The effect of hCG administration on reproductive performance in undernourished lactating hair goats synchronized during non-breeding season

Abstract

This study aimed to assess the effects of short and long synchronization protocols, combined with post-synchronization human chorionic gonadotropin (hCG) administration, on the reproductive performance of lactating hair goats during the non-breeding season, considering their inadequate pasture conditions. A total of 60 goats were randomly divided into four groups (G1, G2, G3, G4). Progesterone (flugeston acetate)-impregnated intravaginal sponges with were used for 5 days in G1 and G2 and 12 days in G3 and G4. All received a 500 IU pregnant mare’s serum gonadotropin (PMSG) injection 48 h before sponge removal and were exposed to bucks 12 h later. Groups G2 and G4 received a 500 IU hCG injection on the eighth day after mating. Groups G1 and G3 did not receive any application after mating. Blood samples were collected on the 8th, 15th, and 22nd days for post-mating progesterone analysis, and pregnancy examinations were performed on the 35th day. The study showed a 90% total oestrus rate (54/60). However, there were no significant differences in conception, pregnancy, and kidding rates among the groups. Serum progesterone concentrations significantly increased on the 15th day in G2 and G4, where hCG was administered. In summary, hCG raised progesterone levels but did not significantly affect the reproductive performance of undernourished, lactating goats in a non-breeding season, suggesting that environmental factors and animal nutrition play a crucial role in synchronization outcomes.