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ARS Home » Midwest Area » Lexington, Kentucky » Forage-animal Production Research » Research » Publications at this Location » Publication #314045
Title: Evaluation of a rapid determination of heat production and respiratory quotient in Holstein steers using the washing rumen technique

Author
item KIM, DO HYUNG - University Of Kentucky
item MCLEOD, KYLE - University Of Kentucky
item Klotz, James
item KOONTZ, ANNE - University Of Kentucky
item FOOTE, ANDREW - University Of Kentucky
item HARMON, DAVID - University Of Kentucky

Submitted to: Kentucky Beef Report
Publication Type: Experiment Station
Publication Acceptance Date: 9/1/2012
Publication Date: 1/1/2014
Citation: Kim, D., Mcleod, K.R., Klotz, J.L., Koontz, A.F., Foote, A.P., Harmon, D.L. 2014. Evaluation of a rapid determination of heat production and respiratory quotient in Holstein steers using the washing rumen technique. Kentucky Beef Report. pgs. 26-28.

Interpretive Summary: Accurate measurement of the factors contributing to maintenance energy expenditures and to efficiencies of energy use for maintenance is a necessary part of developing an understanding of the animal’s energy economy. This study evaluated the use of the washed rumen technique for measurement of various aspects of an animal’s basal metabolic rate. Emptying the rumen presents the unique characteristic of shutting down the main source of energy into the animal in minutes. Therefore, the washed rumen technique may permit determination of accurate estimates of the energy required for maintenance within shorter time periods (8 to 24 hours) than traditional fasting approaches, and this approach may provide an alternative to the traditional 48 h fasting time, or measurements made during the third and fourth day of starvation. This study is a critical improvement in the animal welfare of energy metabolism research. If researchers have access to ruminally-cannulated animals, then research can be performed that would have previously required 2 to 4 days of animal starvation.

Technical Abstract: The objective of this study was to validate use of the washed The objective of this study was to validate use of the washed rumen technique for rapid measurement of fasting HP and RQ. The plateau of RQ values was 0.87 ± 0.01 and 0.72 ± 0.01 for unwashed and washed rumen, respectively. The RQ decreased to approximately 0.7, 8 h after washing the rumen. Mean RQ after washing rumen were 0.78, 0.74, and 0.73 (SEM = 0.01) for time segments 0 to 8 h, 9 to 16 h, and 17 to 24 h, respectively. Mean fasting HP after washing rumen was 18.75, 16.84, and 16.72 (SEM = 0.35) kJ/(h·kg0.75) for time segments 0 to 8 h, 9 to 16 h, and 17 to 24 h, respectively. There were no significant differences in RQ and fasting HP (P = 0.225 and P = 0.810, respectively) between the time segment of 9 to 16 h and 17 to 24 h. Thus, an accurate measurement of fasting HP can be obtained using a shorter-term measurement with the washed rumen technique. This approach provides an alternative to the traditional 48 h fasting time, or measurements made during the third and fourth day after starvation.