DESCRIPTIVE EPIDEMIOLOGIC-STUDY ON CULLING AND DEATHS IN 8 DAIRY HERDS

Objectives To describe the production and reproduction characteristics of the population under investigation and to compare them with the ta rget population of non-seasonally calving dairy herds, to describe the pattern of culling with respect to length of productive life and leng th of time after calving, and to identify stages of the production cyc le that are associated with increased risk oi culling from the dairy h erd. Design A longitudinal population study of eight non-seasonally ca rving dairy herds in the Camden district of New South Wales. Results T he production and reproduction characteristics of this population were broadly similar to herds participating in the New South Wales Agricul ture Dairy Herd Improvement scheme. In agreement with recent surveys, risk of culling increased with increased parity. This was accounted fo r specifically by increased risk of culling for calving disorders, rep roductive tract lesions, and disorders of the udder. Risk of culling f or failure to conceive appeared to remain constant throughout producti ve life. The overall risks for culling were greatest during the first 9 days after calving and 300 days after carving. Conclusion Reducing t he incidence of calving-associated disorders, attention to reproductiv e management and control of herd mastitis offer opportunities to reduc e involuntary culling rates in this population.