ONTARIO BULK MILK SOMATIC-CELL COUNT REDUCTION PROGRAM .1. IMPACT ON SOMATIC-CELL COUNTS AND MILK QUALITY

The objective of this study was to evaluate the bulk milk SCC control program in Ontario and to observe the effect of the program on milk components and milk quality. The data were from the approximately 9500 farms in Ontario, Canada. Data on milk quality, milk components, and kilograms of milk produced were collected monthly from January 1985 through September 1991. The SCC data had a significant seasonal pattern. The expected lowest mean SCC occurred in April, and the expected highest mean SCC occurred in October. The SCC control program had a significant impact on the mean monthly SCC. A decrease of approximately 58 X 10(3) cells can be attributed to the program. Percentage of fat and lactose increased significantly with decreasing bulk milk SCC. Bulk milk SCC had very little effect on protein percentage. In herds that produced milk with lower SCC, we observed significantly lower plate loop count, lower incidence of inhibitor violations, and lower freezing point of the milk.