DYNAMICS AND REGULATION OF BULK MILK SOMATIC-CELL COUNTS

Somatic cell count (SCC) in milk is inversely related to dairy cow pro ductivity and milk quality. In an effort to improve product quality, a nd indirectly farm productivity, regulatory limits on somatic cell cou nts have been established by many of the major dairy producing countri es. The purpose of this paper was to assess the impact of regulations on bulk milk somatic cell counts in Ontario and to assist producers in meeting regulatory limits through development of prediction models. T hrough the use of a transfer function model, provincial SCC was found to have dropped by approximately 60,000 as a result of the reduction p rogram. Limits of the regulatory program, seasonality and herd charact eristics were found through time series cross-sectional models to have an impact on prediction of SCC at the farm level, but the major influ ence was historical SCC levels.