Project Number: 6209-31630-002-28
Project Type: Reimbursable

Start Date: Sep 01, 2008
End Date: Aug 31, 2009

Objective:
To determine, in cooperation with scientists from Texas AgriLife Research, Kansas State University (KSU), West Texas A&M University (WTAMU), and Texas A&M University (TAMU), atmospheric ammonia and methane concentrations and emissions at commercial beef cattle feedyards and to determine the effects of environmental and management factors on these emissions.

Approach:
Ammonia emissions will be measured at two commercial beef cattle feedyards in Texas using open path lasers and a backward Lagrangian Stochastic model. Methane emissions will be measured from the retention pond and pen areas of one commercial feedyard using the same methodologies. Nitrogen and carbon balance will be determined based on chemical composition of diets, fresh feces, aged manure, and animal weight gain. Effects of environmental factors, pond chemistry, pen surface chemistry, and management factors on emissions will be monitored. A respiration calorimetry system will be constructed to measure enteric and metabolic methane, carbon dioxide, ammonia and hydrogen sulfide flux from cattle. These data will potentially be used to develop, improve, and/or verify statistical and process-based models of ammonia and methane emissions. Potential methods to decrease ammonia emission will be studied using lab-scale and small plot-scale studies. Ammonia emissions from pen surfaces treated with varying chemicals will be measured using flow through lab chambers or a static chamber on feedlot plots.