Response of the lactating and postweaning sow to gonadotropin releasing hormone (GnRH).
Clinical and endocrinological responses to administration of gonadotropin releasing hormone analog (LH-RH-A) during the lactation period and postweaning in the sow were investigated. Plasma LH concentrations in lactating sows rose immediately after administration of LH-RH-A. However, in postweaning sows the increase of LH level was more slowly. Three of 5 postweaning sows came into estrus and ovulated after LH-RH-A treatment. One sow exhibited a distinct LH response, but her ovaries remained quiescent. The remaining one with feeble estrus for a short period became cystic ovaries. Thus, LH response to GnRH in the sow seems to be higher during early lactation than at 2 days postweaning.
Ogasa
A
A
Department of Reproduction, Nippon Veterinary and Animal Science University, Musashino, Japan.
Tsutsui
T
T
Kawakami
E
E
Sone
M
M
Kawarasaki
T
T
Iwamura
S
S
D000818:Animals; D004958:Estradiol / Q000097:blood; D004971:Estrus / Q000187:drug effects; D005260:Female; D007987:Gonadotropin-Releasing Hormone / Q000031:analogs & derivatives / Q000494:pharmacology*; D007774:Lactation / Q000187:drug effects* / Q000502:physiology; D008183:Luteal Phase / Q000187:drug effects; D007986:Luteinizing Hormone / Q000097:blood; D010060:Ovulation / Q000187:drug effects; D011374:Progesterone / Q000097:blood; D013552:Swine / Q000502:physiology*; D014886:Weaning
D007987:Gonadotropin-Releasing Hormone; D011374:Progesterone; D004958:Estradiol; D007986:Luteinizing Hormone