Mate selection by selection index theory.

Mate selection by selection index prediction of total merit in expected progeny is proposed as a rational basis for making recommendations in the choice of a bull to which a cow may be mated. Growth in USA of service programs recommending bulls to particular cows has motivated the need to rationalize mate selection processes. This paper illustrates that mate selection on the basis of highest index value for expected progeny among potential mates can justify special mate selection programs, when a nonlinear relationship exists between at least one trait in the index and merit.