Oestrus, time of ovulation, ovulation rate and conception rate in progestagen-treated ewes given Gn-RH, Gn-RH analogues and gonadotrophins

摘要: The influence of Gn-RH, hCG and a PMSG-hCG mixture (PG600) on the time ovulation, ovulation rate occurrence oestrus in ewes treated with progestagen-impregnated sponges for 12 days examined. effects Gn-RH analogues plasma LH, oestrus, conception were also investigated. Six separate experiments carried out. When 50 micrograms given 24 h after sponge removal occurred 44--46% within all by 34 h. was more potent synchronizer than hCG. Both PG600 reduced incidence overt oestrus. had this effect during February May but not August September. 2 before significantly increased rate. display affected suppressed 43-69% an analogue at removal. Ovulation 50-62% 30-35 injection analogues, regardless their administration. release LH response to one influenced presence vagina. or 63 62% mated became pregnant compared 70% control ewes.