【摘要】 目的研究日粮氮营养在绒山羊体内的分配机理,调控氮营养在绒山羊体内的分配,提高舍饲绒山羊的经济效益,减少放牧,保护草原生态。方法用缩短光照和埋植褪黑激素的方法调控氮营养向绒毛方向分配。结果光照时间和埋植褪黑激素对绒山羊体内相关激素有显著影响,通过相关激素的变化调节绒山羊体内体氮和毛绒氮的分配比例。短光照和埋植褪黑激素使血液中褪黑激素含量升高,毛绒氮分配比例增加而体氮分配比例减少,促进绒毛生长,试验期内绒山羊的产绒量平均增加338.83±72g,提高73.8%。绒毛各项品质指标均达到纺织工业标准的要求。结论绒山羊的绒毛生长可以通过改变光照和埋植褪黑激素进行调控,在非生绒季节诱导产绒,在生产实践中有巨大的推广价值。更多还原

【Abstract】 【Objective】The effects of photoperiod and melatonin on nitrogen partitioning in Inner Mongolia White Cashmere goats in telogen were investigated.【Method】Eighteen castrated mature goats,23-25 kg of liveweight,were divided into three groups randomly,which were treated with different photoperiods,in each of the groups half of the goats were implanted melatonin.Total deposited nitrogen(TN)was tested by general digestive and metabolism method.Body nitrogen deposited(BN)was measured by isotope dilution technique of tritiated water at the beginning and the end of the experiment,fur nitrogen deposited(FN)were calculated by FN= TN-BN.【Result】Results showed that there was a significant difference in BN and FN partitioning.Hormones relative to nitrogen partitioning and body composition also varied with different treatments.As a result,there was a competitive nitrogen partitioning between body and fur regulated by hormones induced by photoperiod and implanted melatonin.Corresponding to increasing concentration of melatonin in goats blood,there was an additive cashmere in SDPP and implanted groups.Average cashmere production was 338.83±72 g in SDPP and implanted groups,increased by 73.86%.The length of the new grown cashmere was 5.95±0.26-6.32±0.22 cm,the diameter of new cashmere was 14.43±0.28-15.03±0.51 μm,which was decreased by 0.1-0.71 μm compared with the previous cashmere.Although cashmere break strength was reduced by 0.94-1.62 cN,it was still in the range of textile standard.Overall,the textile value of new cashmere was up to grade A,except only one group fall in grade B.【Conclusion】This study has provided evidences that melatonin and photoperiod can be used to improve the cashmere production in practice,the technique can be extended in Inner Mongolia and other areas in north China.更多还原