Influences of somatic cell count on milk composition and dairy farm profitability

The objective of this paper was to investigate seasonal variations in bulk somatic cell totals and milk composition, evaluate the influence of somatic cell count (SCC) on milk fat and protein content and determine the effects of SCC on dairy farm profitability. A total of 1440 samples were analysed. Data were obtained by randomly collecting five samples of bulk tank milk from each of 24 dairy farms every month from April 2008 to March 2009. Milk was analysed for titratable protein, fat content and SCC (direct microscopic cell count). The highest total bulk SCCs were observed during autumn and winter. Conversely, higher levels of milk fat and protein were generated during spring and summer. A significant negative correlation was noted between SCC and milk composition, daily milk yield and milk returns. By logarithmic function, a significant negative relationship was observed between SCC and milk composition or milk returns. In conclusion, this study demonstrates that the SCC is a useful tool for judging dairy farm profit and milk quality.