不同精料水平对肉牛饲料瘤胃降解的影响

Effects of Different Concentrate Levels on the Ruminal Degradability of Crossbred Beef

采用4头21月龄,体重300kg左右,安装永久性瘤胃瘘管的杂交阉公牛,采用4×4拉丁方试验设计,以干玉米秸为粗料,精料补充料相同,配制精料水平分别为35%、45%、55%、65%的4种饲粮。采用铬标记法测定饲料的瘤胃流通速度,采用尼龙袋法测定饲料的营养物质降解率,研究不同精料水平下肉牛饲料的瘤胃降解特性。结果表明:精料水平对玉米秸、玉米、干玉米酒精糟及精料补充料的营养物质的瘤胃有效降解率及饲料的瘤胃流通速度有显著影响。饲料k值在45%或55%精料水平时最大,之后随精料水平的提高而减小。营养物质的瘤胃有效降解率在45%～55%精料水平下最高。

Four steers fitted with permanent tureen fistulas were used in this experiment. They were fed on diets containing concentrates 35%, 45%, 55%, 65%, respectively. A 4×4 Latin square design was used to study the effects of different concentrate levels on the ruminal degradability by nylon bag tecnoleg. The rumen outflow rates of the feedstuff were measured used Cr-labeled feeds, and the nutrients degradibilities of the feeds were measured used nylon bag. The results showed that there were significant effects of concentrate levels on nutrients degradibilities and rumen outflow rate of corn stalk, corn, corn distiller dried grain and concentrate supplement. Rumen outflow rates of measured feedstuff were highest at 45% or 55% concentrate level. Ruminal nutrients degradibilities of the feeds were highest between 45% and 55% concentrate level.