蛋氨酸铜对西门塔尔牛发情周期生殖激素分泌的影响

Effects of Copper Methionine on Serum Reproductive Hormone Level during Estrous Cycle in Simmental Heifers

选用16头18月龄，体况良好，体重380±26kg的西门塔尔牛育成母牛，采用完全随机区组设计分为4纽，以蛋氨酸铜为铜源，研究日粮加铜（O、8、16和24mg／kg）对发情周期生殖激素分泌规律的影响。结果表明：8mg／kg组和16mg／kg组显著提高了发情周期LH、FSH、P4和E2水平（P〈0．05）；24mg／kg组有所提高，但不显著（P〉0．05）。说明添加蛋氨酸铜8～16mg／kg对发情周期生殖激素分泌有显著促进作用。考虑基础日粮的含铜量，建议日粮铜水平为：13．87～21．87mg／kg。

Sixteen Simmental heifers （average BW 380kg, aged 1.5） consuming a corn straw diet were chosen and allocated into four treatments and supplemented copper with four levels （0, 8, 16 and 24 mg/ kg of DM） by copper methionine to evaluate the effects of copper on reproductive hormone excretion during the oestrous cycle. The results showed that serum estradiol, luteinizing-hormone, follicle-stimulating hormone and progesterone concentrations were increased significantly （ P 〈 0.05 ） by supplemental copper methionine at 8-16 mg/kg of DM than control group. Serum estradiol, estriol, luteinizing-hormone, folllcle-stimulatlng hormone and progesterone concentrations were increased by supplemental copper of different copper sources at 24 mg/kg of DM, but no significant difference with control （ P 〉 0.05 ）. This indicated that copper sources had positive effects on reproductive hormone during estrus cycle by supplemental copper at 8-16 mg/kg of DM. Considering the copper content of basal diet, the optimum copper level of diet is 13.87-21.87 mg/kg dry matter.