CRPC Update: March 2011
The agricultural sector is a contributor to ammonia emissions in Canada,
whether from animal agriculture or its use as fertilizer. The Canadian
Environmental Protection Act (CEPA) designates several contaminants
associated with ammonia as “toxic substances.” Under the Act, the
federal government is required to manage these substances.
The agricultural sector is a contributor to ammonia emissions in Canada, whether from animal agriculture or its use as fertilizer. The Canadian Environmental Protection Act (CEPA) designates several contaminants associated with ammonia as “toxic substances.” Under the Act, the federal government is required to manage these substances. Although there are no regulations in North America on ammonia emissions, regulations are being drawn up in the United States, and it may be that Canada is not far behind. The poultry industry has funded research in order to identify the sources of ammonia, determine its scope and effects and develop strategies to decrease emissions and/or their impact.
Dr. Steve Leeson at the University of Guelph has been studying ammonia emissions from layer hens over the past three years. This research considers the effects of ammonia on the health and welfare of the birds as well as strategies that might be used to reduce its emission.
Ammonia in the barn
Ammonia levels in commercial layer barns can range from five to 30 parts per million (ppm). Exposure to ammonia levels at the high end of this range can cause nose and throat irritation in humans. Dr. Leeson’s preliminary results indicate that layer hens are not averse to 20 ppm ammonia and that ammonia levels typically found in commercial barns do not cause undue stress to the birds. However, ventilation air exhausted from the barns does contain ammonia and efforts are underway to find ways to reduce this source of emission.
Lowering crude protein
Since virtually all ammonia originates from nitrogenous compounds in feed, lowering crude protein (CP) is one way to reduce ammonia emissions. Dr. Leeson and his group fed laying hens diets ranging from 20 per cent CP down to 10 per cent CP. Results clearly showed that reducing dietary nitrogen leads to reduced nitrogen in the manure, which in turn results in less microbial conversion to ammonia. For the diets used in this study, CP levels of less than 15 per cent began to result in decreased egg size and body weight. As CP dropped even lower, certain amino acids were found to be deficient and had to be added back to maintain egg numbers. While lowering CP is an effective way to decrease ammonia emissions, fine-tuning low CP diets requires a better understanding of the efficiency at which layer hens can utilize free amino acids as compared to intact proteins from ingredients such as soybean meal.
Feed additives
Dr. Leeson also tested three commercially available feed additives for their ability to reduce ammonia emissions. The first was a natural charcoal derived from oak trees that has been shown to adsorb a range of chemicals. When added to feed at a rate of 3 kg/1,000 kg, the product resulted in a small reduction of ammonia emissions. The second product, a saponin derivative from the yucca plant, resulted in 10-24 per cent reduction in ammonia emissions when added to the feed at a rate of 0.5 kg/1,000 kg. The third product, also derived from the Yucca plant, resulted in even greater reduction of ammonia. Supplementing feed with this product at 0.5 kg/1,000 kg resulted in a 50 per cent reduction of ammonia emissions, which translates into an estimated 3,000 kg of ammonia per 100,000 layers annually.
Dr. Leeson’s work complements steps others in Canada and abroad are taking towards an overall approach to reduce ammonia emissions. Funding for this research was provided by CPRC, Novus International Inc. and Ajinomoto Heartland LLC in partnership with the Natural Engineering and Research Council (NSERC) and Agriculture and Agri-Food Canada (AAFC).
For more details on any CPRC activities, please contact Gord Speksnijder at The Canadian Poultry Research Council, 483 Arkell Road, R.R. #2, Guelph, Ontario, N1H 6H8, phone: (289) 251-2990, fax: (519) 837-3584, email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it , or visit us at www.cp-rc.ca.
The membership of the 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.
Dr. Steve Leeson at the University of Guelph has been studying ammonia emissions from layer hens over the past three years. This research considers the effects of ammonia on the health and welfare of the birds as well as strategies that might be used to reduce its emission.
Ammonia in the barn
Ammonia levels in commercial layer barns can range from five to 30 parts per million (ppm). Exposure to ammonia levels at the high end of this range can cause nose and throat irritation in humans. Dr. Leeson’s preliminary results indicate that layer hens are not averse to 20 ppm ammonia and that ammonia levels typically found in commercial barns do not cause undue stress to the birds. However, ventilation air exhausted from the barns does contain ammonia and efforts are underway to find ways to reduce this source of emission.
Lowering crude protein
Since virtually all ammonia originates from nitrogenous compounds in feed, lowering crude protein (CP) is one way to reduce ammonia emissions. Dr. Leeson and his group fed laying hens diets ranging from 20 per cent CP down to 10 per cent CP. Results clearly showed that reducing dietary nitrogen leads to reduced nitrogen in the manure, which in turn results in less microbial conversion to ammonia. For the diets used in this study, CP levels of less than 15 per cent began to result in decreased egg size and body weight. As CP dropped even lower, certain amino acids were found to be deficient and had to be added back to maintain egg numbers. While lowering CP is an effective way to decrease ammonia emissions, fine-tuning low CP diets requires a better understanding of the efficiency at which layer hens can utilize free amino acids as compared to intact proteins from ingredients such as soybean meal.
Feed additives
Dr. Leeson also tested three commercially available feed additives for their ability to reduce ammonia emissions. The first was a natural charcoal derived from oak trees that has been shown to adsorb a range of chemicals. When added to feed at a rate of 3 kg/1,000 kg, the product resulted in a small reduction of ammonia emissions. The second product, a saponin derivative from the yucca plant, resulted in 10-24 per cent reduction in ammonia emissions when added to the feed at a rate of 0.5 kg/1,000 kg. The third product, also derived from the Yucca plant, resulted in even greater reduction of ammonia. Supplementing feed with this product at 0.5 kg/1,000 kg resulted in a 50 per cent reduction of ammonia emissions, which translates into an estimated 3,000 kg of ammonia per 100,000 layers annually.
Dr. Leeson’s work complements steps others in Canada and abroad are taking towards an overall approach to reduce ammonia emissions. Funding for this research was provided by CPRC, Novus International Inc. and Ajinomoto Heartland LLC in partnership with the Natural Engineering and Research Council (NSERC) and Agriculture and Agri-Food Canada (AAFC).
For more details on any CPRC activities, please contact Gord Speksnijder at The Canadian Poultry Research Council, 483 Arkell Road, R.R. #2, Guelph, Ontario, N1H 6H8, phone: (289) 251-2990, fax: (519) 837-3584, email: This e-mail address is being protected from spambots. You need JavaScript enabled to view it , or visit us at www.cp-rc.ca.
The membership of the 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.