Journal of Krishi Vigyan

Reproductive inefficiency of cattle due to repeat breeding syndrome is an expensive hitch in profitable dairy production and the incidence of repeat breeding is around 20–25 per cent in Uttara Kannada district of Karnataka. Present study was carried out on 30 repeat breeding cows to study the efficacy of a modified prostaglandin (PG) protocol on conception rate and its impact on estrus duration. Repeat breeding cows were selected after following proper criteria like more than three artificial inseminations with regular oestrous cycles without any signs of pregnancy. Cows were randomly assigned to two treatment groups. All selected animals were initially fed a dewormer and mineral mixture. Group I cows (n = 10) did not receive any treatment and served as control however, Group II cows (n = 20) were injected with double dose prostaglandin (20 μg Dinoprostone, Pragma^®) at 11d intervals and treated with GnRH (0.02mg, Receptal^®) at the time of insemination. Further, the pregnancy status was diagnosed at 45 to 60 d after insemination. The Group II animals showed proper heat signs and pregnancy rates (75.0%) were significantly (p<0.05) higher compared to Group I cows (30.0%). Further, 85per cent of cows treated with PG have shown the estrus duration between 24-48h compared to untreated cows (50%). Hence, use of modified PG protocol with GnRH could be appropriate method to improve fertility in repeat breeding cows under field conditions.