【作者】 崔英才； 林雪彦； 苏鹏程； 王中华；

【Author】 CUI Ying-Cai;LIN Xue-Yan;SU Peng-Cheng;WANG Zhong-Hua;College of animal science, Shandong agricultural university;

【机构】 山东农业大学动物科技学院；

【摘要】 (目的)康奈尔净碳水化合物和蛋白质体系(CNCPS)采用析因法预测小肠可消化氨基酸流量,是目前较为完备的小肠可消化氨基酸预测体系。该体系通过不同溶剂溶解,将饲料蛋白质分为5种组份(A、B1、B2、B3和C),其中C组份为酸不溶性氮,被认为在瘤胃中不能降解且在小肠中不能消化,对小肠可消化氨基酸没有贡献。有研究表明,CNCPS所定义的C蛋白组份有可能在小肠中消化,本研究从奶牛场采集了10种饲料样品,测定了其C组份的瘤胃降解率和原料及12h瘤胃降解残渣的C组份小肠消化率。小肠消化率测定采用体外法。研究结果表明,10种饲料C蛋白组份的瘤胃降解速度常数kc在0.25～3.89%/h之间,与B3蛋白组份在相似的范围内;饲料原料C蛋白组份小肠消化率在0～81.61%之间,饲料原料12h瘤胃降解残渣C蛋白组份小肠消化率在0～44.25%之间,表明不同饲料原料及饲料原料与12h瘤胃降解残渣之间的C蛋白组份小肠消化率存在差异,部分饲料具有很高的C组份小肠消化率,不能忽略。本研究结果说明CNCPS定义的C蛋白组份在瘤胃中可以降解,且部分饲料具有很高的小肠消化率,应考虑C组份对小肠可消化氨基酸流量的贡献。更多还原

【Abstract】 The Cornell net carbohydrate and protein system(CNCPS) predict absorptive amino acids in ruminant small intestine by a factorial method, which is the most theoretically sound predicating system at present. CNCPS fractionate protein in feedstuffs by different detergents into five components(A, B1, B2, B3, and C). C component is the acid detergent insoluble protein, which is believed undegradable in the rumen and indigestible in the small intestine and hence has no contribution to small intestine amino acid flow. Previous studies reveled that C component might be digestible in the small intestine. To evaluate the concept, ruminal degradability and small intestine digestibility of C component in the raw materials and 12h ruminally degraded residues of 10 feed samples collected from different dairy farms were analyzed in the present study. The results indicated that ruminal degradability rate coefficients kc of C component ranged from 0.25%/h to 3.89 %/h, which was similar to that of B2 component. The small intestine digestibility of C component in raw material ranged from 0% to 81.61% and that in 12h residue ranged from 0% to 44.25%. The digestibility of some feedstuff was too high to be negligible. It was concluded that C protein component was degradable in the rumen and those escaped rumen degradation might have high digestibility in the small intestine. The contribution of C component to absorptive amino acid in small intestine should be considered.更多还原