"En los machos cabríos está documentado que los tratamientos fotoperiódicos que incluyen la exposición de 75 días largos (DL) alternados con el fotoperiodo natural correspondiente a días cortos (DC) crecientes, son eficientes para inducir una intensa actividad sexual durante el periodo de reposo sexual natural. Además, cuando estos machos foto-estimulados son puestos en contacto con hembras anovulatorias durante al menos 15 días estimulan su actividad estral y ovulatoria.Sin embargo, no se conoce si los tratamientos de DL menores a 75 días reducen la respuesta sexual de los machos a dicho tratamiento, así como su capacidad para estimular la actividad ovulatoria de las hembras anéstricas durante el efecto macho. Asimismo, no se conoce si un tiempo de contacto macho-hembra menor a 15 días reduce la respuesta ovulatoria. Por ello, en la presente tesis se llevaron a cabo 3 experimentos para aclarar los planteamientos anteriores""In male goats is documented that the photoperiodic treatments that include the exposure to 75 long days (LD) alternating with short days (DC) corresponding to increasing natural photoperiod, are efficient to induce an intense sexual activity during the natural sexual rest. Furthermore, when these males photo-stimulated are contacted with anovulatory females for at least 15 days, stimulate estrus and ovulatory activity. However, it isn´t known whether treatments of less than 75 days DL reduce male sexual response to treatment, as well as its ability to stimulate ovulatory activity of anestrus females during the male effect. Also isn´t known whether time male-female contact less than 15 days reduces the ovulatory response. Therefore, in this thesis were conducted three experiments to clarify the above statements.In the study 1, two experiments were conducted to determine i) the decrease in DL treatments at 45, 30, or 15 days, does not reduce the sexual response of male goats to treatment; ii) determine whether photo-stimulated males 45 or 30 DL induce ovulation in anovulatory goats activity. In both experiments females and males local goats from the Comarca Lagunera, located in the Mexican subtropics (26°N) were used. In experiment 1 was used 25 adult goats. A group of males (n=5) was exposed to the photoperiod natural variations, while 4 groups (n=5/group) were exposed to 16 hours of light per day for 75, 45, 30, or 15 DL artificial. In the 4 groups, photoperiodic treatments ended on January 15th. Plasma concentrations of"