Authors : Zhanxing He, Meifen Huang, Jicai Zhang, Ankui Wang, Xiandong Jin, Kai Yang, Fengwei Zhang, Bizhi Huang and Kaixing Qu
Abstract: Plasma hormone levels were conducted through radioimmunoassay from grazing Dulong cows. Two surges of E2 profile were found on standing estrous (18.56±7.87 pg mL–1) and on days 240-270 of pregnancy (11.85±3.45 pg mL–1), the lowest on days 5-10 of post-copulation (p<0.05). P4 concentration was found the highest on days 5-10 of post-copulation (9.35±2.84 ng mL–1) (p<0.01) and the lowest on standing heat (0.29±0.13 pg mL–1), significantly lower than that during gestation (p<0.05). A biphasic FSH surges were observed during estrous forepart (2.03±0.54 mIU mL–1) and on days 2-30 of postpartum (2.23±0.61 mIU mL–1). Surge LH concentration reachedon days 5-10 of gestation (10.21±9.04 mIU mL–1). Surge T level was found on days 240-270 of pregnancy, significantly higher than those in other PPSs (p<0.01). The significant positive correlations were found between PPSs and plasma FSH (r = 0.34, p<0.05), P4 (r = 0.31, p<0.05), T (r = 0.48, p<0.01) concentrations, respectively, also between P4 and LH (r = 0.31, p<0.05), T and FSH (r = 0.40, p<0.01) while a negative correlation was between plasma E2 and P4 (r = -0.29, p<0.05). In conclusion, Dulong cows were found with two surges of hormone E2 and FSH and a single surge of hormone P4 and T. There were increasing at levels of FSH, P4 and T, the synergistic relationships between P4 and LH, T and FSH, the antagonistic relationship between E2 and P4, were firstly reported in Dulong cows during PPSs.
Zhanxing He, Meifen Huang, Jicai Zhang, Ankui Wang, Xiandong Jin, Kai Yang, Fengwei Zhang, Bizhi Huang and Kaixing Qu, 2020. Reproductive Hormone Concentrations and Their Correlation of Different Physiological Stages in Dulong Cows (Bos frontalis). Journal of Animal and Veterinary Advances, 19: 159-166.