Association of taurine with ovarian follicular steroids and postpartum anestrus condition in Murrah buffaloes.

Taurine is an abundant intracellular beta-amino acid majorly synthesized in the liver and transported through plasma. In mammals, taurine was reported to be involved in various physiological functions, including the enhancement of testosterone levels, the major estradiol precursor. Therefore, we hypothesize that taurine levels are associated with ovarian follicular steroids as well as with a reproductive problem called postpartum anestrus (PPA) in dairy buffaloes. To understand the taurine levels and its possible role in buffalo ovarian follicles, a correlation was established among taurine, estradiol, and testosterone levels in the ovarian follicular fluid. For this purpose, buffalo ovaries were obtained from the slaughterhouse, and follicular fluid samples were collected from small (<4 mm), medium (4-8 mm) and large (>8 mm) follicles. Taurine and steroid levels in the follicular fluid were analyzed by TLC and ELISA, respectively. Taurine and testosterone levels were significantly (P < 0.05) higher in the follicular fluid of small and medium follicles than large follicles, whereas the estradiol levels were significantly (P < 0.001) higher in the large follicles. Thus, taurine showed a positive correlation (r = 0.75) with testosterone and a negative correlation (r = -0.77) with estradiol in buffalo follicular fluid, indicating its possible role in testosterone function during follicular development. Interestingly, significantly (P < 0.001) lower plasma taurine levels in PPA (n = 50) than normal cyclic (n = 50) buffaloes represented its association with PPA. Therefore, our present study recommends the need for future nutrition studies on taurine supplementation to PPA buffaloes.