Endocrine profiles and ovarian responses in Bos indicus embryo donors after ovarian stimulation with two different superovulatory treatments

Vita.Endocrine and ovarian responses in Brahman cows stimulated with two different superovulatory treatments were examined. In Experiment 1, plasma progesterone (P4) concentrations were not affected (P>.40) by breed (Brahman: B, Angus:A), superovulatory treatment (FSH-P, SuperOv) or their interaction. After prostaglandin F2,,, B donors reached P4 concentrations .20). Estrus and the LH surge were suppressed in A as compared to B donors (P.10); however, plasma E concentrations, the E response and plasma E:P4 ratio were significantly affected by the type of superovulatory response (P.30) but follicle size category significantly affected P4 concentrations and the E:P4 ratio (P<.Ol). Both, superovulatory response type and follicle size category affected T concentrations (P<.Ol). Also, concentrations of IGF-1 were greater in follicles from high responders (P<.Ol) as compared to those from low responders. In summary, follicular growth was similar with either superovulatory treatment and administration of FSH-P altered plasma and follicular endocrine profiles in Bos indicus cows