Factors associated with productivity in Canadian sheep flocks.

A mail survey of Canadian sheep flocks registered on the Record of Performance program was conducted, and the association of management practices and diseases with productivity was studied using multiple regression techniques. The relationships between management practices and diseases of lambs which were associated with production were also investigated using discriminant analysis. Flocks in the maritimes had a lower average flock productivity than those in Ontario-Quebec and the western provinces. In purebred flocks, the average adjusted weight at 100 days of age was higher than in other types of flocks, and the prevalence of scours was lower. At the herd level, the rates of pregnancy toxemia and vaginal prolapse were associated with heavier lambs, while the average daily weight gain between 50 and 100 days of age was lower in herds affected by scours and starvation. Using pasture and bush as winter housing was also detrimental to lamb productivity. No management practices discriminated between case and control flocks for scours and starvation in lambs. It was concluded that the reasons for the geographic differences should be investigated as should the management differences between purebred and other producers. Prevention of scours and starvation in lambs should be given priority in order to increase productivity.