Abstract
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 <1 ng/ml earlier (P<.02) than A donors. Plasma estrogen (E) concentrations, the E response and plasma E:P4 ratio were significantly influenced by breed (P<.Ol) and superovulatory treatment (P<.Ol). Plasma cortisol concentrations were greater in A than in B donors (P<.05). Total number of follicles and medium sized (MF) follicles were affected by a breed x treatment interaction (P<.Ol). Breed and superovulatory treatment influenced (P<.Ol) the number of large follicles (LF). Follicular growth was greater in B (P<.Ol) than in A donors and was similar with either superovulatory treatment (P>.20). Estrus and the LH surge were suppressed in A as compared to B donors (P<.Ol). In Experiment 11, plasma P4 concentrations did not differ between high and low responders (P>.10); however, plasma E concentrations, the E response and plasma E:P4 ratio were significantly affected by the type of superovulatory response (P<.05). FSH-P increased intrafollicular E concentrations and the E:P4 ratio in LF and MF (P<.Ol) as compared to controls. Progesterone concentrations were lower in FSH-P- stimulated MF than in controls (P<.Ol). Testosterone (T) concentrations were affected by a treatment x follicle size interaction (P<.Ol); there was a tendency (P<.06) for greater insulin-like growth factor-1 (IGF-1) concentrations in LF after FSH-P stimulation. Across FSH-P-stimulated follicles, superovulatory response type did not influence concentrations of E, P4 or the E:P, ratio (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.
Rodriguez, Harold Felipe (1995). Endocrine profiles and ovarian responses in Bos indicus embryo donors after ovarian stimulation with two different superovulatory treatments. Texas A&M University. Texas A&M University. Libraries. Available electronically from
https : / /hdl .handle .net /1969 .1 /DISSERTATIONS -1560063.