[Quantitative cytological findings in mixed milk samples].

In two cow-houses (fifty cows in each), 5851 udder-quarter samples were subjected to cytological examination (by the Coulter Counter electronic computer) and to bacteriological examination during a ten-month period; the cytological examination was also performed with 141 can milk samples. The mixed samples in which the number of cellular elements does not exceed the level of 500 thousand ml-1 do not indicate reliably whether the milk comes from healthy udder quarters or contains an admixture of secretion from the diseased quarters. A value of above 500 thousand cellular elements per ml in mixed samples only suggests that the milk probably contains more secretion from infected udder quarters. The number of cells in the mixed samples does not constitute a basis for the conclusion concerning the number of quarters with impaired secretion which contributed to the sample, because the number of cells in the mixed samples depends also on the degree of disease in the respective quarters. An amount up to 500 thousand cellular elements per ml in the mixed sample provides practically no useful and usable information on milk quality. If the number of cellular elements per ml is higher than 500 thousand, this information is only suitable for revealing the stables with a high occurrence of mastitis--it is just a signal, not a parameter of such a situation. It is from this aspect that all results should be evaluated at those places where only mixed samples can be examined.