EN
The investigation of relationships between collection system, season and monthly delivery size and somatic cell count in 1 ml of milk classified to the highest quality classes (Extra and the First) in one of leading dairy co-operatives from the region of Central Poland was the aim of the study. Somatic cell count (SCC) of individual milk supplies constituted the research material. Results confirmed that milk collected directly from the farm by autocysternes had much lower SCC level. The increase of the average monthly milk supply had positive relationship with its hygienic quality. The worst milk quality was noticed in the summer season, i.e. in June, July and August, regardless of delivery system. The results show further possibilities of improvement of hygienic conditions of milk production and collection in Poland.