Aerial contamination
Least important source of bacteria in milk
Few bacteria carried into milk by air entering the milking machine.
Cowsheds/ parlors do not exceed 200 bacteria / litre of air.
Organisms in parlor air; 1) Micrococci, 2) Coryneforms, & 3) Bacillus spores.
Few numbers of Streptococci and Gram-negative bacteria also observed.