Seasonal and Processing Influences on Bacterial Count of Raw and Processed Milk

An increase in total counts of raw milk was detected during summer in comparison to winter. The higher summer temperature did not affect the numbers of coliforms and staphylococci. The microbial contamination of pasteurized milk did not change significantly during the year. All bacterial counts increased during the flow of milk through the various systems of the dairy plant before the pasteurizer. It was shown that pipe lines could cause contamination of milk, especially at the beginning of flow after the line was temporarily shut down. A correlation between numbers of coliforms and staphylococci was found for both raw and pasteurized milk.