Authors : Sang-Moon Lee, Jin-Suk Jeong, Sang-Cheol Lee, Kyu-Hyun Park and Seongwon Seo
Abstract: Methane, one of the major greenhouse gases is produced primarily from cattle among livestock. Many researches have been conducted to reduce methane production and also to develop methods and/or equations to predict methane production in cattle. The objectives of this study were thus to construct a database containing experimental observations of methane production from cattle and to develop equations that predict methane production by cattle accurately. The database developed in this study contains experimental observations from the research articles published in the Journal of Dairy Science, Journal of Animal Science, Animal Feed Science and Technology, Canadian Journal of Animal Science, International Congress Series and Journal of Nutrition from 1964 till 2009. A total of 350 treatment means from 75 studies were obtained from the scientific journal articles that were found by searching for with methane and cattle as keywords. There were different methods measuring methane production; a chamber system, indirect respiratory hood, Sulfur hexafluoride (SF6) and stoichiometric calculation. Only measured data were used in the subsequent analysis. Consequently the actual database used for the analysis is composed of a total of 256 treatment means from 57 studies. The types of animal in the database were 110 lactating dairy cows, 12 non-lactating dairy cows, 47 heifers, 65 steers, 10 calves, 10 bulls and 2 mixed. The mean (±SD) methane (g day-1) methane (Mcal day-1) and methane (GE%) of the data were 204.50 (±104.22), 2.76 (±1.38) and 5.56 (±1.87), respectively. Among the variables tested, DMI (kg) or NDF intake (NDFI, kg) was the most significant single variable that correlates with methane production. Using a random coefficient model with study as a random effect, researchers obtained -24.27 (±17.76) + 13.93 (±1.68) DMI (kg) + 0.57 (±0.20) FpDM + 8.43 (±4.16) NDFI (kg) (n = 145, -2 Res log likelihood = 1434.9) for predicting methane production (g). Using a simple linear regression, the best equation was CH4 (g) = –18.53 (±14.90) + 11.89 (±1.50) DMI (kg) + 0.49 (±0.18) FpDM + 14.19 (±3.77) NDFI (kg) (R2 = 0.84, root mean square error = 42.25). Although, DMI and NDFI are inherently correlated, a single variable was not sufficient to explain the variations in methane production of cattle. When both NDFI and DMI were present in the model statement type of animal or method of methane measurement was no longer significant. The results from this study suggest that methane production from cattle can be predicted accurately with DMI and NDFI. More research however is needed to improve accuracy of the model predictions.
Sang-Moon Lee, Jin-Suk Jeong, Sang-Cheol Lee, Kyu-Hyun Park and Seongwon Seo, 2012. Prediction of Ruminal Methane Production from Cattle. Journal of Animal and Veterinary Advances, 11: 3228-3233.