Acta Scientiarum Polonorum Technologia Alimentaria

Background. The quality of dairy products, raw milk in particular, depends on many factors. Low bacterial and somatic cell counts are basic determinants of the appropriate raw milk quality. The objective of the work was to assess the effect of selected factors, that is, the age of cows and their daily milk performance, on cytological quality (somatic cell count) and energy value of milk produced at individual stages of lactation.
Material and methods. Somatic cell count and energy value of cow’s milk were assessed. A total of 229 792 milk samples were examined. Data for analysis were taken from milk records of 350 dairy herds
Results. It was demonstrated that, of all the lactations studied, the fi rst lactation (from calving to the 100th day of lactation) was characterised by the highest daily milk performance (25.1 kg) and the lowest somatic cell count (356 thous./1 ml), fat, protein and dry matter contents (4.06, 2.96 and 12.41%, respectively) and milk calorifi c value (732 kcal/kg). The highest energy value was recorded in cow’s milk produced towards
the end of lactation, that is from day 300 till the end of lactation (842 kcal/kg).
Conclusions. High milk calorifi c value in late lactation and high fat and protein contents were accompanied by low raw milk quality.