Estradiol benzoate as substitute for GnRH in protocols for synchronizing ovulation in postpartum anestrum cows

Abstract

The effect of substituting estrogen for the 2nd dose GnRH on the synchronization of ovulation was studied. Healthy pluriparous crossbred cows were selected and randomly divided into two groups (A and B) of six cows each. Cows from group A were treated with injection of 10 µg of GnRH on day 0, 500 µg of PGF2α on day 7 and another 10 µg of GnRH 48 h after PGF2α (day 9) and timed artificial insemination (TAI) was done on day 9 and 10. In group B, the second dose of GnRH was replaced with 1mg of estradiol benzoate injection 24 h after PGF2α (day 8). Intensity of estrum was significantly (P