围产期奶牛血清代谢物和相关激素水平的变化规律研究

Study on Changes of Serum Metabolites and Related Hormones in Dairy Cows during Transition Period

试验旨在揭示围产期奶牛血清代谢物和相关激素水平的动态变化规律,选取临床健康经产奶牛 20 头,分别于产前 14、7 d 及产后 0、7、14 d 采血并分离血清,检测血清葡萄糖、甘油三酯、非酯化脂肪酸、β-羟丁酸等代谢物浓度和胰岛素、生长激素、脂联素和瘦素等激素水平,并根据相应公式计算胰岛素敏感指数。结果表明:奶牛分娩当天的血糖浓度较高,而后逐步恢复至产前水平;奶牛分娩后甘油三酯浓度下降,非酯化脂肪酸和β-羟丁酸浓度升高;胰岛素浓度在产前 14 d 至产后 7 d 各时间点无显著变化;产前 7 d 时的生长激素浓度高于其他时间点(P<0.01);脂联素浓度在整个试验期无显著变化;瘦素水平在产前 7 d 和产后 0 d升高(P<0.01),但产后 7 d 时下降(P<0.01);胰岛素敏感性指数在分娩当天显著降低,随后逐步恢复。结果表明,奶牛产后体脂动员明显,可能与生长激素、瘦素等激素的调控有关。

In order to reveal the changes of serum metabolites and related hormone of transition dairy cows, a total of 20 clinically healthy, multiparous Holstein cows were selected in the experiment. Blood samples were collected on days -14,-7, 0, 7 and 14 relative to parturition and serum metabolites including glucose, triglyceride, non-esteri fied fatty acids and β-hydroxybutyric acid, and serum hormones including insulin, growth hormone, adiponectin and leptin, were measured. Revised quantitative insulin sensitivity check index (RQUICK) was calculated according to the corresponding formula. Results showed that blood glucose concentration was the highest on the day of calving and then decreased gradually. The decrease of triglycerides concentration and the increases of serum non-esteri fied fatty acids and hydroxybutyric acid concentrations were found during postpartum period. There was no signi ficant change in insulin concentration from d -14 to d 7. Growth hormone was significantly higher on d -7 than that on other time. There was no significant difference in adiponectin concentration during the experimental period. Leptin level was signi ficantly increased on d -7 and d 0, but decreased on d 7. The RQUICK decreased signi ficantly on the day of calving and gradually recovered. The results showed that body fat mobilization was obvious during postpartum period, which may be related to the regulation of growth hormone, leptin and other hormones.