Authors : Ruben Dario Martinez Rojero, Lorenzo Reyna-Santamaria, Alejandro C. Michel-Aceves, Angel A. Mastache-Lagunas, Javier Hernandez-Ignacio and Susana Rojas-Maya
Abstract: In order to evaluate the effect of the site of cooled semen deposition (intrauterine or cervical) on subsequent fertility in Pelibuey ewes, a study was carried out during the breeding season in the dry tropic region from the Southern of Mexico, at 18°15´N and 99°38´W. A total of 40 cycling Pelibuey ewes from 2-4 years of age were used with corporal condition from 2-3, on a scale of 0-5. To synchronize estrus, intravaginal sponges were applied to the females, containing 20 mg of Flourogestone Acetate (FGA) for 11 days, plus 200 IU of equine Corionic Gonadotropine (eCG) administered intramuscularly when, the sponges were removed. Once removed, estrous was detected every 12 h with males fitted with an apron. Of the 40 ewes considered initially, five expelled the sponge and three others did no present estrus, thus 32 were used. Of those that presented estrus, 16 received cervical insemination using cooled semen 12 later and 16 others too were inseminated 12 h later with cooled semen deposited into the uterus by laparoscopy. The semen was collected by artificial vagina from a Dorper ram 12 h before the start of inseminations with an artificial vagina and an evaluation was made of its volume (mL), mass motility (percentage) and spermatic concentration (millions of cells mL-1). For the preparation of the diluents, the following were used: Triladyl (20%), distilled water (60%) and egg yolk (20%). The diluted semen was manually placed into straws with a capacity of 0.25 mL, at 30°C, which were sealed with powdered polyvinyl alcohol. The sealed straws were placed in a plastic container with a water at 30°C, which was introduced into a cooler with ice cubes, where, it was maintained at 5°C, until the insemination took place, within the 12-16 h following its collection. The fertility rate of 75% obtained by intrauterine insemination was higher (p<0.05) than that registered for vaginal insemination (50.0%).
Ruben Dario Martinez Rojero, Lorenzo Reyna-Santamaria, Alejandro C. Michel-Aceves, Angel A. Mastache-Lagunas, Javier Hernandez-Ignacio and Susana Rojas-Maya, 2009. Cervical or Intrauterine Artificial Insemination in Pelibuey Ewes, with Chilled Semen. Journal of Animal and Veterinary Advances, 8: 2621-2625.