Pregnancy diagnosis in Swine: a comparison of two ultrasound instruments

This investigation was designed to assess the sensitivity, specificity and positive predictive values of amplitude-depth and Doppler pregnancy detectors when utilized for pregnancy diagnosis of mated sows. Mated sows (n = 38) were tested daily from 15 to 45 days after mating for pregnancy with the ultrasound instruments. The same procedure was performed with nonmated sows (n = 10) 15 to 45 days after estrus. Both instruments were unreliable for pregnancy diagnosis between 15 and 22 days after mating. Between 23 and 45 days after mating the Doppler pregnancy detector was more specific and had greater positive predictive values. In contrast the amplitude-depth pregnancy detector was more sensitive during the same time interval.Serum estrone sulphate concentrations were determined in samples collected between 27 and 30 days after mating or estrus, as an alternate method of pregnancy diagnosis. Serum estrone sulphate concentrations were always equal to or greater than 0.5 ng/mL in the pregnant sows, while in the nonmated sows estrone sulphate concentrations were never more than 0.5 ng/mL serum.