Variation in Type Appraisal Scores Due to Sire and Herd Effects
L. D. VanVleck · Journal of Dairy Science · 1964
Type appraisal scores on about ],400 two-year-old and 4,080 older cows for 34 management and type characteristics were analyzed to determine the relative influence of sire and herd effects.Most traits could be scored in from three ¢o five categories.Estimates of within herd heritability were less than 10% for most traits.Components of variance for herd effects were also less than 10% for most traits.Exceptions are listed below.The management traits of resistance to mastitis and ketosis and of milking speed had heritabilities of about 25%.The body characteristics of dairy character, shoulder tightness, depth of body, and upstandingness also had heritability estimates of 20% or slightly greater.Heritability estimates for levelness of udder floor, depth of udder, strength of rear and fore udder attachment also were in the region of 25%.