|HRISTOV, ALEX - Pennsylvania State University|
|HANIGAN, MIKE - Virginia Polytechnic Institution & State University|
|Todd, Richard - Rick|
|MCALLISTER, TIM - Agri Food - Canada|
|NDEGWA, PIUS - Washington State University|
|Rotz, Clarence - Al|
Submitted to: Journal of Animal Science Supplement
Publication Type: Abstract Only
Publication Acceptance Date: 12/15/2010
Publication Date: 8/15/2011
Citation: Hristov, A., Hanigan, M., Cole, N.A., Todd, R.W., McAllister, T., Ndegwa, P., Rotz, C.A. 2011. Nutrition - An effective tool for mitigating ammonia emissions from dairy and feedlot operations [abstract]. Journal of Animal Science Supplement 89, E-Suppl. 2:143-144.
Technical Abstract: Ammonia emitted from animal feeding operations is a potential environmental and human health hazard, contributing to eutrophication of surface waters and nitrate contamination of ground waters, soil acidity, and fine particulate matter formation. It may also contribute to global warming through nitrous oxide formation. Thus, reducing ammonia emissions from dairy and beef cattle operations is critical to achieving environmentally sustainable animal production that will benefit producers and society at large. Ammonia emission factors and flux rates are extremely variable. For example, dairy farms emission factors from 0.82 to 250 g ammonia per cow per day have been reported, with an average of 59 g per cow per day (n = 31). Ammonia flux rates for dairy farms averaged 1.03 g per m**2 per hour (n = 24). In contrast, ammonia losses are greater from beef feedlots, where emission factors average 119 g per animal per day (n = 9) with values as high as 280 g per animal per day. Ammonia flux rate for beef feedlots averaged 0.174 g per m**2 per hour (n = 12). Using nitrogen (N) mass balance approaches, daily ammonia N losses of 25 to 60% of the N excreted in manure have been estimated for dairy cows and feedlot cattle. Practices to mitigate ammonia emissions include reducing excreted N (particularly urinary N), acidifying ammonia sources, or binding ammonium to a substrate. Reducing crude protein concentration in cattle diets and ruminal protein degradability are powerful tools for reducing N excretion, the ammonia-emitting potential of manure, and whole-farm ammonia emissions. Decreasing dietary crude protein concentration may reduce the ammonia emitting potential of manure by up to 40 to 50%. Reducing dietary crude protein can also benefit the producer by reducing feed cost. These interventions, however, have to be balanced with the risk of lost production.