暖季补饲矿物元素复合舔砖对放牧牦牛生长性能及产奶量的影响

Effect of supplement of mineral block on growth performance and milk yield of grazing yak in warm season

为了研究暖季补饲矿物元素复合舔砖对放牧牦牛生长性能及产奶量的影响,试验选取健康牦牛140头,按年龄、性别组成相同的原则随机分为对照组和补饲组,每组70头。补饲组在归牧后可自由舔食矿物元素复合舔砖,对照组不补饲,试验期为60 d,测定牧草中矿物元素含量、牦牛生长性能、泌乳母牦牛产奶量。结果表明：与对照组相比,补饲组犊牦牛和青年牦牛总增重和日增重极显著提高（P〈0. 01）;青年牦牛和成年牦牛日增重显著高于犊牛（P〈0. 05）。与对照组相比,补饲组泌乳牦牛产奶量无显著变化（P〉0. 05）,7,8岁泌乳牦牛的产奶量显著高于5岁以下泌乳牦牛（P〈0. 05）。说明在牧草生长旺盛的暖季给牦牛适当补饲矿物元素复合舔砖能提高牧草的利用率和日增重,而犊牦牛和青年牦牛的补饲效果优于成年牦牛。

The aim of the present study was to investigate the effect of the supplemental mineral block on growth performance and milk yield of grazing yak in warm season. The 140 yaks were randomly divided into control group and supplementary feeding group according to the same age principle and sex,with 70 yaks in each group. After returning to grazing,the supplemental feeding group could freely lick the mineral block,while the control group did not receive supplementary feeding,and the experimental period was 60 days. The contents of mineral elements in herbage,growth performance of all yaks and milk yield of lactating female yaks were determined. The results showed that compared with the control group,the total weight gain and average daily gain of the supplemental feeding group were significantly increased（P〈0. 01）.The average daily gain（ADG） of young yaks and adult yaks were significantly higher than those of calves（P〈0. 05）. Compared with the control group,supplementation had no significant effect on milk yield of lactating yaks（P〉0. 05）. The milk yield of lactating yaks at 7 and 8 years old was significantly higher than that of lactating yaks under 5 years old（P〈0. 05）. In conclusion,the utilization rate of forage and the daily gain of yak could be improved by feeding the yak with mineral block in the warm growing season. The effect on calf yak and young yak was better than that on adult yak.