赖氨酸铜对西门塔尔牛发情周期生殖激素分泌的影响

选用16头18月龄，体况良好，体重380±17 kg的西门塔尔牛育成母牛，采用完全随机区组设计，研究日粮添加赖氨酸铜（0、8、16和24 mgCu/kg DM）对发情周期生殖激素分泌规律的影响。结果表明：8 mg/kg组和16 mg/kg组显著提高了发情周期LH、FSH、P4和E2水平（P<0.05）；24 mg/kg组有提高趋势，但与对照组比差异不显著（P>0.05）。说明添加赖氨酸铜8~16 mgCu/kg DM对发情周期生殖激素分泌有促进作用，以8 mgCu/kg DM较佳。兼顾基础日粮含铜量，建议日粮铜水平为：13.87 mgCu/kg DM。

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

Sixteen Simmental heifers (average BW 380kg, aged 18 monthes) consuming a corn straw diet were chosen and allocated into four treatments and supplemented with four levels (0, 8, 16 and 24 mgCu/kg of DM) of supplemental copper lysine 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 lysine at 8-16 mgCu/kg of DM than control group. Serum estradiol, estriol, luteinizing-hormone, follicle-stimulating hormone and progesterone concentrations were increased by supplemental copper at 24 mgCu/kg of DM, but no significant difference with control (P>0.05). This results suggested that copper lysine had positive effects on reproductive hormone during estrus cycle by supplemental copper at 8 mgCu/kg of DM. Considering the copper content of basal diet, the optimum copper level of diet is 13.87 mgCu/kg DM。