2008 - 2010

Impact of ammonia on welfare of laying hens, and implications for the environment

Principal Investigator: Steve Leeson and Tina Widowski, University of Guelph
Status: Completed


Atmospheric ammonia is known to impact bird health and that of poultry workers. Ammonia is a breakdown product of uric acid, which is the main nitrogenous component of avian urine. Consequently, the more uric acid excreted, the greater the potential for ammonia release. To date, the main mechanism to control environmental ammonia levels in layer barns has been by adjustment to the ventilation air flow. There is now concern about the contribution of animal agriculture to ammonia release into the atmosphere, and so this option is likely going to be curtailed and/or regulated in the near future. The goal of this research program is to quantitate ammonia release from caged layers relative to various nutritional and intervention strategies and assess layer welfare in terms of any physiological changes to the bird, as well as test the layers voluntary aversion to, or acceptance of, graded levels of atmospheric ammonia.


$458,499 (CPRC $51,118, NSERC/AAFC $305,666, Novus $60,000, Ajinomoto $41,715)

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