内蒙古绒山羊长绒后期褪黑激素埋植时间对其生产性能的影响

为研究内蒙古绒山羊长绒后期褪黑激素埋植时间对绒山羊产绒性能、生长性能和繁殖性能的影响,于2013年4月底抓绒时选用体重相近、产绒量基本一致的3周岁左右的内蒙古绒山羊30只,随机分成3组,分别为对照组、2013年12月和2014年2月2次埋植组(即12月底开始2次埋植组)以及2014年2月单次埋植组(即2月底单次埋植组),埋植褪黑激素剂量为2mg/kg(BW)。埋植开始至试验结束(2014年4月底抓绒)逐月观察山羊绒生长情况,并采集绒样,用于分析埋植对山羊绒生长的影响。称量试验羊的初始和结束体重,并统计产羔数和羔羊初生重。结果表明:1)单次埋植褪黑激素组在4月底抓绒时绝大多数羊颈部存在明显的脱绒损失,而对照组和2次埋植组并未出现脱绒现象;2)埋植褪黑激素对试验结束时羊体重和日增重没有影响(P0.05),对产羔数和羔羊的初生重也无影响(P0.05);3)各组间羊绒长度和细度无差异(P0.05),2次埋植组羊绒产量与对照组没有差异(P0.05),而单次埋植组羊绒产量因提前脱落损失而显著降低(P0.05);4)1—3月份山羊绒生长速率逐渐降低,各组间没有差异(P0.05),且均在4月份停止生长。因此,2月底单次埋植褪黑激素有促使山羊绒提前脱落的作用,12月底开始2次埋植褪黑激素虽没有促使山羊绒提前脱落,但也没有促进山羊绒生长,并未延长山羊绒生长期。

Effect of melatonin implantation time during the cashmere latter-growing period on production performance of Inner Mongolian Cashmere Goat

This study was conducted to investigate the effects of melatonin implantation during the cashmere latter-growing period on cashmere yield,growth and reproduction performance of Inner Mongolian cashmere goats.Thirty 3-year-old female Inner Mongolia cashmere goats with similar weight and cashmere yield in previous year were randomly assigned to one of the three groups(n=10),including the control group and two treatment groups,where in one treatment melatonin(2 mg/kg BW) was implanted twice at the end of December 2013 and February 2014 respectively and the other is only implanted once at the end of February 2014.Cashmere growth was observed and the cashmere fibre samples were collected monthly following implantation until the end of the experiment in April 2014.Initial and final body weight,litter size and birth weight were recorded.Results showed that:The cashmere fibre of goats with melatonin implantation in February 2014 was shedding obviously in the neck at the end of April 2014.However,there were no cashmere fibre shedding observed in the control and melatonin implantation in December 2013 and February 2014;the final body weight,average daily gain,litter size and birth weight were not influenced by melatonin treatments(P>0.05).Administration of melatonin has no influences on cashmere maximum length and cashmere fibre diameter(P>0.05);No difference was observed in cashmere yield between the control and melatonin implantation in both December 2013 and February 2014.However,the cashmere yield of melatonin implantation in February 2014 was lower than that of the other two groups due to the early shedding(P<0.05);the cashmere growth rate was decreased gradually from January to March and cashmere growth was ceased in April in all goats.There was no difference in the cashmere growth rate among the treats(P>0.05).These data indicated that,melatonin implantation in February 2014 resulted in cashmere shedding in advance.Although the melatonin implantation in December 2013 and February 2014 did not result in early shedding,it did not promote cashmere growth or prolong cashmere growth period.