非常规粗饲料在奶牛瘤胃中的降解特性

Degradation Characteristics of Unconventional Roughages in Rumen of Dairy Cows

本试验旨在对5种非常规粗饲料(花生秧、青稞草、荞麦秸秆、蛋白桑青贮和小麦青贮)进行营养价值评定,并研究其在奶牛瘤胃中的降解特性。采用尼龙袋评定法评定5种规粗饲料的干物质(DM)、粗蛋白质(CP)、中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)的72 h动态降解率和有效降解率。结果表明:1)蛋白桑青贮的CP含量最高,显著高于其他粗饲料(P<0.05);荞麦秸秆的CP含量最低,显著低于其他粗饲料(P<0.05)。荞麦秸秆的NDF和ADF含量均显著高于其他粗饲料(P<0.05)。2)蛋白桑青贮各个时间点的DM降解率和DM有效降解率显著高于其他粗饲料(P<0.05)。3)蛋白桑青贮各个时间点的CP降解率和CP有效降解率显著高于其他粗饲料(P<0.05);荞麦秸秆各个时间点的CP降解率最低,显著低于其他粗饲料(P<0.05)。4)5种粗饲料的NDF、ADF快速降解部分差异不显著(P>0.05),小麦青贮的NDF和ADF慢速降解部分和有效降解率均显著高于其他粗饲料(P<0.05)。综上所述,蛋白桑青贮的CP瘤胃降解率高,营养价值较高;荞麦秸秆的营养价值相对较差。

The purpose of this experiment was to evaluate the nutritional value of 5 unconventional roughages(peanut seedlings,barnyard grass,buckwheat straw,protein mulberry silage and wheat silage),and to study the degradation characteristics in rumen of dairy cows.The nylon bag evaluation method was used to evaluate the 72-hour dynamic degradation rate and effective degradability of dry matter(DM),crude protein(CP),neutral detergent fiber(NDF)and acid detergent fiber(ADF).The results showed as follows:1)the CP content of protein mulberry silage was the highest,and significantly higher than that of other roughages(P<0.05);the CP content of buckwheat straw was the lowest,and significantly lower than that of other roughages(P<0.05).The NDF and ADF contents of buckwheat straw were significantly higher than those of other roughages(P<0.05).2)The DM degradation rates at each time point and DM effective degradability of protein mulberry silage were significantly higher than those of other roughages(P<0.05).3)The CP degradation rates at each time point and CP effective degradability of protein mulberry silage were significantly higher than those of other roughages(P<0.05);the CP degradation rates at each time point of buckwheat straw were the lowest,and significantly lower than that of other roughages(P<0.05).4)The fraction of immediately degraded of NDF and ADF of 5 roughages had no significant difference(P>0.05),and the fraction of slowly degraded and effective degradability of NDF and ADF of wheat silage were significantly higher than those of other roughages(P<0.05).In summary,the CP protein degradation rate of protein mulberry silage is high,and the nutritional value is high;while the nutritional value of buckwheat straw is relatively poor.