模拟瘤胃对肉牛日粮中适宜蛋白质含量的研究  

Optimum Protein Content Identification for Beef Cattle Ration in Vitro Simulating Rumen Fermentation System

作　　者：伍佰鑫 张翠永[1] 李晟[1] 罗阳 浣成[1] 樊志坚[1] 

机构地区：[1]湖南省畜牧兽医研究所,湖南长沙410131

出　　处：《中国牛业科学》2017年第5期21-24,共4页China Cattle Science

摘　　要：为了确定肉牛适宜的日粮蛋白质需要,节省精饲料中价格较贵的蛋白质饲料,将肉牛日粮按粗蛋白(CP)含量分为4个处理(静态10%CP、静态12%CP、静态14%CP、每48h在10%CP14%CP之间振荡)、每个处理有8个重复。从2头接有瘤胃瘘管的安格斯肉牛收集瘤胃液,转移到实验室双流量连续培养系统的发酵罐(模拟瘤胃)中。每个发酵罐每天投入72g(DM)的日粮,注入氮气(N_2)以维持厌氧环境,添加人工唾液助消化。结果显示,与第2组(12%CP)相比,瘤胃对干物质(DM)、有机物(OM)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的表观消化率,既不受日粮CP增加也不受日粮CP振荡的影响(P>0.05)。随着日粮CP水平的增加,瘤胃内的pH值呈现极显著的(P<0.01)线性正效应。总的挥发性脂肪酸(VFA)浓度和单个VFA摩尔比例(醋酸、丙酸、丁酸、戊酸、异丁酸和异戊酸),不受日粮CP水平或日粮CP振荡的影响(P>0.05)。各处理组之间的总氮(N)、非氨氮(NAN)和瘤胃非降解蛋白(RUP)的流动以及CP可消化性都无差异。因此,12%CP是肉牛适宜的日粮蛋白质需要,超过这一水平(12%CP),日粮中增加再多的CP含量也没有进一步的好处,即会浪费掉。collected from two fistulated Aberdeen Angus steers, then transported to the fermentation jars using a Du- al-Flow Continuous Culture System in the laboratory. 72 g（DM）diet was daily put into each jar accompa- ny with N2 entering to maitain anaerobic environment and artificial saliva added to help digestion. The re- sult showed that apparent ruminal digestibilities of DM, OM, NDF, and ADF were not affected （P〉 0.05） with the increasing dietary CP or oscillating dietary CP compared with 12% static CP. There was a significant positive linear effect （P〈0.01） on ruminal pH with increasing dietary CP levels, but the total VFA concentration and individual VFA molar proportions （acetate, propionate, butyrate, valerate, iso-- butyrate and iso--valerate） were not affected （P〉0.05） by dietary CP levels or oscillating dietary CP. In addition, there were no significant difference in total N, NAN, and RUP, and CP digestibility among dif- ferent treatments. Hence, 12% CP was the suitable dietary crude protein （CP） content required by beel cattle, while there were no further benefits of feeding greater dietary CP beyond that level.

关 键 词：瘤胃液 CP日粮 连续培养系统 发酵罐 塑料桶 氮利用 

分 类 号：S823.2[农业科学—畜牧学]