Vol. 11, Issue 12 (2022)

Administration of GnRH and PGF2a to postpartum anoestrus cows induces precise synchronization of estrus by controlling ovarian follicular and luteal functions. A total of 35 cows having body condition score >2.5 and healthy reproductive organs were selected and divided into two groups. Group I and II cows administered with Ovsynch and double PG protocols to assess the estrus induction, intensity of estrus, time required for onset of estrus and duration of estrus. The mean diameter of follicle 48 h after prostaglandin was 9.91±0.32 and 8.80±0.30 mm in Group I and II, respectively with a significant (p<0.05) difference. The mean time (h) required for the onset of induced estrus and duration of induced estrus were 54.038 ± 1.05; 22.93 ± 0.84, respectively in Group I and 52.15 ± 1.12; 21.15 ± 1.05, respectively in Group II. The conception rate was 93.3 and 84.6% in Group I and II, respectively with overall success rate of 80.0%. The difference in the time required for the onset of estrus (hrs), duration of estrus (hrs), estrus response (%) and conception at first AI (%) were not significant (P>0.05) between two groups.