人工授精后不同阶段葡萄糖、孕酮和雌二醇含量对奶牛妊娠预测的研究

Effects of Different Levels of Glucose,Progesterone and Estradiol on the Pregnancy of Dairy Cows after Artificial Insemination

为探究人工授精后不同阶段葡萄糖、孕酮和雌二醇含量对奶牛妊娠的影响,本实验选取63头2~3胎、3~4岁和体况评分(BCS)2.75左右的健康荷斯坦奶牛,人工授精后经发情鉴定及妊娠诊断将奶牛分为妊娠组(n=24)、未妊娠组(n=19)、返情组(n=20)。分别在人工授精后1、5、17、28 d采集尾静脉血10 mL,测定血浆葡萄糖、孕酮(P4)和雌二醇(E2)含量并进行分析。结果显示:人工授精后第5天妊娠和未妊娠组血浆中孕酮和雌二醇极显著高于返情组;人工授精后第17天返情组和妊娠组血浆中P4、E2含量以及P4/E2极显著高于未妊娠组;人工授精后第28天未妊娠组血浆P4含量显著高于返情组,人工授精后第28天血浆葡萄糖含量妊娠组显著高于返情组。综上表明,人工授精后第5天和第17天高浓度血浆P4和E2有利于维持胚胎细胞正常发育和母体和胚胎识别,提高奶牛胚胎存活率;授精后第28天低浓度葡萄糖不利于妊娠,说明血浆中葡萄糖、孕酮和雌二醇对奶牛人工授精后不同阶段早期妊娠具有预测作用。

This study aimed to investigate the effects of glucose,progesterone and estradiol levels on the pregnancy of dairy cows after artificial insemination.A total of 63 healthy Holstein cows with similar parity,age and body condition were selected.The cows were divided into 3 groups in the late stage,the pregnancy group(n=24),the non-pregnant group(n=19),and the return group(n=20).10 mL of tail vein blood was collected at d 1,5,17 and 28 after insemination,and plasma was measured for glucose,progesterone and estradiol.The plasma progesterone and estradiol on d 5 pregnancy group and non-pregnancy group after artificial insemination were significantly higher than those in the returning to estrus group.The progesterone and estradiol in the returning to estrus group and the pregnancy group were significantly higher than those in the non-pregnancy group on d 17 after artificial insemination,on d 17 after artificial insemination,the plasma P4/E2 in returning to estrus group and pregnancy group were significantly higher than that in non-pregnancy group.The plasma progesterone level in the non-pregnancy group was significantly higher than that in the returning to estrus group on d 28 after artificial insemination.On d 28 after artificial insemination the plasma glucose level was significantly higher in pregnancy group than in returning to estrus group.In summary,progesterone and estradiol in high concentration plasma on d 5 and 17 after artificial insemination are beneficial to maintain the normal development of embryonic cells and the recognition of maternal and embryo,and improve the survival rate of dairy cows.Low concentrations of glucose on d 28 after insemination are not conducive to pregnancy.It is indicated that plasma glucose,progesterone and estradiol have predictive effects on early pregnancy at different stages after artificial insemination in dairy cows.