Se realizaron dos experimentos para evaluar el “efecto macho” y el amamantamiento en el restablecimiento de la actividad ovárica postparto en ovejas Pelibuey. En el experimento 1, se utilizaron 73 ovejas, que se distribuyeron al azar en cuatro tratamientos: T1, amamantamiento continuo sin macho (n=18), crías con madres durante todo el experimento; T2, amamantamiento continuo con macho (n=18), igual que T1 más “efecto macho” (07:00 a 07:30 h y de 16:00 a 16:30 h); T3, amamantamiento controlado con macho (n=18), las crías tuvieron contacto con sus madres en dos periodos (08:00 a 08:30 h y de 18:00 a18:30 h); y, T4, amamantamiento controlado sin macho (n=19). En el experimento 2, se utilizaron 108 ovejas, distribuidas al azar en dos tratamientos: T1, amamantamiento continuo con macho (n=53), crías junto con sus madres durante toda la fase experimental más “efecto macho” (07:00 a 07:30 h y de 16:00 a 16:30 h); y T2, amamantamiento controlado con macho (n=55), igual que T1, solo que las crías tenían contacto con sus madre en dos periodos (08:00 a 08:30 h y de 18:00 a 18:30 h). El estudio se realizó durante noviembre-febrero de 2009-2010 (experimento 1) y en noviembre-enero 2010-2011 (experimento 2). En el experimento 1, se observó que las ovejas de T3 ovularon a los 27.72 ± 0.56 d postparto (p<0.05) diferente de las ovejas de T1, T2 y T4. Las ovejas de T3 ovularon el 100% siendo diferente de las de T4 (p<0.05). En el experimento 2, se observó que las ovejas con T2, presentaron el primer estro a los 34.02 ± 1.28 (p<0.05) diferente de las de T1, pero no al segundo estro (p>0.05) (52.19 ± 1.58 y 48.36 ± 1.17 d; T1 y T2 respectivamente). No se observaron diferencias (p>0.05) en el porcentaje de ovulación con T1 y T2, al primer y segundo celo; tampoco en el porcentaje de gestación total (58.49 y 67.27 %), porcentaje de parición total (54.72 y 63.64 %), prolificidad total (1.79 y 1.74) y fecundidad (0.98 y 1.11). Por lo anterior, se concluye que en las ovejas Pelibuey amamantando, el “efecto macho” induce el restablecimiento ovárico más temprano. _______________ “MALE EFFECT” AND ITS RELATION WITH THE POSTPARTUM ANESTRUS IN PELIBUEY NURSING EWE. ABSTRACT: To evaluate the “male effect” and the suckling on the reestablishment of the ovarian activity postpartum in Pelibuey ewes, two experiments were conducted. In experiment 1, 73 ewes were distributed at random into four treatments: T1, continuous suckling without male (n=18), the lambs remained with their mothers throughout the experiment; T2, continuous suckling with male (n=18) just as T1 plus the “male effect” (07:00 to 07:30 h and 16:00 to 16:30 h); T3, controlled suckling with male (n=18), the lambs had contact with their mothers in two periods (08:00 to 08:30 h and 18:00 to 18:30 h) and, T4, controlled suckling without male (n=19). In experiment 2, 108 ewes were distributed at random in two treatments: T1, continuous suckling with male (n=53), lambs along with their mothers during all the experimental phase plus the “male effect” (07: 00 to 07:30 h and 16:00 to 16:30 h); and T2, controlled suckling with male (n=55), just as in T1, only that the lambs had contact with their mothers in two periods (08: 00 to 08:30 h and 18:00 to 18:30 h). The study was carried out from November 2009 to February 2010 (experiment 1) and from November 2010 to January 2011 (experiment 2). In experiment 1, it was observed that the ewes of T3 ovulated 27,72 ± 0,56 d postpartum different (p<0.05) from the ewes of T1, T2 and T4. All of the ewes of T3 ovulated compared to those of T4 (p<0.05). In experiment 2, it was observed that the ewes of T2 displayed first oestrus 34,02 ± 1.28 different (p<0.05) from the T1 ewes, but not in the second oestrus (p>0.05) (52.19 ± 1.58 and 48.36 ± 1.17 d; T1 and T2 respectively). Differences were not observed (p> 0.05) in the percentage of ovulation with T1 and T2, to first and the second estrus; neither in the percentage of total gestation (58,49 and 67,27%), percentage of total deliveries (54,72 and 63,64%), total prolificacy (1,79 and 1.74) and fecundity (0,98 and 1.11). In conclusion, in Pelibuey nursing ewes the “male effect” induces an early ovarian reestablishment activity.