半舍饲条件下淘汰母牦牛育肥及犊牦牛培育技术研究

旨在研发半舍饲条件下淘汰母牦牛育肥及犊牦牛培育技术。选取带犊母牦牛和公犊牛各66头,分别随机分为试验组和对照组。在犊牛培育期间（2017年12月4日—2018年3月5日）,对试验组母牦牛进行补饲,试验组犊牦牛断乳前（3月5日断乳）随母牦牛哺乳,并进行补饲;对照组母牦牛不进行补饲,按常规放牧方式饲养,对照组犊牦牛进行断乳并补饲。育肥期间（2018年3月5日至出栏）对试验组母牦牛进行补饲,于6月错峰出栏;对照组母牦牛不进行补饲,于集中出栏时间出售（9月或10月）。在犊牦牛培育期间,观察试验组母牦牛的体重变化情况;每月4日测定2组犊牦牛的体重和体尺指标,并进行统计学分析。计算试验组母牦牛错峰出栏收益。结果表明,在犊牦牛培育阶段,由于试验组犊牦牛随母牦牛哺乳,试验组母牦牛体重平均下降1.17 kg/头;2018年1月4日,试验组犊牦牛的体重极显著（P<0.01）高于对照组,体斜长和胸围显著（P<0.05）高于对照组;2018年2月4日和3月4日,试验组犊牦牛的体重、体高、体斜长、胸围均极显著（P<0.01）高于对照组。试验组母牦牛错峰出栏的效益为1 063.05元。研究结果为提高半舍饲条件下淘汰母牦牛养殖效益以及提升犊牛培育质量提供了技术支撑。

Technique for Culling Female Yaks Fattening and Yak Calves Rearing under Semi-confined Condition

The objective of this study was to develop a set of technique for culling female yaks fattening and yak calves rearing under semi-confined condition. A total of 66 lactational female yaks and 66 male yak calves were selected and randomly divided into experimental group and control group, respectively. During the yak calves rearing period （from December 4, 2017 to March 5, 2018）, the female yaks of the experimental group received supplementary feeding. The yak calves of the experimental group received milk from the female yaks of the experimental group before weaning （on March 5，2018） and simultaneously received supplementary feeding. The female yaks of the control group received no supplementary feeding and were kept in the conventional grazing mode. The yak calves of the control group were weaned on December 4, 2017 and received supplementary feeding. During the fattening period （from March 5, 2018 to slaughter）, the female yaks of the experimental group received supplementary feeding and were slaughtered in June （non-peak time for yak slaughter）; the female yaks of the control group received no supplementary feeding and were slaughtered in September or October （peak time for yak slaughter）. During the yak calves rearing period, the body weight of the female yaks of the experimental group was observed and recorded. The body weight and body size indicators of the two groups of yak calves were measured on the 4th of each month, and statistical analysis was performed. The fattening profit of the female yaks of the experimental group in non-peak time for slaughter was calculated. The results showed that during the yak calves rearing period, the weight of the individual female yak of the experimental group was 1.17 kg reduced due to the lactation for the yak calves of the experimental group. On January 4, 2018, the weight of the yak calves of the experimental group was extremely significantly higher （P<0.01） than that of the control group, and the body length and chest circumference were significantly higher （P<0.05） than of the control group; on February 4 and March 4, 2018, the yak calves of the experimental group had extremely significantly higher （P<0.01） body weight, body height, body length and chest circumference compared to that of the control group. The fattening profit of the female yaks of the experimental group in non-peak time for slaughter was 1 063.05 Yuan. Our results provide technical support for improving the fattening profit of culling female yaks and the rearing quality of yak calves under semi-confined condition.