Control of the time of parturition in sows with prostaglandin F2alpha.

Pregnant gilts and sows were given a single intramuscular injection of from 5-10 mg of prostaglandin F2alpha-tromethamine salt (dependent on liveweight) on day 111, 112 or 113 of pregnancy (first day of estrus = day 0) to induce parturition. When injected on day 111, 44% of the pigs farrowed within 40 hours compared with 93% injected on days 112 or 113. The mean time to the induced parturition was 27.3 +/- 4.7 hours. Signs of discomfort were observed during the first hour posttreatment but there were no apparent effects on lactation or on the mothering ability of the dams after farrowing.