Pregnancy diagnosis in the ewe.

A total of 378 ewe lambs were evaluated for signs of pregnancy using five methods of detection. The methods used were breeding mark, rectal-abdominal palpation, an intrarectal Doppler instrument and two ultrasonic devices, the Scanoprobe and Scanopreg (Model 738) for sheep. Accuracies of pregnancy diagnosis based on grease marks at mating vs lambing results were 65.7% in 1976 and 75.5% in 1977 (P less than .05). Accuracy of diagnosis using the rectal-abdominal palpation technique was 62.7%. The overall accuracy on the same ewes using the intrarectal Doppler device was 72.7%. The ewes were examined when they were from 60 to 96 d of gestation using the two rectal probes. Seven ewes died from peritonitis and six aborted following pregnancy detection using the rectal instruments. Accuracy using the Scanoprobe device was 89.1% for ewe lambs that ranged from 69 to 103 d pregnant. The total accuracy achieved when the same ewes were evaluated at 78 to 112 d of gestation using the Scanopreg device was 94.8%.