Abstract
The aim of this study was to determine a possible difference in sexual behavior of Dorper rams of either high or low social hierarchy in northern Mexico (26°N). The male′s social status was quantified through a competitive behavioral test in 36 males; the aggressive interactions and their consequences were registered to calculate the success index (SI), where low hierarchy (LH) rams had a SI of 0 to 0.33, and high hierarchy (HH) had a SI of 0.67 to 1.Then, 4-LH-rams (BW:76.5±4.25 and BCS:3.62±0.21) and 4-HH-rams (BW:76.5±2.25 and BW:3.62±0.09), were selected. Thereafter, each male was subjected to a sexual behavior test by exposing each male to one estrus female during 15 min. The appetitive (ASB, anogenital sniffing, approaching, kicking, vocalizations) and consummatory (CSB: unsheathing, mount attempt, full mount, mount with unsheathing and mount with ejaculation) sexual behaviors were registered. The ASB and CSB frequencies between groups were compared with a χ2 test (SYSTAT 12). The HHG showed a higher frequency for both ASB and CSB than the LHG (4225 and 369 vs 3414 and 250, respectively; P < 0.05). In conclusion, high hierarchy Dorper rams displayed more appetitive and consummatory sexual behaviors than low hierarchy ram, without differences regarding body weight and body condition score between experimental groups. Such information non-dependent upon BW or BCS, should be important to further define a possible male-social hierarchy effect to stimulate sexual behavior in anestrous females.
PSX-7 Induction of sexual behavior of Dorper rams treated with GnRH in northern Mexico
