Progestagens and Equine Chorionic Gonadotropin Therapy for Synchronization of Ovarian and Estrous Activity in Goats Primed with Prostaglandins, During the Breeding Season

Abstract

Two separate studies were conducted aiming to determine reproductive performance (Study 1) and ovarian activity (Study 2) in goats treated with progestagen vaginal devices and equine chorionic gonadotropin (eCG). In study 1, estrus induction rate (EIR) and gestation percent (G%) were determined in multiparous (M) and primiparous (P) goats. In study 2, ovarian activity was determined in terms of follicle count (FC) and ovulation rate (OR) in puberal goats. In study 1, 28 P and 44 M goats were treated with progesterone vaginal devices (Conipred-CO) for 12 days and eCG doses of 0 (n = 11 P and 10 M), 200 (n = 11 P and 16 M) or 400 (n = 10 P and 14 M) IU, were administered upon device withdrawal. In study 1, EIR ranged from 45 to 90% and from 63 to 80% for the P and M goats, respectively, whereas G% ranged from 64 to 91% and from 78 to 80% for the P and M goats, respectively. The eCG dose increased significantly (P<0.05) EIR and G% in the P goats. In study 2, puberal goats were treated with Chronogest sponges during 12 days and doses of 0, 100, 200 or 400 IU of eCG (n = 5). The eCG dose did not affect FC, mean values found were 13, 12, 11 and 11 follicles, respectively, for each dose; whereas, OR was greater (P<0.05) in the goats treated with the 400 IU dose (2.87 ovulations), regarding the other doses (1.9 ovulations). In study 1, dose of eCG allowed improvements on EIR and G% in P goats, but not in the M goats; whereas, in study 2, eCG increased OR, in the highest dose group.