褪黑激素调控山羊绒生长的模式及机理初探

发布时间：2018-08-18 17:12

【摘要】：本论文分两部分共四个试验研究探讨了MEL调控山羊绒生长的模式及机理。第一部分,调控模式：选用辽宁绒山羊分别研究了春季埋植(3月和5月2次埋植；3月、5月和7月3次埋植)、冬季埋植(10月和12月2次埋植；10月、12月和2月3次埋植)以及全年埋植(2012年3月-2013年3月)MEL对山羊绒生产的影响；选用内蒙古绒山羊分别研究了非长绒期埋植(4月和6月2次埋植；6月单次埋植)和长绒后期埋植(12月和2月2次埋植)MEL对绒山羊生产的影响。结果表明：(1)目前,辽宁绒山羊大部分已具备常年长绒特性；春季、冬季及全年埋植均能在埋植期内提高常年长绒羊绒毛的生长率,但只有全年埋植组提高了产绒量(P0.05)；除10月和12月2次埋植组外,其他埋植组均出现不同程度的提前脱绒,其中全年埋植组最为严重。(2)内蒙古绒山羊非长绒期埋植MEL可促使山羊绒提前生长,并使诱导的山羊绒生长与自然状态下的山羊绒生长有效衔接,没有出现提前脱绒现象,其中4月和6月2次埋植使产绒量和绒长度分别提高16.2%和17.3%(P0.05)。长绒后期埋植MEL仅提高了3月份绒毛生长速率,并未延长长绒期,对产绒量和绒长度没有影响。此外,MEL埋植对绒山羊的生长和繁殖性能没有影响,对山羊绒的细度也没有影响。第二部分,调控机理：选用辽宁绒山羊研究春季埋植(3月和5月2次埋植；3月、5月和7月3次埋植)MEL对绒山羊血液激素及毛囊密度的影响；选用内蒙古绒山羊研究4月和6月2次埋植MEL对绒山羊生产、血液激素及RORa基因表达的影响。结果表明：(3)春季埋植MEL提高了常年长绒羊血液中MEL浓度,降低了PRL浓度(P0.05),而对IGF-1、T3和T4没有影响。此外,MEL埋植提高了次级毛囊密度(P0.05),并使初级毛囊提前达到稳定数量。(4)4月和6月2次埋植MEL使内蒙古绒山羊绒毛萌发时间提前(P0.05),长绒期延长37天(P0.05),产绒量和绒长度分别提高34.5%和21.3%(P0.05),并降低绒细度4.4%(P0.05)；埋植MEL显著提高了白天和夜间血液中MEL浓度、降低了PRL浓度,并使皮肤中RORa基因的表达量升高(P0.05)。以上结果说明：辽宁绒山羊多具常年长绒特性,MEL埋植对常年长绒羊绒毛生长有促进作用,但对提高山羊绒产量的作用不大,可以通过调整埋植时间避免提前脱绒。内蒙古绒山羊非长绒期4月和6月2次埋植MEL是一种有效的调控模式,长绒后期MEL埋植不能延长山羊绒的生长期,亦说明实现季节长绒羊全年长绒不可行。外源MEL通过提高体内MEL浓度、降低PRL浓度、增加次级毛囊密度,使RORa基因表达量上升,从而延长长绒期促进山羊绒生产。
[Abstract]:In this paper, four experiments were conducted in two parts to study the mode and mechanism of MEL regulating cashmere growth. Part one: Liaoning cashmere goats were planted in spring (twice in March and May, 3 in March, May and July), and in winter (twice in October and December). The effects of MEL implantation on cashmere production in October, December and February were studied in Inner Mongolia Cashmere Goat (April and June, 2 times in April and June respectively), and the effects of MEL implantation on cashmere production in the whole year (March 2012 to March 2013) were studied respectively in Inner Mongolia Cashmere Goat (Nei Mongol Cashmere Goat). Effects of MEL on Cashmere Goat production after single implantation in June and late Placement (in December and February) in Cashmere Goats. The results were as follows: (1) at present, most of Liaoning cashmere goats had the characteristics of perennial long velvet, and planting in spring, winter and whole year could increase the growth rate of perennial cashmere wool in spring, winter and whole year, but only the whole year planting group could increase the yield of cashmere (P0.05). Except in October and December, the other groups had different degrees of early delamination. (2) MEL implantation in non-long cashmere period of Inner Mongolia Cashmere Goat could promote the growth of cashmere in advance. The induced cashmere growth was effectively connected with the natural cashmere growth, and there was no early delamination. The yield and length of cashmere were increased by 16.2% and 17.3% respectively in April and June (P0.05). MEL implantation only increased the growth rate of villus in March, but did not prolong the period of long velvet, and had no effect on the yield and length of wool. In addition, Mel implantation had no effect on the growth and reproduction performance of cashmere goats, nor on the fineness of cashmere. The second part: Liaoning Cashmere Goat was selected to study the effects of MEL on blood hormone and hair follicle density in Cashmere Goat in spring (twice in March and May, 3 times in March, May and July). The effects of MEL implantation in April and June on the production, blood hormone and RORa gene expression of Cashmere Goat were studied in Inner Mongolia Cashmere Goat (Inner Mongolia Cashmere Goat). The results showed that: (3) implantation of MEL in spring increased the concentration of MEL in blood and decreased the concentration of PRL (P0.05), but had no effect on IGF-1T _ 3 and T _ 4. In addition, the density of secondary hair follicles was increased (P0.05), and the number of primary hair follicles reached stable in advance. (4) MEL implantation twice in April and June made the time of villus germination advance (P0.05), the long cashmere period prolonged 37 days (P0.05), cashmere yield and length of cashmere were prolonged by 37 days (P0.05). The velvet fineness was increased by 34.5% and 21.3% (P0.05), and the velvet fineness was decreased by 4.4% (P0.05). Implantation of MEL significantly increased the concentration of MEL in blood during day and night, decreased the concentration of PRL, and increased the expression of RORa gene in skin (P0.05). The results showed that: most of Liaoning cashmere goats have the characteristics of perennial long velvet. Mel implantation can promote the growth of perennial cashmere wool, but it has little effect on the increase of cashmere yield, so it can be avoided by adjusting the planting time. MEL implantation in non-long cashmere period of Inner Mongolia cashmere goat in April and June is an effective control mode. MEL implantation in late cashmere period can not prolong the growth period of cashmere, which also indicates that it is not feasible to realize long cashmere sheep in season. Exogenous MEL can increase the concentration of MEL, decrease the concentration of PRL, increase the density of secondary hair follicles, and increase the expression of RORa gene, thus prolonging the long cashmere period to promote cashmere production.
【学位授予单位】：中国农业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S827

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