Title: Seasonal methane emissions from a beef cattle feedyard on the U.S. southern High Plains Authors
Submitted to: Meeting Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 23, 2013
Publication Date: June 24, 2013
Citation: Todd, R.W., Cole, N.A. 2013. Seasonal methane emissions from a beef cattle feedyard on the U.S. southern High Plains.5th Greenhouse Gases and Animal Agriculture Conference, June 23-26, 2013, Dublin, Ireland. Advances in Animal Biosciences, Cambridge University Press, 4(2):504. Interpretive Summary: Cattle produce methane, a powerful greenhouse gas that adds to global warming. As more cattle are grown in feedyards, it is important to increase our understanding of methane produced by cattle production. This knowledge will help to better predict methane emissions and to meet the demands of potential regulations. We studied a commercial feedyard in the Texas Panhandle during winter and summer. Methane loss was twice as much in winter as summer when expressed on the basis of how much feed cattle ate; in winter, 18.5 grams of methane were lost for every kilogram of dry feed consumed, and in summer 9.3 grams of methane were lost for every kilogram of dry feed consumed. On a per animal basis, methane loss was 145 grams per day in winter and 79 grams per day in summer. Calculated on a yearly basis, 41 kilograms of methane were emitted for each animal in the feedyard. These results will help researchers or regulators who are calculating national inventories of methane emission.
Technical Abstract: Cattle are a significant source of methane (CH4), a potent greenhouse gas that contributes to global warming. As cattle production systems intensify, a better understanding of CH4 emissions from cattle feedyards is needed to build more accurate emission inventories, help develop better predictive models, and meet potential regulatory requirements. Our objective was to continuously quantify seasonal CH4 emissions from cattle and corrals during winter and summer at a typical beef cattle feedyard on the southern High Plains of Texas, USA. We worked at a commercial feedyard in the Texas Panhandle. Methane emissions from the feedyard, including enteric and manure sources, were quantified using open path laser spectroscopy and and inverse dispersion analysis during 32 days in winter and 44 days in summer, 2010. Cattle production data such as population and dry matter feed intake (DMI) were also collected. Winter daily CH4 loss (18.5 g CH4/kg DMI) was twice that in summer (9.3 g CH4/kg DMI). On a per capita basis, CH4 emission averaged 145 g/animal/d during winter and 79 g/animal/d during summer. These values were well within the values reported in other studies. During a 24-h period, in both seasons, emissions showed a bimodal distribution, with peaks at mid-morning and early evening. Annualized per capita emission rate was 41 kg/animal/yr.