BACTERIAL COUNTS OF BULK MILK FOR INTERSTATE SHIPMENT

Abstract

During this investigation single samples were collected from 773 milk cans, three samples from each of 416 farm bulk tanks, six samples from each of 158 farm pick-up trucks, single samples from 49 storage vats, twelve samples from each of 98 transport trucks, and single samples from 77 storage tanks. Of the samples collected, 96% had counts under 200,000; 1.9% had counts of 200,000 – 300,000; 0.7% had counts of 300,000 to 400,000 and 1.4% had counts in excess of 400,000 per ml. The bacterial count finding on pumped milk indicated that milk passage through pumps did not appear to contribute to subsequent high counts through the break-up of bacterial clumps which may have been present. When bacterial counts were correlated with observations of the sanitary conditions of milk handling, the data reaffirmed that laxity in cleaning, bactericidal treatment or cooling will be reflected in the bacterial count and may result in the shipment of raw milk having counts in excess of 200,000 per ml.