Time of ovulation in goats (Capra hircus) induced to superovulate with PMSG
- 1 July 1988
- journal article
- research article
- Published by Bioscientifica in Reproduction
- Vol. 83 (2) , 747-752
- https://doi.org/10.1530/jrf.0.0830747
Abstract
The timing of ovulation in feral goats treated with 1200 i.u. PMSG .+-. 50 .mu.g GnRH was studied by repeated laparoscopy. Experiment 1 established that superovulation began as early as 30 h after withdrawal of progestagen-impregnated sponges and was not completed at 54 h if goats received PMSG alone. GnRH synchronized ovulation, leading to 91% of ovulations appearing between 36 and 48 h after sponges were withdrawn. Experiment 2 established that superovulation continued until up to 77 h in goats treated only with PMSG. The stress of repeated laparoscopy appeared to delay or abolish ovulation in some females. The mean (.+-. s.e.) ovulation rate was greater in goats treated with GnRH (12.7 .+-. 1.3) than in those that received PMSG only (9.7 .+-. 1.1; P < 0.05). Out of 47 of the females in Exp. 1, 43 had one or more corpora lutea at laparoscopy 24 h after withdrawal of progestagen. These early corpora lutea were associated with an increased concentration of plasma progesterone during the periovulatory period. Experiment 3 provided evidence that these corpora lutea arose before the withdrawal of progestagen-impregnated sponges.Keywords
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