Title: Ammonia emissions from open lot dairies: lessons learned from beef cattle feedyards Authors
Submitted to: Western Dairy Air Quality Symposium
Publication Type: Proceedings
Publication Acceptance Date: March 22, 2013
Publication Date: N/A
Interpretive Summary: Open lot dairies are much like beef cattle feedyards. Much of what we know about ammonia loss from feedyards can be applied to open lot dairies. Methods that estimate ammonia loss in feedyards can be used in open lot dairies. The advantages, disadvantages and appropriateness of a method must be carefully considered. When we plan a study or want to evaluate another study, it is useful to consider several points. These include using mass balance checks, being aware of biological and physical limits of a system, using multiple methods, and comparing results with other studies. We can never know what the real, exact ammonia loss from a dairy is. However, we can fine-tune our estimates using the tools of science, so that we approach the real ammonia loss.
Technical Abstract: Open lot dairies share more similarities with open lot beef cattle feedyards than with closed dairy housing. The well-developed understanding of ammonia loss from feedyards can inform our study of open lot dairies by recognizing differences and similarities and then apply what we have learned. Methods used to quantify ammonia emissions from beef feedyards are applicable to open lot dairies. Each method has its advantages and disadvantages and a method’s appropriateness to a given situation must be carefully evaluated. When planning an emissions study or when evaluating other studies, there are several guiding criteria that give us the best chance of accurately defining emissions from an animal production system like an open lot dairy. These include mass balance constraints, biological and physical limits, use of multiple methods, and comparative integrity of studies. We don’t have a magic bullet methodology that will give us actual emissions. What we have is the scientific method, carefully and continually applied, which yields a steadily more refined understanding of reality.