新疆南疆地区肉羊常用精饲料体外产气量与有效降解率的相关性分析

Correlation Analysis Between in Vitro Gas Production and Effective Degradation Rate of Common Concentrates for Mutton Sheep in Southern Xinjiang

本试验分析了新疆南疆地区肉羊常用精饲料体外产气量与有效降解率的相关性,旨在寻找肉羊常用精饲料干物质有效降解率的简易评价方法。以新疆南疆地区肉羊常用的6种蛋白质饲料和7种能量饲料为试验材料,采用体外产气法与人工瘤胃持续发酵法,在测定产气量(GP)与干物质有效降解率的同时,分析二者之间的相关性及常规营养成分对干物质有效降解率的影响,建立了以GP、常规营养成分预测干物质有效降解率的模型。结果显示:1)潜在产气量及8、16、24、36、48 h产气量均与干物质有效降解率呈正相关关系(P<0.05);以相关性最强的3个预测值潜在产气量及24和36 h产气量为预测因子,分别建立干物质有效降解率的预测模型,其决定系数(R^2)分别为0.553、0.613和0.612。2)饲料常规营养成分含量与干物质有效降解率的相关性分析结果中,干物质有效降解率与饲料中性洗涤纤维(NDF)含量呈显著负相关关系(P<0.05),与饲料酸性洗涤纤维(ADF)含量呈极显著负相关关系(P<0.01);建立以ADF、NDF含量预测饲料干物质有效降解率的一元、二元预测模型,二元预测模型[EDIVDM D=88.481-0.484ADF-0.231NDF(P<0.01)(EDIVDM D为干物质有效降解率)]R^2最高,为0.855。综合得出,体外产气法可以代替尼龙袋法预测肉羊常用精饲料的干物质有效降解率,可对饲料的降解性能做出快速、合理、有效的评价;利用饲料中的纤维含量来预测其他主要营养物质在瘤胃内降解率的方法切实可行。

In order to explore the simple method for evaluating effective degradation rate(ED)of dry matter(DM)of concentrate,the correlation analysis between in vitro gas production(GP)and ED of common concentrates for mutton sheep in southern Xinjiang was carried out.Six kinds of protein feedstuffs and 7 kinds of energy feedstuffs were used as experimental material.GP and ED of DM were detected by in vitro GP method and continuous artificial rumen fermentation method.In the meantime,the effects of common nutrients on ED of DM as well as the correlation between GP and ED of DM were analyzed.Estimation models based on GP and common nutrients to predict ED of DM were established.The results showed as follows:1)potential GP and 8,16,24,30,36 and 48 h GP had positive correlations with ED of DM(P<0.05);the correlation efficiencies of prediction models of ED of DM based on potential GP,and GP at 24 and 36 h were higher,and the coefficients of determination(R 2)were 0.553,0.613 and 0.612,respectively.2)In results of correlation analysis between common nutrient contents and ED of DM,ED of DM had significantly negative correlations with neutral detergent fiber(NDF)(P<0.05)and acid detergent fiber(ADF)contents(P<0.01);single factor and two factors estimation models for ED of DM were established based on ADF and NDF contents,and the two factors estimation model[ED IVDMD=88.481-0.484ADF-0.231NDF(P<0.01,R 2=0.855)(ED IVDMD was ED of DM)]had higher R 2.In conclusion,in vitro GP method can replace the nylon bag method to estimate ED of DM,and make a quick,reasonable and effective evaluation on the degradation characteristic of common concentrate feedstuffs for mutton sheep;fiber content in feedstuffs can be used to predicate degradation rate of other main nutrients in rumen.