Progeny testing
Judging a bull's breeding value from the measured performance of his daughters or offspring.
Also: progeny test, daughter proof
Progeny testing ranks bulls by what their offspring do rather than by how the bulls themselves look. A young dairy bull is mated to cows in many herds, and when his daughters have finished their first lactation their milk, fat and protein yields, along with traits such as udder shape and fertility, are compared with those of other cows in the same herds. The result, called a proof, decides whether his semen is then used widely. It is reliable but slow, taking about five years from the bull's birth. Since about 2009 genomic selection has replaced much of it in dairy breeding, though offspring records still check the genomic predictions.