梯牧草和燕麦草的营养价值及其奶牛瘤胃降解特性

Nutritional value of timothy grass and oat grass and their rumen degradation properties in dairy cows

选择3头安装有瘤胃瘘管的中国荷斯坦奶牛进行头茬、二茬梯牧草和燕麦草体内试验,比较3种饲草的营养成分及其瘤胃降解率和降解特性的差异。结果表明:梯牧草的粗蛋白质(CP)和粗脂肪质量分数显著高于燕麦草的,而可溶性碳水化合物和相对饲喂价值则显著低于燕麦草的,梯牧草头茬和二茬间的营养成分的差异无统计学意义;燕麦草、二茬和头茬梯牧草的瘤胃内干物质有效降解率依次为48.22%、41.76%和36.54%,且三者间的差异有统计学意义;二茬梯牧草和燕麦草的瘤胃内CP有效降解率相近,分别为53.09%和53.20%,且显著高于头茬梯牧草的(36.67%);二茬梯牧草和燕麦草的瘤胃内中性洗涤纤维有效降解率分别为36.61%和35.10%,且两者间的差异无统计学意义,但均显著高于头茬梯牧草的(28.62%)。可见,二茬梯牧草具有作为奶牛常规粗饲料资源的潜力,可用于替代燕麦草。

Three Chinese Holstein cows with permanent ruminal cannulas were selected to evaluate the nutritive value and to investigate the rumen degradation rate and degradation characteristics of the first cut(1st cut)premium timothy hay,second cut(2nd cut)timothy hay and oat hay for dairy cows.The results showed that the mass fractions of the crude protein(CP)and ether extract in 1st cut timothy hay and 2nd cut timothy hay were significantly higher than those in oat hay,while the water soluble carbohydrate and relative feed value were significantly lower than those in oat hay.There was no significant difference in nutritive values content between 1st cut timothy hay and 2nd cut timothy hay.In the rumen,the effective dry matter degradation rates of oat grass,2nd cut timothy hay and 1st cut timothy hay were 48.22%,41.76%and 36.54%respectively,and the differences among them were statistically significant.There was no significant difference in the CP effective degradability between 2nd cut timothy hay(53.09%)and oat hay(53.20%),but both of them were significantly higher than that in 1st cut timothy hay(36.67%).There was no significant difference in the neutral detergent fiber effective degradability between 2nd cut timothy hay(36.61%)and oat hay(35.10%),but both of them were significantly higher than that in 1st cut timothy hay(28.62%).Together,it can be seen that 2nd cut timothy hay has the potential as a conventional roughage resource for dairy cows and can be used to replace oat hay.