犊牛早期断奶对青海湖地区母牦牛牧食行为的影响

Effect of early weaning of calves on the grazing behavior of female yaks in the Qinghai Lake Area

为研究犊牛早期断奶对青海湖地区自由放牧条件下牦牛牧食行为的影响。试验于2015年8月22日至11月15日开展,选取26头带犊牦牛作为试验对象,对其中13头牦牛的犊牛实施早期断奶处理作为断奶组,另外13头带犊牦牛作为对照组。断奶组和对照组各随机选取3头牦牛佩戴畜用GPS3300装置,每10min记录一次家畜所在位置和环境温度。试验分为断奶早期(断奶后15d)、断奶中期(断奶后第16天到第38天)、断奶后期(断奶后第59天到第82天)。断奶早期又分为阶段Ⅰ(断奶后第1天到第6天)、阶段Ⅱ(断奶后第7天到第15天)。结果表明:1)断奶早期阶段Ⅰ断奶组的平均日游走距离极显著高于对照组(P<0.01),断奶早期阶段Ⅱ、断奶中期和断奶后期两组的平均日游走距离差异不显著。断奶组在不同时期的平均日游走距离表现为,断奶早期阶段Ⅰ显著高于断奶早期阶段Ⅱ和断奶中期(P<0.05),断奶早期阶段Ⅱ和断奶中期显著高于断奶后期(P<0.05)。对照组则表现为断奶早期阶段Ⅰ、断奶早期阶段Ⅱ和断奶中期显著高于断奶后期(P<0.05)。断奶当天断奶组牦牛的游走距离显著高于对照组。在不同断奶时期断奶组和对照组的昼夜采食规律有所不同。2)断奶早期阶段Ⅰ、断奶早期阶段Ⅱ及断奶中期断奶组和对照组的采食空间分布格局相似,但是断奶中期的采食空间分布格局明显广于断奶早期。断奶后期断奶组和对照组的采食分布格局出现了分化,对照组的采食活动范围明显广于断奶组。研究结果表明,早期断奶会短时间内让母牦牛的牧食行为产生一定的应激反应,但其又可以很快适应失犊的情况。在环境比较恶劣、牧草质量较差的情况下,带犊牦牛和不带犊牦牛种内竞争比较激烈,适合分群放牧。

The aim of this research was to study the effect of early calf weaning on the grazing behavior of female yaks.Twenty-six yak dams with calves were used in this experiment.Thirteen yak dams weaned their calves early,and the other 13 did not（control）.Three randomly selected yak dams from each group were tagged with a GPS3300 from August 22 to November 15,2015.The experiment included three periods：weaning inchoate（1st to 15 th day after weaning）,weaning metaphase（16th to 38 th day after weaning）,and weaning anaphase（59th to 82 nd day after weaning）.The weaning inchoate period was divided into phase I（1st to6 th day after weaning）and phaseⅡ（7th to 15 th day after weaning）.The results showed that：1）the daily moving distance of the early weaning group was higher than that of the control group in phaseⅠof the weaning inchoate period（P〈0.01）,but there was no significant difference during the other three phases（P〉0.05）.The daily moving distance of the early weaning and control groups differed among the four phases.The early weaning group＇s daily moving distance was significantly higher than that of the control group on the weaning day.The early weaning and control group showed different daily grazing patterns in the different weaning phases.2）The grazing space distribution pattern was not significantly different between the early weaning and control group in weaning inchoate phase Ⅰ,weaning inchoate phase Ⅱ,and weaning metaphase.The early weaning and control groups＇ grazing ranges were larger in weaning metaphase than in the weaning inchoate phases.The grazing space distribution pattern differed between the two groups in weaning anaphase.These results indicate that early weaning can affect the grazing behavior of yaks in the short term,but the dams soon adapt to the absence of their calves.The yak dams with calves and those without calves should graze separately in periods of forage shortage.