Authors : Zhan-Xing He, Mei-Fen Huang, An-Kui Wang, Ji-Cai Zhang, Gang Zhao, Xi-Ping Yuan, Kai-Xing Qu and Bi-Zhi Huang
Abstract: The present study was aimed to investigate the patterns of plasma hormones including oestradiol-17β (E2), Progesterone (P4), Follicle-Stimulating Hormone (FSH), Luteinizing Hormone (LH) and Testosterone (T) profiles in Mithun bulls (Bos frontalis) kept together with females under a semi-management. Blood plasmas of 16 Mithun bulls at 1, 2, 3, 4 and 8 years were collected by jugular venipuncture, respectively. Plasma E2, P4, FSH, LH and T were measured by Radioimmunoassay (RIA). As plasma T levels were increasing with age and reached a peak at 8 years (11.39±0.26 ng mL-1) (p<0.01) with significant positive correlation between plasma T concentration and bull ages (r = 0.933, p<0.01), body weight (r = 0.726, p<0.01). Plasma P4 concentration was gradually decreasing with age and the peak of P4 concentration was observed at 1 year (0.43±0.14 ng mL-1) while it stayed the lowest level at 8 years (0.13±0.02 ng mL-1) (p<0.05). The plasma P4 concentrations had a significant negative relationship with age (r = -0.519, p<0.05), body weight (r = -0.468, p<0.05) in Mithun bulls. Also the plasma E2, FSH and LH concentrations trended to decrease with age (p>0.05). The plasma FSH concentration had a significant positive correlation with P4 concentration (r = 0.621, p<0.01), similar to a positive correlation between plasma LH and P4 concentrations (r = 0.259, p>0.05). The negative correlation were found between the concentrations of plasma P4 and E2 (r = -0.126, p>0.05) and between T and P4 levels (r = -0.431, p = 0.057), respectively.
Zhan-Xing He, Mei-Fen Huang, An-Kui Wang, Ji-Cai Zhang, Gang Zhao, Xi-Ping Yuan, Kai-Xing Qu and Bi-Zhi Huang, 2014. Patterns of Plasma Hormone Concentrations in Mithun Bulls Under a Semi-Management. Journal of Animal and Veterinary Advances, 13: 732-739.