Coliform Organisms in Certified Milk

The udder as a possible source of coliform organisms in milk

1. It seems to be the general opinion of veterinary contributors on the subject that infection of the udder with coliform organisms is rapidly followed by clinical symptoms of mastitis, and marked changes in the appearance of the secretion. There would therefore appear to be little danger of contamination of bulk milk from such sources except during the few hours between infection and the appearance of the clinical symptoms.

2. Injury to the teats or quarters may result in infection of milk with coliform organisms owing to the difficulty of thorough cleaning of the malformed tissue.

3. Several cases of infection of quarters in the entire absence of clinical or other symptoms of disease have been cited. There is no evidence that such cases can be classed as subclinical forms of the disease as is the case in streptococcic mastitis. The evidence in two cases cited indicates that milk drawn from a quarter can remain infected with coliform organisms for a considerable period with no apparent clinical or other symptoms of disease.

4. There is sufficient evidence to warrant the examination of quarter samples in cases where infection of bulk milk with coliform organisms from other more common sources appears to be unlikely.