The comparative incidence of subclinical bacterial bovine mastitis in 17 herds when using two sets of diagnostic criteria.

On the single examination of 6804 quarter milk samples during a routine mastitis survey in 17 herds it was found that whereas 12,4% of quarters were diagnosed as subclinically mastitic when using the IDF standard set of diagnostic criteria, only 2,4% were positive when applying the additional criterium of a positive test for bovine serum albumin. The remaining 10% of quarters were then classified as being affected with septic inflammation of the ducts. The ratio of true subclinical septic mastitis to duct and test canal infections is recorded and the implications of the findings are briefly discussed.