Effect of somatic cell counts in milk on its quality depending on cow breed and season

The aim of the present work was to determine the physicochemical quality of milk in relation to the bovine udder health status, taking cows' breed and production season into consideration. The studies were conducted throughout three successive years (2006-2008) on milk samples collected from the cows of three breeds, i.e. Polish Holstein-Friesian Black and Red-White variety, Simental and Jersey. All cows were managed in free-stall barns and their feeding system, in winter as well in summer season, was based on TMR (total mixed ratio). A total of 1822 milk samples were researched. In each sample the somatic cell count (SCC), chemical composition as well as acidity were examined. The research material within each breed was assigned into four groups according to SCC. It was found that the increase of SCC in milk first of all led to a decrease of casein share in crude protein and lactose content, with a slight decrease in fat content. It should be marked that the statistically significant changes in some milk components content were noted only when SCC exceeded 500 000 cells cm-3, so in the milk which does not meet the current quality requirements.