绒山羊非长绒期埋植褪黑激素对其产绒性能和血浆褪黑激素浓度的影响

为研究内蒙古绒山羊非长绒期埋植褪黑激素对其产绒性能和血浆褪黑激素浓度的影响,采用完全随机试验设计方法,将18只体重基本一致、上一年产绒量较为接近的3周岁内蒙古绒山羊半同胞母羊,随机分为2组,一组为对照组,另一组为试验组,每组9只羊。试验组于抓绒后在羊颈部皮下2次埋植褪黑激素(5月中旬和7月中旬),试验期共5个月。试验开始后逐月观察山羊绒生长情况;当埋植组或对照组开始长绒时,剪取绒毛样品用于生长量和细度测量;每月采集血样分析血浆褪黑激素含量。结果表明:1)埋植组大部分绒山羊6月底羊绒已经长出体表,7月底所用试验羊均已长绒,而对照组8月底大部分羊开始长绒,直至9月底才全部长绒。2)7月底,当对照组还没有长绒时,埋植组羊绒平均长度达34.95mm;9月底,当对照组全部长绒,平均羊绒长度达到22.45mm时,埋植组羊绒平均长度已达57.51 mm,显著高于对照组(P0.05);埋植褪黑激素对羊绒细度无影响(P0.05)。3)对照组从6月起无论白天还是黑夜褪黑激素浓度均逐渐升高,至8月达到最大水平,埋植组在7月达到最高浓度,后缓慢下降至自然水平。在6和7月份,埋植组白天和夜晚血浆褪黑激素含量均显著高于对照组(P0.05),而8和9月份2组间差异不显著(P0.05),但8月份埋植组有高于对照组的趋势。因此,内蒙古绒山羊抓绒后,按2mg/kg(BW)的剂量分2次埋植褪黑激素,可提高血浆中褪黑激素的浓度并诱导山羊绒提前萌发,并且不会影响细度。

Effects of melatonin implantation during cashmere non-growing period on the production performance and plasma melatonin concentration of Inner Mongolian cashmere goats

The study was conducted to investigate the effects of melatonin implantation on cashmere yield,length,fibre diameter and plasma melatonin concentration of Inner Mongolia cashmere goats during the cashmere non-growing period.Eighteen 3-year-old,female,half-sib,Inner Mongolian cashmere goats with similar weight and cashmere yield in the previous year were randomly assigned to two groups (n=9) including a control group and a melatonin implantation group that was implanted with melatonin on May 15th and July 21st,respectively.Cashmere growth was observed,and the cashmere fibre samples and blood samples were collected monthly following implantation until the end of the experiment on September 29th, 2014.The results showed that:1) Melatonin implantation on May 15th initiated cashmere growth ahead of schedule in June and the cashmere growth in all of the melatonin-treated goats was initiated in July.2) The average length of cashmere in melatonin implantation group was 34.95 mm in June.However,the growth of cashmere in control group was not initiated.When the length of cashmere in control group was just up to 22.45 mm,the treatment group reached 57.51 mm,which was significant higher than the former (P<0.05).The administration of melatonin had no influence in cashmere fibre diameters (P>0.05).3) The concentration of melatonin of control group increased to its maximum in August from June and July of the melatonin implantation group,which decreased to normal level in August.The melatonin concentrations of melatonin implantation group both in the daytime and nighttime were significantly higher than those in control group in June and July (P<0.05),and there was no difference in August and September (P>0.05).The data indicated that melatonin implantation after combing could increase plasma melatonin concentration significantly and induce cashmere growth.