去势对17～21月龄西门塔尔牛激素分泌的影响

Effects of Castration on Hormone Concentration in Serum of Simmental Cattle Aged from 17 to 21 Months

旨在研究去势对17~21月龄西门塔尔牛血清激素及月增量的影响。选取50头健康、16月龄的西门塔尔公牛,依据体质量进行配对试验,分为去势组和未去势组,每组25头,同一阶段饲喂相同饲粮,试验期150d。结果表明,全期平均月增量去势组比未去势组低6.14%,差异不显著;血清睾酮去势组显著低于未去势组;去势组雌二醇质量浓度有高于未去势组的趋势;去势组的生长激素质量浓度极显著低于未去势组;生长抑素质量浓度去势组显著高于未去势组;去势组的皮质醇质量浓度有低于未去势组的趋势。血液中促肾上腺皮质激素、胰高血糖素、胰岛素、前列腺素E2、甲状腺素和三碘甲腺原氨酸的质量浓度在去势组与未去势组间差异均不显著。表明去势致使17~21月龄西门塔尔牛血液中生长激素质量浓度降低,生长抑素质量浓度增加,但对月增量无显著影响。

The objective of this study is to investigate the hormone secretion and body mass gain ofSimmental cattle aged from 17 to 21 months response to castration.Fifty healthy Simmental cattle with 16-month-old were classified into 2 groups,25 cattles were assigned to the castrated or the uncastrated group according to their body mass.The cattles from 2 groups were feed with same diets according to their nutrients requirements during 150 days＇ the experimental.The results showed that the mean body mass gain was lower than 6.14% in castrated group compared with uncastrated group,there were no significant difference during the experiments period.Compared with uncastrated group,the mass concentration of serum testosterone and growth hormone were significantly decreased,and the mass concentration of cortisol tended to decrease in castrated group.On the contrary,the somatostatin mass concentration was significantly increased,and the estradiol mass concentration tended to increase in castrated group compared with uncastrated group.The mass concentration of adrenocorticotropic hormone,glucagon,insulin,prostaglandin,thyroxine and triiodothyronine between castrated and uncastrated group were not significantly different in the blood.The results suggested that the mass concentration of growth hormone decreased,and the mass concentration of somatostatin induced by castration increased in blood.however,the mean body mass gain was not influenced by castration from 17 to 21 months old in simmental cattle.