Genetic and Herd-Year Variation in Type Traits of Brown Swiss Cows

Abstract

Type classification records of 15,697 Brown Swiss cows by 1955 sires in 852 herds were analyzed with a cross-classified (herd-year and sire of cow) model. Fractions of variance due to herd-year effects ranged from 8% for mammary system to 17% for body capacity. Within herd-year heritabilities ranged from 24% for feet and legs to 43% for final score. Descriptive traits were analyzed by the same model except that each category was treated as a binomial variable. Proportions of variance due to herd-year effects for the descriptive traits were generally below 10%. Heritabilities were generally below 15%.