Detection of pregnancy in ewe lambs by A-mode ultrasound

The objectives of the study were to determine the time required to learn the detection of pregnancy using a technique of A-mode ultrasound and then to test the method on a commercial flock of 181 ewe lambs. Nine-and-a-half hours were spent learning the technique. The trial on the commercial flock showed that of 113 ewe lambs which produced offspring 98 were correctly predicted as pregnant and 15 were wrongly predicted as not pregnant. Of 68 ewe lambs which did not produce offspring 47 were correctly predicted as not pregnant and 21 were wrongly predicted as pregnant. The practicalities of the technique and the consequences of the test errors are discussed.