Resumen de Ultrasonographic evaluation of ovulatory follicle growth of anestrous crossbred Zebu cows post-treatment with norgestomet and eCG
A. de Ondiz Sánchez, Fernando Pedro Perea Ganchou, Robert Cruz-Arambulo, German Portillo, Eleazar Soto-Belloso
In a study at a commercial farm in a dry tropical forest environment in Zulia State, Venezuela, ovarian ultrasonography was used to evaluate follicular growth and estrus induction in anestrous crossbred Zebu cows beyond 120 days postpartum, following hormone treatment. Of 12 cows treated for nine days with a Sinchro-Mate B (norgestomet + estradiol valerate) implant and an injection of 500 IU of eCG the day of implant removal, 10 showed follicular growth and eight of these an ovulatory follicle (mean diameter, 11.7 mm). Ovulation was confirmed by absence of the preovulatory follicle and development of a corpus luteum 7 days post-estrus (mean size, 16.5 mm). Two-thirds of the animals (8/12) showed estrus behavior after treatment and were artificially inseminated, resulting in a 75% conception rate (6/8). The hormonal treatment was effective for inducing normal-fertility estrus and ultrasonography permitted detailed monitoring of ovarian events.
