ONTARIO BULK MILK SOMATIC-CELL COUNT REDUCTION PROGRAM - PROGRESS ANDOUTLOOK

The objective of this study was to describe the results of the ongoing somatic cell count (SCC) reduction program in Ontario, Canada and to provide an outlook regarding the possible scenarios beyond the final s tages of the current reduction program. The data were from all of the approximately 9500 farms in the province of Ontario during the last 10 yr and included monthly data for kilograms of milk sold, mean milk co mponent measurements, and milk quality measurements (bulk milk SCC, pl ate loop count, and inhibitor presence). Four of five steps in the con trol program had a significant impact on the mean monthly bulk milk SC C. The total decrease in mean SCC that was attributable to the program was approximately 80 x 10(3) cells/ml. The monthly occurrence of inhi bitor violations increased significantly. Cross-classification of the annual mean bulk milk SCC and the incidence of inhibitor violations in dicated that the incidence specifically increased for farms with a rel atively high bulk milk SCC. In 1994, bulk milk SCC increased, primaril y because of farms that had a mean bulk milk SCC between 150 x 10(3) a nd 450 x 10(3)/ml. The small relative contribution of farms with highe r bulk milk SCC was due to their relatively low production and the sma ll number of farms in those classes. The Ontario SCC reduction program was initially successful in the reduction of mean bulk milk SCC. Furt her reduction will require the active participation of farms with a re latively low bulk milk SCC. Not only is it necessary to penalize farms that exceed thresholds, but also an incentive to prevent farms with g ood udder health management from increasing bulk milk SCC is of great importance. The increase in inhibitor violations is of concern and req uires further attention.