What weighting should be given to BRD resistance in selection decisions?

Multiple-trait selection indexes should include all of the economically-relevant traits that influence the profitability of beef cattle production. They provide an economic evaluation of the genetic differences among sires, and an objective way to determine likely differences in the profitability of progeny from different sires. In contrast to the swine, poultry, sheep, and dairy cattle industries, in which economic indexes are a critical component of selection strategies, the US beef industry has made little use of selection indexes (Garrick and Golden, 2009). Some breed associations have produced and published generalized indexes for their breeders, but details concerning the criteria and relative economic weights are not readily available. Wide disparities in the costs of production and different marketing strategies exist throughout the US, making it unlikely that the economic values used in these generalized indexes are universally applicable. However, correlations among breeding objectives that incorporate local prices conditions are generally quite high, making an approximate index perhaps a preferable option to no index at all.