大蒜素和茶皂素对肉羊气体代谢及甲烷排放的影响

Effect of Allicin and Tea Saponin on Gas Metabolism and Methane Emission in Mutton Sheep

本试验旨在研究肉羊饲料中添加天然植物提取物大蒜素(allicin,AL)和茶皂素(tea saponin,TS)对肉羊气体代谢及甲烷排放的影响,并筛选出抑制甲烷效果最佳的添加剂量。选取15只年龄相近、体况良好、体重为(60.0±1.73)kg的杜泊绵羊(♂)×小尾寒羊(♀)杂交F1代肉用成年母羊,以大蒜素和茶皂素为添加剂,其中大蒜素添加水平分别0.5、1.0、1.5、2.0、2.5 g/(只·d),茶皂素添加水平分别1.6、2.0、2.4 g/(只·d)。试验分为1个对照期和2个试验期,每期采用单因素试验设计,在限饲基础日粮的基础上分别饲喂不同的植物提取物,采用Sable开路式循环测热系统进行气体代谢试验。结果表明:大蒜素在添加量为2.0 g/(只·d)时可明显降低单位代谢体重在每千克干物质采食量下的甲烷排放量(P>0.05);茶皂素在添加量为2.0 g/(只·d)时,显著降低单位代谢体重在每千克干物质采食量下的甲烷排放量(P<0.05),分别降低甲烷排放量6.38%和9.57%。天然植物提取物大蒜素和茶皂素可以在一定程度上影响肉羊CO2排出量并降低甲烷排放量。大蒜素、茶皂素的最适添加量均为2.0 g/(只·d)。

This study was conducted to investigate the effect of dietary supplementation of Allicin （AL） and Tea saponin （TS） on gas metabolism and methane emission on mutton sheep,with an aim to determine the optimum supplementation level.Fifteen healthy dorper （♂） × Small-tailed Han （♀） crossbreed ewes （F1） with average body weight of 60.0± 1.73 kg were selected.Initially ten ewes were used to determine the baseline gas emission.Then two experiments were conducted and in each experiment the ewes were randomly allotted to five supplementation levels （0.5,1.0,1.5,2.0,and 2.5 g/d for AL and 1.6,2.0,and 2.4 g/d for TS） of three animals each.Open-cycle Sable calorimetry system was used for gas metabolism test.The results showed that supplementation of 2.0 g AL （P＞0.05）and 2.0 g TS （P＜0.05） significantly decreased 6.38％ and 9.57％ methane emission calculated based on dry matter intake （CH4 L/kg W0.75）,respectively,compared with the baseline group.Both AL and TS can reduce the CO2 and methane emission and the optimum supplementation level should be 2.0 g/d and 2.0 g/d respectively.