GENETIC AND PHENOTYPIC PARAMETERS OF LIFETIME AND STAYABILITY TRAITS IN DANISH DAIRY BREEDS

Data on 216,428 Danish Red, 798,152 Danish Friesian and 232,953 Danish Jersey cows were used to estimate phenotypic and genetic parameters f or actual and production-corrected survival traits and for milk produc tion. Genetic effects of imported breeds were also estimated. Phenotyp ic trends in days in mill; were similar for Danish Red and Danish Frie sian, and showed influences of the milk quota system, whereas Danish J ersey showed a continuous downwards trend. Significant additive and no n-additive effects due to imported breeds were found. Heritabilities d iffered between breeds, ranging from 0.072 to 0.122 for actual continu ous lifetime traits, and from 0.048 to 0.076 for production-corrected continuous lifetime traits. Binary stayability traits showed lower her itability. Genetic correlations between milk production and actual or production-corrected days in milk were 0.63 and 0.31 respectively. Gen etic correlations between binary stayabilities and continuous lifetime traits were high (>0.78), which indicates that stayabilities can be u sed as early predictors of the lifetime traits.