THE REDUCTION OF THE MICROFLORA OF MILKING MACHINE INFLATIONS BY TEAT DIPPING AND TEAT CUP PASTEURIZATION1

Teats were dipped immediately after milking in (a) an iodophor diluted to contain 1.0 per cent available iodine; (b) P.V.P.—Hibitane, containing 1.6 per cent Hibitane (Chlorhexidine); and (c) P.V.P.—Hibitane containing 0.5 per cent Hibitane. After each cow was milked the teat cups were rinsed briefly and “pasteurized” at 165–170°F for 15 seconds. Teat-dipping alone reduced dramatically the number of micrococci on the inflations but was only partially effective in reducing the percentage of inflations carrying haemolytic staphylococci, except when the 1.6 per cent P.V.P.—Hibitane was used. This material was, however, somewhat irritating to the teats. Teat cup pasteurizing alone partially reduced the percentage of teat cups carrying haemolytic staphylococci, but had little effect on the number of micrococci initially present on the inflations. It appears that the combination of these simple practices will go far towards eliminating the teat-skin and milking machine inflations as reservoirs of haemolytic staphylococci.