养殖与饲料

[目的]为解决西藏高寒牧区牦牛均衡营养供应问题，探索浓缩营养舔砖补饲对产犊牦牛及犊牛健康的影响。[方法]试验选择妊娠后期母牦牛36头，随机分成试验组和对照组，组间年龄结构及胎次组成相同，膘情基本一致。以现场生产饲养方式为对照，试验组补饲浓缩营养舔砖。产犊后记录犊牛初生重，并记录60 d犊牛成活数，计算成活率；于产犊后24 h内采集初乳，进行乳成分分析；采集母牦牛及犊牛血液，测定血清生理生化指标。[结果]繁殖母牦牛补饲浓缩营养舔砖，舔食量为0.22 kg/d，围产期母牦牛有不同程度的掉膘；补饲浓缩营养舔砖可提高犊牛初生重，其中母犊牛初生重较对照组显著提高（P<0.05）；补饲浓缩营养舔砖有提高初乳乳脂率、乳蛋白、非脂固形物、犊牛60 d成活率等指标的趋势,而对产犊母牦牛及犊牛血液血清生理生化各指标均无显著影响（P>0.05）。[结论]西藏高寒牧区围产期繁殖牦牛补饲浓缩营养舔砖可提高犊牛初生重。

[Objectives]The effects of licking block supplementation with concentrated nutrients on the health of calving yaks and their calves were studied to solve the problem of balanced nutrition supply for yaks in the high-altitude pastoral areas of Xizang Autonomous Region. [Methods]36 late-gestation yaks were randomly divided into an experimental group and a control group, with the same age structure and parity composition between groups, and basically the same body condition score. The control group received the standard pasture-based management regimen, while the treatment group was supplemented with licking blocks of concentrated nutrients as a dietary supplement. The birth weight of calves after calving was recorded. The number of survival calves at 60 days was monitored to calculate the survival rate. Samples of colostrum within 24 hours after calving were collected to analyze the composition. Samples of blood from calving yaks and calves were collected to determine the physiological and biochemical indexes of serum.[Results]The periparturient yaks had varying degrees of body weight loss when breeding yaks were supplemented with licking blocks of concentrated nutrients, with a licking capacity of 0.22 kg/d. Supplementation with licking blocks of concentrated nutrients increased the birth weight of calves, with a significant increase in the birth weight of female calves compared to that of the control group(P<0.05). Supplementing licking blocks of concentrated nutrients had a trend of increasing indexes including the content of fat in colostrum, milk protein, non-fat solids, and the survival rate of calves at 60 days while having no significant effects on the physiological and biochemical indexes of serum in calving yaks and their calves(P>0.05).[Conclusions]Supplementing licking blocks of concentrated nutrients for peripartum breeding yaks in the high-altitude pastoral areas of Xizang Autonomous Region significantly increased the birth weight of calves, with a tendency to increase the quality of colostrum and the survival rate of calves during the period of lactation.