Brazilian Journal of Veterinary Research and Animal Science
versão On-line ISSN 1678-4456
VISINTIN, José Antonio et al. Superovulation of Nelore heifers with different FSH/LH doses and embryo freezing by one-step method with ethylene-glycol. Braz. J. Vet. Res. Anim. Sci. [online]. 1999, vol.36, n.5, pp. 00-00. ISSN 1678-4456. http://dx.doi.org/10.1590/S1413-95961999000500009.
The objetive of this study was to identify the better dose between 300 (n = 20), 400 (n = 21) and 500 IU (n = 21) of FSH/LH to stimulate Nelore heifers. The superovulation treatment started on day 10 (D0 = estrous) of the estrous cycle in 8 decreasing aplications for 4 days. The embryo recovery was achieved on day 6.5 after the first artificial insemination. The superovulatory response for 300, 400 and 500 IU FSH/LH was follicles (15.12, 15.76 and 14.94); corpus luteum (10.68, 11.55 and 10.81) and transferable embryos (5.20, 1.81 and 2.76). The 300 IU of FSH/LH group presented the best results in regard to transferable embryos. The transferable embryos were cryopreserved by one-step method with 1.5 M of ethylene-glycol, resulting in 8 pregnancies (7.5%) of 106 embryos transferred by non-curgical method. The 300 IU of FSH/LH presented better superovulatory response in comparison with 400 and 500 IU in Nelore heifers. The transfer of Bos taurus indicus embryos cryopreserved by one-step method in 1.5 M of ethilene glycol was not efficient.
Palavras-chave : Superovulation; Embryos; Ethylene-glycol; Cattle.