Project Number: 6209-31630-003-32
Project Type: Reimbursable

Start Date: Oct 01, 2010
End Date: Feb 28, 2013

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

Approach:
Ammonia emissions will be measured at several commercial beef cattle feedyards and dairies 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 feedyards 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 used to measure enteric and metabolic methane, carbon dioxide, ammonia and hydrogen sulfide flux from cattle. These data have value for development, improvement, and/or verification for statistical and process-based models of ammonia and methane emissions. Potential methods to decrease ammonia emissions 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 chember on feedlot plots.