THE ASSOCIATION BETWEEN CLINICAL DISEASE, PRODUCTION AND CULLING OF HOLSTEIN-FRIESIAN COWS

Abstract
A study of the association between disease occurrence, level of production and culling in 18 southern Ontario purebred Holstein-Friesian herds was conducted. The rate of culling increased by approximately 3% per year of age (P < 0.05). Culled cows had lower milk production, were milked longer and had longer calving intervals in the lactation completed prior to culling, than their herdmates (P < 0.05). After control for age effects, the associations between production level and culling were not significant. Culled cows had a lower rate of ketosis and higher rates of foot problems and dystocia in the last completed lactation than nonculled cows. Culled cows had higher rates of nonparturition-related metritis and lower rates of ovarian cystic disease than nonculled cows. Despite the differences in disease occurrence and level of production between culled and nonculled cows, clinical disease(s) observed by veterinarians and poor production explained only a small proportion of culling in dairy cows. Key words: Association, culling, disease, production, Holstein-Friesian