Progesterone profile and reproductive performance of estrous-induced, Alpine goats given hCG fire days after breeding.

The objective of this study was to investigate lhe effect of hCG administration tive days after breed- ing on plasma progesterone concentration (P4) and reproductive performance of estrous-induced Alpine goats. A total of 42 lactating does were treated with intravaginal sponges (MAP, 60 mg) for 9 d plus 200 lU eCG and 22.5 mg d-cloprostenol 24 h before sponge removal. After detection of estrus (day of estrus = day 0) and breeding, females were randomly assigned into two treatments (T1 and T2). In T1 (n=19) and T2 (n=18) lhe animaIs received intramuscular injection of 1 ml of saline solution (control) or 250 lU hCG, respectively, 5 d after breeding. P4 (ng/ml) was recorded from blood sampled on days O, 5, 7, 13, 17, 21, 28 and 45 after breeding. Animals were scanned with lhe aid of transrectal ultra-sound (5 MHz probe) on days 35 and 70 after breeding, for diagnosis of pregnancy. P4 was higher in lhe hCG-treated than the control animaIs only at day 45 (P 0.05). Results of this study suggest that hCG administration 5 d after breeding may alter the luteal function but not reproductive performance in estrous-induced lactating goats