Effect of double dose PGF2α on conception rate in repeat breeding dairy animals under field conditions

Repeat breeding is considered as one among the major reproductive disorder among dairy animals that hinders productivity. Incidence of repeat breeder cows in Haveri district is around 25 per cent. The present study aimed to determine the effect of double dose Prostaglandin F2α (PGF2α) at 11 days interval and GnRH injection at the time of artificial insemination (AI) on the conception rate of repeat breeding cows. Twenty repeat breeding HF crossbred cows selected randomly from field and divided into two groups. Group-I (n=10) animals inseminated during normal estrus cycle without any hormonal therapy and kept as control. Group-II (n=10) treated with two doses of 20 μg of PGF2α injection at 11d interval and at the time of artificial insemination treated with 0.02mg GnRH injection. Pregnancy diagnosis was performed per rectally at 45^th to 60^th day post insemination. The conception rate was significantly (p<0.05) higher in Group II cows (70 percent) when compared with conception rate of Group I cows (30 percent).90 percent of Group II cows have shown estrus within 48hrs. But only 60 per cent of untreated cows (Group I) showed estrus with in 48hrs. In conclusion double dose PGF2α with GnRH injection may serve as an excellent treatment for improvement of conception rate in repeat breeding cows under field conditions.