Visualization of male and female characteristics of bovine fetuses by real-time ultrasonics.

Sexing of bovine embryos can enhance breeding programs at a rather early stage of pregnancy. The accurate predictability of the sex of the fetus can, for example, speed up breeding programs and allows an early selection of pregnant heifers for certain purposes according to the sex of their fetuses. Ultrasonic images were produced by a real image-producing sector scanner that was inserted per rectum into pregnant cows and heifers. Scrotal swellings and mammary teats were recognizable, allowing sexing of the fetuses between gestational day 73 and 120. The tests carried out showed an accuracy of 94%. Forty-nine of 52 ultrasonic diagnoses were confirmed as correct by subsequent calvings.