The Relationship between Type Ratings of Ayrshire Females as Young Heifers and as Cows

Abstract

102 Ayrshire heifers at the W. Virginia Agric. Expt. Station have been rated for type starting at 6 or 12 months of age and at 6-mo. intervals thereafter until 4 or 5 yrs. of age. The 5 grades used were: Excellent, Very Good, Good Plus, Good and Fair. When these were coded 5, 4, 3, 2 and 1, respectively, the intra-animal standard deviation was 0.62 when the ratings were made before first calving and 0.65 for ratings given after calving. The correlations between the avg. of the several ratings of each heifer before first calving and the 1st and 2d ratings after calving were 0.37 and 0.4, respectively. The heifers were placed in 4 groups according to their avg. ratings before first calving and those group ratings compared with the avg. ratings of the same groups after calving. The low group remained the lowest following calving, while the high group still maintained the highest avg. score, but both averages were closer to the general mean. The 2 middle group averages changes very little following freshening. With improvement in and standardization of classification methods, particularly for heifers, the classification program may become valuable in helping breeders to cull individuals from their herds at an early age on a basis of type.