas with manure present; determine the relative preference for clean or dirty scratch pads of birds; determine whether low nitrogen-containing diets increase the risk and incidence of fatty liver hemorrhagic syndrome and trigger behavioural impairment; and evaluate whether birds prefer clean feed versus feed mixed with excreta, and how a likely choice affects problem solving behaviour.
To date, the researchers have investigated all objectives and a data analysis is ongoing. However, preliminary results obtained to date show that: birds were able to discriminate between artificial and natural ammonia sources; number of manure belt operations did not affect the number of feeding events; birds have a relative preference for clean litter over litter substrate that has been present for the entire duration of their lives; birds visited more frequently and spent more time on dirty rather than clean scratch pads; and feeding nitrogen-reduced diets adversely impacted behavioural and/or cognitive abilities in birds.
THE NEXT STEP
These projects are ongoing and will be completed in early 2018. Completion of the data analyses will fully explain the short and long-term implications of exposure to manure on poultry welfare. It will also determine the most efficient methods in which poultry operations can control their emissions of ammonia to improve in-barn air quality and limit emissions to the atmosphere.
This research is funded by CPRC/AAFC under the Poultry Science Cluster Program, OMAFRA, Wheeden Environments and Egg Farmers of Canada.
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.