The ultra-sound fat-testing procedure for the cattle uses the same principals of sending out and receiving sound waves to learn what is under the skin as it does for human applications. It is easy, accurate, and painless for the cattle.  The qualified assessor comes to the farm about three times every year and choose the testing site just forward on the rump beside the back bone. This has been determined historically as being the most indicative place on a cattle carcass for uniformity of fat cover distribution.