牛甲烷排放量的估测

Estimation of Methane Emissions by Cattle in China

反刍动物甲烷排放量的研究主要是根据能量转化过程中甲烷能量损失量来确定饲料的代谢能和能量需要。但由于甲烷是温室气体的一种来源,其排放量的增加致使全球气温升高。因此,近些年来国内外学者对反刍动物甲烷排放量的估测越来越重视。研究方法大多根据反刍动物甲烷排放量的实测结果,运用统计方法建立甲烷排放量的估测模型。本文重点介绍中国农业大学以瘤胃瘘管阉牛作为试验动物,用大型自控呼吸测热室持续测定不同日粮在全消化道内甲烷排放量所得出的估测模型。根据《奶牛营养需要和饲料成分》(2007)中现有参数,选用上述估测模型进行甲烷排放量的估测。其中,由于我国存栏产奶奶牛的平均产奶量较低,故估测的甲烷排放量为96.29 kg/(头.a)。但日产奶量为20 kg/头的奶牛其甲烷排放量估测值为114.6 kg/(头.a)。此外,本文还利用上述模型对我国肉牛、役牛和牦牛的甲烷排放量作了初步估测。

The assessment of methane emissions by cattle were generally for the study of energy metabolism,but the methane is one of the major sources of anthropogenic greenhouse gas emission in the world and we should pay more attention to estimate the methane emissions with the models by former research results of energy metabolism in cattle with different diets using automated respiration large chambers sited in China Agricultural University(CAU).The required parameters for calculation could be searching in nutritional allowances and feed composition for dairy cattle(2007).Methane emissions have been assessed using the CAU model.The emission averaged 92.29 kg CH4/cow/year with lower milk yield,but the emission of the higher yielding herd with 20 kg milk/cow/day was 114.6 kg CH4/cow/year.The methane emissions of draught cattle and yaks were also assessed by the CAU models.