NET MERIT AS A MEASURE OF LIFETIME PROFIT: 2003 REVISION

Authors: Vanraden, Paul; SEYKORA, A - UNIV OF MINESOTA

Submitted to: AIPL Research Reports
Publication Type: Government Publication
Publication Acceptance Date: 7/22/2003
Publication Date: N/A
Citation: N/A

Interpretive Summary: Selection of animals to be parents of the next generation of U.S. dairy cattle should be more accurate if all traits of economic value are included in the net merit (NM$) index. The following traits have been added to NM$ as of August 2003: daughter pregnancy rate (cow fertility), daughter calving ease, and service sire calving ease. Economic values of yield traits (milk, fat, and protein), productive life (longevity), somatic cell score (mastitis resistance), and conformation traits (udder, feet and legs, and body size composites) also were updated. Milk component prices were revised to make the cheese merit and fluid merit indexes useful for more dairy producers. A profit function approach lets breeders select for many traits by combining the incomes and expenses for each trait into an accurate measure of overall profit. When buying breeding stock or semen, producers should use the lifetime merit index that corresponds to the market pricing that they expect to receive several years in the future.

Technical Abstract: Selection of animals to be parents of the next generation of U.S. dairy cattle should be more accurate if all traits of economic value are included in the net merit (NM$) index. The following traits have been added to NM$ as of August 2003: daughter pregnancy rate (cow fertility), daughter calving ease (effect of maternal grandsire on cow calving ease), and service sire calving ease, and). Economic values of yield traits (milk, fat, and protein), productive life (longevity), somatic cell score (mastitis resistance), and conformation traits (udder, feet and legs, and body size composites) also were updated. Milk component prices were revised to make the cheese merit and fluid merit indexes useful for more dairy producers. A linear approximation of the nonlinear function is used to calculate the official values for the three lifetime merit indexes. The profit function approach lets breeders select for many traits by combining the incomes and expenses for each trait into an accurate measure of overall profit. When buying breeding stock or semen, producers should use the lifetime merit index that corresponds to the market pricing that they expect to receive several years in the future.