Evaluation of two prostaglandin products in pregnant sows for initiation of Luteolysis

Kansas State University Swine Research. We used 66 pregnant sows to compareserum progesterone concentrations follow- ing a single injection of either saline or one of two prostaglandin F2a products ap- proved for use in swine. Pregnant sows in a commercial swine farm were assigned to one of the three groups in a completely randomized design balanced across treat- ment for parity and day of gestation. Each sow received a single intramuscular dose(2 mL) on d 111, 112, or 113 of gestation. Mean serum progesterone concentrations were decreased significantly at 6 and 12 hours after dose administration of both prostaglandin products. However, these effects did not differ. Serum progesterone concentrations did not decrease signifi- cantly at any time in the control group.This indicates that regression of corpora lutea was initiated at the same time by both prostaglandin products.