Epidemiological and genetical studies in Norwegian pig herds. V. Estimates of heritability and phenotypic correlations of the most common diseases in Norwegian pigs.

A genetic analysis was performed on disease registrations from 70 Norwegian pig herds. This analysis was complicated by the small degree of cross classification of dams and sires across herds, and the relatively sparse use of artificial insemination. Herd effects seemed to be responsible for much of the variation in disease frequencies. The estimated heritabilities were relatively low. The results of this investigation also revealed positive phenotypic correlations between the investigated diseases.