PSX-17 Induction of sexual behavior of Dorper rams treated with hCG in northern Mexico

Abstract

Abstract To assess whether the application of HCG induces sexual behavior of rams of Dorper rams, a study was conducted in northern Mexico (26 º N). Dorper rams (n = 12) were divided into 2 groups (n = 6 each) with homogeneous body weight (78.0 ± 2.5) and body condition score (BCS = 3.3 ± 0.3; 1–5 scale). One group (HCG) received 300 IU of hCG i.m., every 3 d x 1 week, while the other group (CONT) received 0.5 mL of physiological saline solution i.m. every 3 d x 1 week At the end of the treatments, rams were subjected to a sexual behavior test by exposing each male to a female in estrus during 15 min; both the appetitive (ASB, anogenital sniffing, approaching, kicking, vocalizations) and the consummatory (CSB: unsheathing, mount attempt, full mount, mount with unsheathing and mount with ejaculation) sexual behaviors where registered. Data were analyzed with the χ2 test (SYSTAT 12). Both ASB and CSB behaviors favored (P < 0.05) to the HCG rams; ASB 69% vs 30% and CSB 73% vs 27%. Administration of HCG in Dorper rams at 26° North induced a higher sexual behavior; the last should be of interest to enhance the out-of-season reproductive outcomes in the sheep industry.