Somatic Cell Content Variation in Fraction-Collected Milk

Total milk somatic cell content of various fractions of milk collected during milking were estimated by reflectance Feulgen-DNA, to determine which portion provided the best estimate of the number of somatic cells in primary milk, and to attempt to better understand the cellular variation in various fractions of milk. The first five fractions did not differ significantly (P ~ 0.05) from primary milk, but strippings and complementary milk each contained significantly (P < 0.0]) more somatic cells than primary milk. Correlations between total somatic cell content in each fraction with the total somatic cell content in primary milk ranged from 0.91 to 0.97. The data indicared that any of the fractions used in this experiment could be used to predict the number of somatic, cells in primary milk.