估测饲料蛋白质瘤胃降解率活体外新方法的研究

A NEW IN VITRO PROCEDURE FOR ESTIMATION OF RUMINAL PROTEIN DEGRADATION

研究了一种新的根据活体外人工瘤胃产气量与游离 NH_3-N 量估测反刍动物饲料蛋白质瘤胃降解率的方法。饲料样本与瘤胃液在活体外培养6 h,其产气量与组入瘤胃微生物蛋白质中的NH_3-N 量呈高度正相关(r>0.99),故产气量可用于准确度量组入微生物蛋白质中的 NH_3-N量。以饲料样本的游离 NH_3-N 量与根据产气量估测的组入 NH_3-N 量之和占其总 N 量的比例,作为其瘤胃蛋白质降解率的度量。本研究方法简单、快速、成本低,所测结果与体内法结果具有高度相关性(r>0.97)。

A new in vitro procedure for estimation of ruminalprotein degrada- tion was established by measurements of 6-hour gas production and free NH_3-N concentration of ruminant feedstuffs when they were incubated with rumen liquor-buffer solution.A linear regression between NH_3-N incorporated into microbial proteins(y,mg)and gas production(x,mL)was found to be highly significant(r>0.99),indicating that the gas production of a feed can be regar- ded as a more accurate estimate of the incorporated NH_3-N.The free NH_3-N plus the incorporated NH_3-N represented the N degraded from the sample.The ruminal protein degradabilities of 14 feed samples tested by this simple in vitro procedure were highly correlated(r>0.97)with those by in rive procedure.