【作者】 张英学；

【导师】 王中华；

【作者基本信息】 山东农业大学 ， 动物营养与饲料科学， 2007， 硕士

【摘要】 本试验研究以康奈尔净碳水化合物和蛋白体系(CNCPS,Cornell Net Carbohydrate and Protein System)采用的对粗蛋白质和碳水化合物各组分的分析方法为基础,对山东省奶牛养殖中常用的部分饲料原料进行取样分析,分别利用瘤胃尼龙袋法和体外透析酶解法测定这些常用饲料原料的各蛋白质组分的降解速率和小肠消化率,得出这些饲料蛋白各组分的瘤胃降解常数和小肠消化常数。并对CNCPS体系中小肠氨基酸流量的预测模型做了一些改进,建立了更加科学的预测小肠氨基酸流量的模型。本试验主要分下面三部分进行研究。试验部分一:瘤胃蛋白质降解动力学及过瘤胃蛋白预测模型的研究。选用3头体重(BW)为483±21kg,泌乳日龄(DIM)为175±6d,健康且装有永久性瘤胃瘘管(Bardimon Inc.Parma,ID)的荷斯坦奶牛。用瘤胃尼龙袋法对山东省常用的十五种奶牛饲料进行营养价值评定,并测定了蛋白质各组分(A、B1、B2、B3、C)的含量;利用瘤胃尼龙袋法测定了这些饲料原料的的降解速率,得出了这些饲料干物质和粗蛋白可降解各组分(B1、B2、B3)的瘤胃降解参数;建立了预测饲料蛋白各组分(B1、B2、B3)瘤胃降解参数的方法。试验部分二:过瘤胃蛋白质在小肠中的降解动力学及小肠可吸收蛋白预测模型的研究。用具有半透膜性质的透析管模拟动物肠道消化吸收的生理环境,以活性稳定的酶制剂代替奶牛小肠液,测定试验一得到的不同时间点瘤胃降解残渣的小肠消化率,并用数据拟和法求出不同饲料各组分的小肠消化率。结果发现通过数据拟和得到的组分B2、B3小肠消化率的数值与CNCPS模型中相应组分小肠消化率的实测值基本相同。CNCPS模型认为C组分不能被动物消化,本试验结果表明某些饲料部分C组分可以被动物消化。所以在预测小肠氨基酸流量时应考虑C组分对小肠氨基酸流量的贡献。试验部分三:饲料蛋白各组分氨基酸组成的研究。CNCPS在预测饲料小肠氨基酸流量时将饲料蛋白各组分的氨基酸构成视为相同。本研究测定了六种饲料的蛋白各组分(B1、B2、B3、C)的比例及氨基酸的构成,发现各组分的氨基酸组成差别较大,在预测过瘤胃饲料蛋白(REFAA)时应分别计算饲料蛋白各组分对小肠氨基酸的贡献。因此建议过瘤胃饲料蛋白对小肠氨基酸贡献量的预测方程由CNCPS中的: REFAAi =∑AAINSPij×0.01×(REPB1j + REPB2j + REPB3j + REPCj)改为:REFAAi =0.01×∑(AAB1ij×REPB1j + AAB2ij×REPB2j + AAB3ij REPB3j + AACij×REPCj)更多还原

【Abstract】 Carbohydrate and protein fractions and their digestion rates of cow feed in shandong province were determined in this study based on the method in cornell net carbohydrate and protein system model(CNCPS).Besides, we find there have something to be improved in cornell net carbohydrate and protein system.Then we modified the model in some aspects.Experiment part one: Study on digestibility kinesics protein in rumen and Predictive model of rumen undegraded protein.Studies were conducted with three healthy dairy cows with permanent rumen cannulas, conform milk yield and lactation in initial stages.fifteen cow feedstuff nutritional values were evaluated with rumen nylon bag method.Besides this trail determin the ratio of every protein fractions and ruminal degradation rates of protein fractions of B1、B2 and B3 of 15 feedstuffs for dairy cow. Througe this experiment,we developed an predictive method of ruminal degradation rates of every protein fractions.Experiment part two: Study on digestibility kinesics of ruminal undegraded protein in small intestine and predictive model of small intestine absorbable proteinA pepsin-pancreatin in vitro method using dialysis tube was studied to measure digestibility value of the residues after rumen.and small intestine digestibility of every protein fractions were predict ed with an curve fitting system. The results indicated that the predicitive values of protein fractions of B1、B2 and B3 were same as the values which CNCPS were used. Througe the experent ,we found that protein faction C coule be digestied in some feedstuff of the fifteen feedstuff ,but in In cornell net carbohydrate and protein system model, faction C was be thought coule not be digestied by cows .So a more mechanistic approach is needed predict intestinal digestion of the residues after rumen.Experiment part three: study on amino acid composition of every protein fractionsIn cornell net carbohydrate and protein system model,same essential amino acid composition of protein fractions B1、B2and B3 is used to calculate supply of amino acid of RUP. This trial determined amino acid composition of protein fractions B1、B2、B3andC,great differences were found among these protein fractions.These differences woule serious influence the accuracy of the model. A more mechanistic approach is needed to take palace the approach of cornell net carbohydrate and protein system.更多还原