The effects of progesterone and oestrogen treatment in heifers on oestrous cycle control and plasma progesterone levels.
Data are presented on the effects of a short-term progesterone treatment for oestrous cycle control in cattle. Progesterone was administered by intravaginal sponge pessaries inserted for a 10-day period. Progesterone pessaries alone did not affect oestrous cycle length or corpus luteum function at either early (day 2) or midluteal (day 12) cycle stages. However, when progesterone (250 mg) and oestradiol benzoate (7-5 mg) were given intramuscularly on the day of pessary insertion corpus luteum development was inhibited in animals treated at day 2 and was regressed in animals at day 12. This combined oestrogen-progesterone treatment efficiently controlled oestrous cycle length.
D000818:Animals; D002417:Cattle / Q000502:physiology*; D004958:Estradiol / Q000494:pharmacology*; D004973:Estrus Synchronization / Q000187:drug effects*; D005260:Female; D003341:Luteolysis / Q000187:drug effects; D011247:Pregnancy; D011374:Progesterone / Q000097:blood* / Q000494:pharmacology
D011374:Progesterone; D004958:Estradiol