康奈尔净碳水化合物-蛋白质体系预测小肠可消化粗蛋白质含量

Predicting Utilizable Crude Protein Content in Small Intestine by Cornell Net Carbohydrate and Protein System

本试验旨在建立奶牛饲料的康奈尔净碳水化合物-蛋白质体系(Cornell net carbohy-drate and protein system,CNCPS)预测小肠可消化粗蛋白质(uCP)含量的数学模型。采用CNCPS体系对13种饲料蛋白质组分进行划分,采用移动尼龙袋法测定13种饲料小肠uCP含量,试验动物为3头带有永久性瘤胃瘘管和十二指肠瘘管的荷斯坦奶牛,采用单因素试验设计。结果表明:1)豆粕、棉籽粕、菜籽粕、葵花籽粕、芝麻粕、玉米胚芽粕、米糠、米糠饼、米糠粕、大麦、麦麸、玉米和玉米麸质饲料的uCP含量分别为390.32、321.90、297.21、230.50、388.62、177.49、85.53、116.78、134.74、80.47、128.26、70.28和66.65g/kg。2)所有试验饲料实测uCP含量与CNCPS各蛋白质组分含量的回归方程为:uCP=-4.11+6.48 PA+7.73 PB1+5.72 PB2+8.26 PB3+5.11 PC(R2=0.997 2,P<0.01);蛋白质饲料实测uCP含量与CNCPS各蛋白质组分含量的回归方程为:uCP=12.79+5.47 PA+7.04 PB1+9.74 PB2+8.14 PB3(R2=0.998 7,P<0.01);能量饲料实测uCP含量与CNCPS各蛋白质组分含量的回归方程为:uCP=14.80+8.55 PA+6.27 PB2+17.64 PB3(R2=0.987 4,P<0.01)。3)蛋白质饲料、能量饲料及所有试验饲料的实测uCP含量与CNCPS各蛋白质组分含量的相关系数均高于0.95,蛋白质饲料实测uCP含量与CNCPS各蛋白质组分含量的相关系数高于能量饲料。结果提示,利用CNCPS体系划分的各蛋白质组分含量预测饲料uCP含量是可行的,且预测蛋白质饲料的uCP含量比预测能量饲料的uCP含量更准确。

This study was conducted to establish mathematical models of predicting utilizable crude protein(uCP) content in feed for dairy cows using Cornell net carbohydrate and protein system(CNCPS).Contents of protein fractions of 13 kinds of common feeds were analyzed using CNCPS,and uCP of feeds was determined using mobile nylon bag method,and three Holstein dairy cows with permanent ruminal and duodenal cannulas were used in a single factor experimental design.The results showed as follows: 1) contents of uCP in soybean meal,cottonseed meal,rapeseed meal,sunflower seed meal,sesame meal,corn germ meal,rice bran,rice bran cake,rice bran meal,barley,wheat bran,corn and corn gluten feed were 390.32,321.90,297.21,230.50,388.62,177.49,85.53,116.78,134.74,80.47,128.26,70.28 and 66.65 g/kg,respectively.2) The regression equation of contents of measured uCP and CNCPS fractions in all experimental feeds was uCP=-4.11+6.48PA+7.73PB1+5.72PB2+8.26PB3+5.11PC(R2=0.997 2,P<0.01);the regression equation of contents of measured uCP and CNCPS fractions in protein feed was uCP=12.79+5.47PA+7.04PB1+9.74PB2+8.14PB3(R2=0.998 7,P<0.01);the regression equation of contents of measured uCP and CNCPS fractions in energy feed was uCP=14.80+8.55PA+6.27PB2+17.64PB3(R2=0.987 4,P<0.01).3) Regression coefficients(R2) between CNCPS fractions contents and measured uCP contents in protein feed,energy feed and all experimental feed were all higher than 0.95,and regression coefficient between measured uCP content and CNCPS fractions contents in protein feed was higher than that in energy feed.In conclusion,it is feasible that using contents of protein components subdivided by CNCPS to predict uCP content,and the prediction result in protein feed is more accurate than that in energy feed.