Control of Parturition in the Sow Using Progesterone and Prostaglandin

The effect of progesterone and prostaglandin administration on the timing of farrowing was studied in three groups of 25 sows each .. Progesterone treatment (100 mg/day) on days 112, 113 and 114 of gestation (group I) significantly prolonged the gestation length to 116 A±0·4 (mean±s.e.) days compared to the control sows (group III; 115·5 ±O· 2; P < 0 ·05). Administration of prostaglandin (200 I1g Cloprostanol intramuscularly) on day 115 of gestation following progesterone treatment (group II) resulted in a gestation length of 116 ·0 ±0·1 days, with the sows farrowing 25 ·4± 1 ·0 h after the prostaglandin injection. 80 % of the sows farrowed between 0800 and 1700 h of day 116 of gestation.