Early pregnancy diagnosis in sows by ultrasonic linear electronic scanning.

A rapid and accurate technique for pregnancy diagnosis in sows has been developed. A portable ultrasonic linear electronic scanner was used in conjunction with 3.5 MHz multitransducers. The scanner employed ultrasonic waves to generate a two-dimensional image of an interior cross-section of an animal and the image was displayed on a TV monitor. The tip of the transducer was placed in contact with the lower flank of the standing sow about 5 cm posterior to the navel and just lateral to the nipple line directing toward the uterus. Results of tests conducted under controlled conditions on a farm, using 145 sows, proved that accuracy of the technique approaches 100% for diagnosing pregnancy from day 22 of gestation through term. The time of feeding before scanning did not affect the accuracy of pregnancy diagnosis.