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Submitted to: AIPL Research Reports
Publication Type: Government Publication Publication Acceptance Date: 2/7/2017 Publication Date: 2/7/2017 Citation: Van Raden, P.M. 2017. Net merit as a measure of lifetime profit: 2017 revision. AIPL Research Reports. NM$6 (2-17). Interpretive Summary: Technical Abstract: Economic values in net merit (NM$) were updated in April 2017, cow livability (LIV) was included as a new trait, and body weight composite (BWC) replaced body size composite (BSC). Cows that die or are euthanized on the farm generate no beef income and may have more health expenses than cows that are culled. Research by Holstein USA (2016) redefined BSC to predict body weight more accurately using recent weight and linear type data from research herds with measured feed intake. These changes shifted some economic value from productive life (PL) to LIV, and the selection against BWC is larger than that against BSC in the 2014 index. Most other traits received slightly less relative emphasis because LIV and BWC were emphasized more. Milk component prices were revised with a slight shift from protein to fat and lower milk price than forecast in 2014 NM$. Other economic values were updated very little. For recent bulls, the 2017 and 2014 NM$ indexes were correlated by 0.989. The 2017 revision should lead to healthier and more efficient cows. An increase in genetic progress worth $2.5 million/year is expected on a national basis, assuming that all of the changes are improvements and that all breeders select on NM$. |
