Abstract #T293

# T293
Out of breeding season sexual biostimulations of Dorper rams improve they sexual behaviour but not the male effect.
O. Angel-García*1, C. A. Meza-Herrera2, L. R. Gaytán Alemán1, J. L. Morales-Cruz1, E. Carrillo Castellanos3, M. G. Calderón-Leyva4, A. S. Alvarado-Espino1, F. G. Veliz Déras1, 1Universidad Autónoma Agraria Antonio Narro, Unidad Laguna, Torreon, Coahuila, Mexico, 2Unidad Regional Universitaria de Zonas Aridas, Universidad Autónoma Chapingo, Bermejillo, Durango, México, 3Instituto Tecnológico de Torreón No.10, Torreón, Coahuila, México, 4Centro de Bachillerato Tecnológico Agropecuario No. 216, Ciudad Juárez, Durango, México.

The aim was to evaluate if the contact of sexually inactive rams with estrogenized females induces the male sexual behavior during the reproductive resting season (May) and if these treated rams are, in turn, able to stimulate the reproductive response of anovulatory nulliparous ewes in the northern Mexico (26°N). Dorper rams (n = 9) were divided into 3 groups (n = 3 each) with homogeneous live weight and body condition score and exposed during 6 d to: 1) 2 untreated ewes during 24 h (CG); 2) 2 estrogenized ewes (2 mg i.m. of estradiol cypionate every 3 d for 9 d) during 12 h daily (G12); 3) 2 estrogenized ewes for 24 h, replaced by other 2 ewes every 24 h (G24). Once rams were exposed to the “female effect,” 60 nulliparous ewes (diagnosed anovulatory by transrectal ultrasonography) were divided into 3 groups (n = 20 each) and were exposed to the previously treated rams. During the first 2 d, both the appetitive sexual behavior (ASB; i.e., anogenital sniffing, body sniffing, vocalization, kicking and flehmen) and the consummatory sexual behavior (CSB; attempt mount and complete mount) were evaluated 1 h daily. Estrus were monitored twice daily for 5 d to detect estrus signs, and ovulation rate was determined by transrectal ultrasonography. The ASB and CSB frequencies were compared using a Fisher’s test; estrus and ovulatory activities were compared using javascript:lil_chi(2)(Systat 12). Groups CG, G12 and G24 showed ASB values of 29, 35 and 35%, respectively (P > 0.05). Values for CSB in the CG were 17% (P > 0.05), observed the highest in G12 and G24 (38 and 44%; P < 0.05). No differences (P > 0.05) were detected regarding the percentage of females showing estrus, with 85, 71 and 93% in the CG, G12 and G24 groups. In the same way, the percentage of ovulations did not differ (P > 0.05) among groups (84, 71 and 86%, for the CG, G12 and G24). This study showed that the sexual biostimulation of Dorper rams with estrogenized females during 12 or 24 h generated a high consummatory sexual behavior. When these rams exposed to the “female effect” were put in contact with anovulatory nulliparous ewes, the presence of the treated males did not promote any difference regarding the observed reproductive outcomes, considering estrus response and ovulatory activity.

Key Words: biostimulation, behavior, ewes