Assessment of Superovulatory Response Using Hormonal Profile in Buffalo (Bubalus bubalis)

This study was designed to ascertain the relationship between serum hormonal profiles and superovulatory response in buffalo (Number of corpora lutea and recovered embryos). A total of 22 buffaloes were used in the present study. Animals were randomly allocated to two groups, Group 1 (10 buffaloes) was injected with normal saline (Control group) group 2 (12 animals) was superovulated by injection of 3000 IU PMSG at mid luteal phase of the estrous cycle (Superovulated group).Both treated and control groups were synchronized by injection of prostaglandin F2a (double intramuscular injections, 11 day apart). Blood samples were collected daily from all animals for determination of serum progesterone and estradiol levels by Radio immunoassay (RIA). Superovulatory response was monitored daily by using transrectal ultrasonography. In superovulated group, results were classified according to the number of corpora lutea (CL) into high response group (HRG) • 3CL (4.85±0.33 CL) and low response group (LRG) <3CL (1.8±0.14 CL). There was significant (P<0.05) difference between both superovulated groups in the superovulatory response. Progesterone concentrations on the day of superovulatory treatment were significantly (P<0.05) high in HRG (2.3 ±13 ng/ml) than control (1.2±0.12 ng/ml) and LRG (1.28±0.08 ng/ml). In both groups (HRG and LRG), progesterone levels on the day of PMSG injection and on the day of flushing were positively correlated with the superovulatory response. Progesterone concentration on the flushing day in HRG was nearly double and 4 times than the corresponding values in LRG and control one, respectively. Serum estradiol profile did not differ among the control and experimental groups at the start of treatment. Moreover, it was not correlated with the subsequent superovulatory response. There was an increase of estradiol at 48h post PG treatment in HRG followed by decrease. The marked increase of estradiol in LRG continued till the last sample. There was a tight negative correlation between estradiol and recovered embryo in flushing day in LRG. It was concluded that higher progesterone concentration on the day of superovulatory treatment resulted in an increase in ovulation rate and embryo recovery. More over the higher estradiol level in superovulated buffalo resulted low embryo recovery rate.