Modification and evaluation of a ruminant emission measurement system for assessing cattle metabolism

Abstract

Respiratory gas exchanges may be monitored to assess heat production as an indication of metabolic performance. A Ruminant Emission Measurement System (REMS) was initially constructed to measure methane emission from cattle, and is located at the Beef Cattle and Sheep Field Laboratory, the University of Illinois at Urbana-Champaign. REMS was modified to expand the capacity for measuring heat production, and methods for verifying system reliability were applied. Three recovery test approaches (alcohol combustion method, constant gas injection method, and gravimetric gas injection method) revealed opportunities for improving the system performance by reducing the impact of systematic errors. Approaches for the application of REMS were also explored to reduce the measurement variability be identifying an appropriate acclimation period for cattle.