褪黑素基础上补喂来曲唑和N-甲基-D-天冬氨酸对母羊血浆繁殖激素水平的影响

Effects of Supplement with Letrozole and N-methyl-D-aspartate on Plasma Reproductive Hormone Levels of Ewes on the Basis of Melatonin Supplementation

试验旨在研究反季节给繁殖母羊补喂褪黑素(melatonin,MLT)及在MLT基础上补喂来曲唑(letrozole,LE)和N-甲基-D-天冬氨酸(N-methyl-D-aspartate,NMDA)对母羊血浆繁殖相关激素水平的影响,为调控母羊发情药物的开发及应用提供新思路。试验选取40只(3.0±0.5)岁经产萨福克母羊(平均体重为76.23kg±12.25kg)随机分为4组,每组10只,分别为对照组和试验Ⅰ、Ⅱ、Ⅲ组,分别饲喂基础日粮、基础日粮+MLT 10mg/(只·d)、基础日粮+MLT 10mg/(只·d)+LE 7mg/(只·d)、基础日粮+MLT 10mg/(只·d)+LE 7mg/(只·d)+NMDA 300mg/(只·d)。结果显示,与对照组相比,试验Ⅰ组母羊血浆中促卵泡素(FSH)、雌二醇(E2)、雌三醇(E3)及双氢睾酮(DHT)水平均极显著升高(P<0.01),睾酮(T)水平显著降低(P<0.05);试验Ⅱ组,母羊血浆MLT和LH水平均极显著升高(P<0.01),FSH水平显著升高(P<0.05);试验Ⅲ组,母羊血浆中MLT和促性腺激素释放激素(GnRH)水平均显著升高(P<0.05)。与试验Ⅰ组相比,试验Ⅱ组母羊血浆中MLT显著升高(P<0.05),LH和T水平均极显著升高(P<0.01)。试验Ⅲ组与试验Ⅰ、Ⅱ组相比,FSH水平极显著降低(P<0.01)。综上所述,MLT和LE对母羊繁殖相关激素的释放有促进作用,且两者结合使用可达到调控母羊繁殖相关激素水平的效果;MLT、LE和NMDA组合应用对母羊繁殖激素调控效果不佳。

This experiment was conducted to study the effects of feeding melatonin(MLT)on the breeding ewes in the off-season and feeding letrozole(LE)and N-methyl-D-aspartate(NMDA)on the basis of MLT,and to provide reference for the development and utilization of regulating ewes estrus drugs.Forty health multiparous Suffolk ewes with the age of(3.0±0.5)years old and the average weight of 76.23 kg±12.25 kg were randomly divided into 4 groups,control group and test groupsⅠ,ⅡandⅢ,10 in each group.Control group:Basal diet;Test groupⅠ:Basal diet+MLT 10 mg/d;Test groupⅡ:Basal diet+MLT 10 mg/d+LE 7 mg/d;Test groupⅢ:Basal diet+MLT 10 mg/d+LE 7 mg/d+NMDA 300 mg/d.The results showed that,compared with the control group,the levels of FSH,E2,E3 and DHT in ewes plasma extremely significantly increased(P<0.01),and the level of T significantly decreased(P<0.05)in test group Ⅰ;Plasma MLT and LH levels were extremely significantly increased(P<0.01)and the FSH level was significantly increased(P<0.05)in test groupⅡ;In test groupⅢ,the levels of MLT and GnRH in the plasma of the ewe were significantly increased(P<0.05).Compared with test groupⅠ,the MLT in the plasma of test group Ⅱ was significantly increased(P<0.05),and the LH and T levels were extremely significantly increased(P<0.01).Compared with test groupsⅠandⅡ,the FSH level was extremely significantly lower in test group Ⅲ(P<0.01).In summary,MLT and LE had a promoting effect on the release of reproductive-related hormones in ewes,and the combination of the two could achieve the effect of regulating the hormone levels related to reproductive growth of ewes;The combined application of MLT,LE and NMDA had a poor effect on the regulation of reproductive hormones in ewes.