Superstimulation of ovarian follicular growth with FSH, oocyte recovery, and embryo production from zebu (Bos indicus) calves: effects of treatment with a GnRH agonist or antagonist.

摘要

30 Brahman calves, aged 3 months (140±3 kg), were: (1) not treated from day -8 to day -1 and then superstimulated with FSH from day 0 to day 2 (controls), (2) implanted with 3 deslorelin implants from day -8 to day 3 and superstimulated from day 0 (GnRH agonist), or (3) injected twice daily with cetrorelix from day -3 to day 2 and superstimulated from day 0 (GnRH antagonist). All calves were ovariectomized on day 3 to determine follicular response and to recover oocytes. Before treatment with FSH,the GnRH-agonist heifers had higher concentrations of plasma LH than control heifers (0.30±0.01 vs. 0.17±0.02 ng/ml; P<0.001); GnRH antagonist heifers had reduced plasma LH concentrations (0.13±0.01 ng/ml; P<0.05). The surge release of LH that occurred during treatment with FSH in controls was not seen in the 2 treated groups. All heifers had large numbers of follicles >=2 mm (～60 follicles) after superstimulation. There was no difference among groups in the number of follicles, the number of oocytes recovered and cultured, fertilization and cleavage rates, or in developmental rate to blastocysts.