Profitability Index for Sires

Abstract

A profitability index for evaluation of sires on predicted lifetime production of daughters and their progeny was developed from sire evaluations for milk yield, fat yield and stayability. Indices of milk and stayability for 1st lactations were used to calculate proofs for stayability in later lactations. Predicted milk yields were adjusted to the actual age when the records would be made. Breed averages were calculated from records of daughters of 1192 Holstein-Friesian sires in the Northeast Artificial Insemination Sire Comparison. Proofs for stayability through the 1st lactation and indexes for stayability in later lactations were used to describe opportunities for genes of the sire to be expressed in a specified year of 1st or later generations over 15 periods, 13 mo. each. These opportunities gave the expected number of lactations from 1 conception. Multiplying expected number of lactations by milk and fat proofs and net profits per kilogram estimates total economic returns from a single conception. Examples show that stayability may be important in evaluation of sires. Correlation between milk proof and economic evaluation was 0.77.