Mastitis Streptococci in Bulk Milk

A technique for examining bulk milk, by cultural and microscopical means, for evidence of mastitis among the cows is described. To demonstratea light contamination with haemolytic streptococci, cultural examination of gravity cream is advocated, whilst, if much significance is to be attached to the actual count, whole milk should be cultured. 2. Forty–two samples of Certified milk from sixteen producers wereexamined, and twenty–four of these contained beta-haemolytic streptococci when whole milk was cultured. Twelve of these herds were examined on three occasions during fifteen months, and samples from only two were free frombeta-haemolytic streptococci at every test.