Effect of repeated horse anterior pituitary extract treatment on ovulatory response in the ewe
Boland, M.P.; Gordon, I.
Veterinary Record 111(17): 391-392
1982
ISSN/ISBN: 0042-4900 PMID: 6891137 Document Number: 193153
10 crossbred Suffolk, 9 Galway and 6 Dorset Horn ewes were treated for 14 days with an intravaginal sponge containing 30 mg FGA, plus an injection of 45 mg horse anterior pituitary extract on each of the last 3 days of FGA treatment. Ewes were mated on detection of oestrus, and at 12-h intervals thereafter until the end of oestrus. Laparotomy was performed 96 plus or minus 2 h after FGA withdrawal. 23 of the ewes were treated similarly 2-6 months later, and 7 were treated a 3rd time, about 4 months after the 2nd treatment. For the 1st, 2nd and 3rd treatments, the percentage of ewes showing oestrus was 84.0, 78.2 and 85.7 resp., the number of ewes ovulating 23, 18 and 6, ovulation rate 8.1, 4.6 and 6.8 (all ewes) and 8.8, 5.9 and 8.0 (ewes ovulating), the number of eggs recovered 132, 48 and 11, (65.3, 45.3 and 22.9% resp. of eggs ovulated), and the percentage of eggs fertilised 56.1, 72.9 and 90.9. The ovulation rate was "low" after the 2nd treatment within 2 months, but "satisfactory" if a longer period elapsed before the 2nd treatment.