血清瘦素和胰岛素与犊牛初生重相关性

Correlation of Leptin and Insulin in Venous Serum with Calf Birth Weight

本实验旨在研究分娩奶牛(Bos taurus)、犊牛和脐静脉血瘦素、胰岛素之间的相关性及与犊牛初生重的相关性,为探究瘦素、胰岛素对犊牛初生重的影响机理提供理论数据。实验选取规模化养殖场正常分娩奶牛54头,按犊牛初生重划分为A组(≤40 kg)9头、B组(40~45 kg)25头、C组(≥45 kg)20头共3组,分别采集分娩奶牛、犊牛和脐静脉血,ELISA法检测血清瘦素、胰岛素含量。多组间采用单因素方差分析和双变量Pearson分析瘦素和胰岛素在各部位静脉血中表达的相关性及与犊牛初生重的相关性。结果表明:(1)奶牛静脉血瘦素、胰岛素含量极显著高于犊牛静脉血和脐静脉血(P<0.01),奶牛静脉血瘦素、胰岛素含量与犊牛静脉血和脐静脉血瘦素、胰岛素相关性均不显著(P>0.05);(2)瘦素、胰岛素含量在犊牛静脉血与脐静脉血之间均差异不显著(P>0.05),犊牛静脉血瘦素、胰岛素含量与脐静脉血瘦素、胰岛素均分别呈极显著正相关(P<0.01);(3)奶牛静脉血和脐静脉血中瘦素与胰岛素含量均呈显著正相关(P<0.05),而犊牛静脉血中瘦素与胰岛素相关性不显著(P>0.05);(4)犊牛初生重与奶牛静脉血瘦素、胰岛素含量均不相关(P>0.05),但与犊牛静脉血和脐静脉血瘦素含量显著正相关(P<0.05),与犊牛静脉血和脐静脉血胰岛素含量极显著正相关(P<0.01);(5)奶牛静脉血、犊牛静脉血和脐静脉血瘦素和胰岛素含量在公犊牛与母犊牛间均无显著差异(P>0.05)。可见,奶牛静脉血、犊牛静脉血和脐静脉血均有瘦素、胰岛素表达,且其含量奶牛静脉血显著高于犊牛静脉血和脐静脉血。奶牛静脉血瘦素、胰岛素含量与犊牛初生重相关性不显著,而犊牛静脉血和脐静脉血瘦素、胰岛素含量与犊牛初生重显著正相关性。

This study aimed to explore the correlation between the calf birth weight and leptin or insulin level in venous serum of the puerperal cow, calves or cords. We chose 54 healthy Holstein cows that experienced normal natural birth, divided them into group A（calf birth weight ≤ 40 kg, n = 9）, group B（calf birth weight 40﹣45 kg, n = 25） and group C（calf birth weight ≥ 45 kg, n = 20）, and collected the venous serum samples from the puerperal cow, the calf and the umbilical cord, respectively. The expression levels of serum leptin and insulin were detected by ELISA. Single factor analysis of variance and bivariate Pearson were used to analyze the correlation of the expression levels of leptin and insulin in these three kinds of venous sera, as well as their correlation with the calf birth weight. The results demonstrated that：（1） Leptin and insulin in venous serum of puerperal cows were significantly higher than in calves and cords（P〈0.01）, while leptin and insulin in venous serum of puerperal cows had no significant correlation with that of calves or cords（P〈0.05）（Table 1）.（2） There was no significant difference in the expression level between leptin and insulin in venous serum of calves and that of cords（P〈0.05）, while leptin and insulin in venous serum of calves had highly significant positive correlation with that of cords（P〈0.01）（Table 2）.（3） There was significant positive correlation between leptin and insulin in venous serum from both puerperal cows and cords（P〈0.05）, but there was no significant correlation in calves（P〈0.05）（Table 3）.（4） The calf birth weight had no significant correlation with leptin and insulin in venous serum of puerperal cows（P〈0.05）; however, it had significant positive correlation with leptin in venous serum（P〈0.05） and highly significant positive correlation with insulin in venous serum（P〈0.01） from calves and cords（Table 4）.（5） There was no significant difference in Leptin and insulin levels in venous serum from puerperal cows, calves or cords between male and female calves（P〈0.05）（Table 5）. In conclusion, leptin and insulin expression levels in puerperal cows were significantly higher than those of calves and cords. The calf birth weight had no significant correlation with leptin and insulin in venous serum of puerperal cows, while it had significant positive correlation with leptin and insulin in venous serum from both calves and cords.