Short Luteal Phases

Ruminants usually have a short luteal phase following first ovulation or first estrus at puberty or after parturition. In goats, short luteal phases are a problem in animals that are superovulated in preparation for embryo transfer. Premature uterine secretion of PGF2a is responsible for the short luteal phase in both cows and ewes.[1,2,9] Pretreatment of anestrous cows with a progestogen usually results in formation of a corpus luteum with a normal functional life span, in response to weaning or injection of gonadotropins, and increased numbers of receptors for progesterone in the uterus on day five after estrus. Upregulation of uterine progesterone receptors appears essential to normal timing of secretion of PGF2a. Understanding the function of progesterone in normalizing length of the estrous cycle has enabled development of methods to initiate normal cycles in anestrous cows, with normal fertility when cows are bred at the induced estrus.[9]

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