Synchronization of ovulation and fertility in weaned sows treated with intravaginal triptorelin is influenced by timing of administration and follicle size

A 100 μg dose of triptorelin was tested for synchronizing ovulation in sows. In Experiment 1, conducted in April through June, sows (n = 125) were assigned to Control (untreated), TG-96 (Triptorelin Gel (TG) given intravaginally at 96 h post-weaning), or TG-E (given intravaginally at estrus). To optimize AI timing, sows were inseminated at 2 and 26 h after estrus for Control and TG-E and at 8 and 32 h following TG-96. Ovulation by 48 h post-treatment tended to be affected by treatment (P = 0.08) and more (P < 0.05) TG-96 sows ovulated (57.9%) compared to Controls (34.2%), but TG-E (45.1%) did not differ (P > 0.10). Duration of estrus was reduced (P < 0.005) in TG-96 (51 h) and TG-E (58 h) compared to Controls (65 h). There was no treatment effect on farrowing rate (71%) or total born (10.4). Average follicle size