Heritability of Milk Yield at Different Herd Means and Variance for Production

Abstract

Heritability of milk yield was estimated at three levels each of herd mean and standard deviation of Modified Contemporary Average for both Holsteins and Jerseys. As herd mean increased, Holstein heritabilities were erratic (.222, .163, and .206), and Jersey heritabilities increased (.246, .291, and .331). As herd standard deviation increased, Holstein heritabilities increased slightly (.178, 193, and .206), while Jersey heritabilities increased substantially (.254, .293, and .371). Heritabilities were consistently larger for Jerseys than for Holsteins.