STAPHYLOCOCCI SHED IN MILK OF FRESHENED HEIFERS FOLLOWING THE USE OF MILKING MACHINES

The transmission of staphylococcal strains prevalent in the milk of 3 dairy herds to their respective, freshened heifers following the use of the milking machine was traced by phage typing. The introduction of new cows to 1 herd provided 1 staphylococcal strain that predominated in the herd. Some heifers acquired staphylococcal strains identical to those found in the herd within 1 wk following the use of the milking machine.