摘要
采用尼龙袋消化试验研究大豆皮替代产奶牛日粮中玉米与小麦麸对瘤胃干物质与纤维消化特性的影响。试验处理为大豆皮分别替代精料中 0 (对照 ) ,2 5% ,50 % ,75%和 10 0 %玉米与小麦麸的 5个替代水平的产奶牛饲粮。饲粮的精料和粗料比为 50∶ 50。利用 2头装有永久性瘤胃瘘管的本地黄牛测定 5种大豆皮替代水平饲粮的干物质 (DM)和中性洗涤纤维 (NDF)的尼龙袋消化率与动态消化参数。所用数学模型为 :Y=a+b(1- e-c(t-L ) )。大豆皮 DM与 NDF的每小时消化速度分别为 0 .0 72和 0 .0 6 3,DM和 NDF中潜在可消化组分比例 (a+b)分别为 92 %和 89%。提高大豆皮替代水平 ,饲粮 DM中慢速消化组分 b直线提高 (P=0 .0 2 3) ,快速消化组分 a趋于下降 (P=0 .14 0 ) ,消化延滞期趋于延长 (P=0 .12 7)。提高大豆皮替代水平 ,对饲粮 DM中其他动态消化参数没有影响 (P=0 .36 0～ 0 .90 3)。随着大豆皮替代玉米与小麦麸水平的提高 ,饲粮 NDF中慢速消化组分的比例 b、潜在可消化组分 (a+b)呈二次曲线规律提高 (P=0 .0 0 1～ 0 .0 0 6 ) ,快速消化组分 a的比例趋于线性提高 (P=0 .0 82 ) ,而慢速消化组分的消化速度 c不受大豆皮替代水平的影响 (P=0 .6 88)。从本试验得出结论 :以大豆皮替代奶牛饲粮中 0 ,2 5% ,50 % ,75%和
An in situ digestion trial was conducted to determine effect of replacing corn and wheat bran with soyhulls (SH) in dairy cow diets on digestion characteristics of dietary dry matter and fiber. Five concentrate mixtures with 0, 25%, 50%, 75% and 100% SH replacements for corn and wheat bran were mixed with forages (50∶50,DM) and were used as treatment diets. The digestion rates of SH DM and NDF were 0.072·h -1 and 0.063·h -1 , and the percentages of potentially digestible DM and NDF for SH were 92% and 89%, respectively. As SH replacements increased, the percentage of slowly digestible DM fraction linearly increased ( P =0.023), the percentage of the fast digestible DM fraction tended to decrease ( P =0.140), digestion lag time tended to be prolonged ( P =0.127), whereas other digestion kinetic parameters were unaffected ( P =0.360～0.903). Increasing SH replacements resulted in a quadratic ( P =0.001～0.006) increase in slowly digestible NDF fraction and percentages of potentially digestible NDF. With increasing SH replacements, fast digestible NDF fractions tended to increase (linear, P =0.082), whereas the digestion rate of dietary NDF was unaffected ( P =0.688). It was concluded that when SH replaced for corn and wheat bran at a rate ranged from 25% to 100% in dairy cow diets, there was no difference in potential digestion fractions and digestion rate of dietary DM, whereas there was a positive effect on fiber digestion.
出处
《中国农业大学学报》
CAS
CSCD
北大核心
2000年第5期81-87,共7页
Journal of China Agricultural University
