Changes in the plasma concentrations of free and conjugated oestrogens in heifers after treatment to induce superovulation and the relationship with number of ovulations.
Oestradiol-17 beta and conjugated oestrone, oestradiol-17 beta and oestradiol-17 alpha were measured in peripheral plasma of heifers treated with PMSG/PGF-2 alpha to induce superovulation. Changes in the concentrations of each hormone were synchronous, the highest level being near oestrus. For a given number of ovulations the hormone with the highest concentration was total oestradiol-17 alpha, then came total oestrone, total oestradiol-17 beta and oestradiol-17 beta. For each oestrogen, the maximum preovulatory concentration measured was significantly correlated with the number of ovulations; the regression line for total oestradiol-17 alpha was twice as steep as that for oestradiol-17 beta. It is concluded that in animals treated to induce superovulation assay of total oestradiol-17 alpha gives a better induction of the number of follicles induced to ovulate than does the more conventional assay of oestradiol-17 beta.
D000818:Animals; D002417:Cattle; D015237:Dinoprost; D004958:Estradiol / Q000097:blood; D004967:Estrogens / Q000097:blood*; D004966:Estrogens, Conjugated (USP) / Q000097:blood*; D004970:Estrone / Q000097:blood; D005260:Female; D006064:Gonadotropins, Equine / Q000494:pharmacology; D010060:Ovulation; D010061:Ovulation Detection; D011460:Prostaglandins F / Q000494:pharmacology; D013480:Superovulation
D004967:Estrogens; D004966:Estrogens, Conjugated (USP); D006064:Gonadotropins, Equine; D011460:Prostaglandins F; D004970:Estrone; D004958:Estradiol; D015237:Dinoprost