Cell volume to aid analysis and technique of somatic cell counts in milk.

In conjunction with a Coulter Counter, somatic cells in milk were sized by electronic analysis. Quarter milk from cows with mastitis had a cell volume peak with a modal cell volume of 102 mu3 while milk from healthy quarters had no peak. Bulk milks with a peak had higher cell counts than milks where there was no peak. Dimensions of peak from bulk milks were the same as from quarter milks. Modal cell volume and cell count varied after milks were fixed with varying concentrations and types of fixative. The concentration of fixative recommended by the International Dairy Federation was sufficient, but only marginally so, and it should be increased.