Submitted to: American Dairy Science Association (ADSA) - American Society of Animal Science (ASAS) Joint Annual Meeting
Publication Type: Abstract Only
Publication Acceptance Date: 4/21/2016
Publication Date: 7/19/2016
Citation: Neel, J.P., Turner, K.E., Gowda, P., Steiner, J.L. 2016. Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2)emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma USA. American Dairy Science Association (ADSA) - American Society of Animal Science (ASAS) Joint Annual Meeting. 94, E-Suppl. 5/J:287-288.
Technical Abstract: Effect of frame size and season on enteric methane (CH4) and carbon dioxide (CO2) emissions in Angus brood cows grazing native tall-grass prairie in central Oklahoma, USA J.P.S. Neel USDA ARS, El Reno, OK A reduction in enteric CH4 production in ruminants is associated with improved production efficiency. Enteric CH4 and CO2 production associated with the livestock industry is of interest due to the impact these emissions might have on global climate change. Our objective was to evaluate the effect of cow frame size and season on enteric CH4 and CO2 production in cattle grazing during summer and fall. Twenty eight Angus cows (BW: 545 ± 49 kg) grazing native tall-grass prairie in central Oklahoma, USA, were utilized to estimate individual enteric CH4 and CO2 production (via a commercially available breath analyzer). Cow frame size was categorized based on frame scores (FS) generated from individual hip heights. Summer and fall season designations were based on summer and winter solstices, and the fall equinox. . Large-frame cows were heavier (P<0.001) and had a greater FS (P<0.001) compared to medium-frame (609 vs 480 kg, and 6.8 vs 4.6 respectively) Large-frame cows produced calves with heavier (P<0.01) 205 d adjusted weaning weights (261 vs 222 kg). There were no frame size by grazing season interactions. Large-frame cows produced greater (P<0.001) enteric CH4 (280 vs 248 g/d) and CO2 (9065 vs 8021 g/d) than medium. Cows produced higher (P<0.001) amounts of enteric CH4 and CO2 in summer than in fall (292 vs 236 g/d, and 9065 vs 8021 g/d respectively). When expressed as total production of CH4 or CO2 per weight unit of weaned calf, enteric gas production did not differ between FS types (0.20 and 6.5 kg/kg respectively). Further research is needed to relate enteric gas production to herbage nutritive value and animal DM intake. Keywords: Native prairie, enteric methane, beef cows, gazing