Do Livestock Producers Use Selection Indices?: Evidence from US Dairy Bull Prices

I use a hedonic model to estimate how US dairy producers valued the value production, health, and physical traits of over 24,000 dairy bulls sold between 2000 and 2010. To guide producers toward more sustainable cattle, both governments and breed associations suggest incorporating new traits into selection indices. To understand the influence of selection indices on how producers value traits, I compare the valuations derived from a hedonic model to the valuations assumed in the dairy bull selection index Net Merit. In a selection index constructed from the hedonic analysis, I find that physical traits independent of production and health are nearly 50% of the index. In the USDA’s selection index, these physical traits make up less than 20%. While the size of the cow factors negatively into the USDA index, body size factors positively into the hedonic index. Since body size is strongly correlated to methane emissions, these findings have significant implications for how breeding decisions may contribute to climate change and whether changing selection indices will meaningfully impact breeding decisions.