Cilj istraživanja bio je ustvrditi korelaciju između proizvedene količine mlijeka i kemijskog sastava mlijeka te omjera mliječne masti i bjelančevina krava holštajnske pasmine. Istraživanje je provedeno na kravama holštajnske pasmine u starosti od 2 do 5 godina. Krave su raspoređene u tri skupine prema dnevnoj prosječnoj količini proizvedenog mlijeka (DKM): skupina A krave < 15 kg DKM (n = 8), skupina B 15 – 25 kg DKM (n = 8) i skupina C ≥ 25 kg DKM (n = 8). Istraživani parametri bili su mliječna mast, bjelančevine, laktoza i ureja te broj somatskih stanica. Statistički značajni parametri (P < 0,05) bili su udio bjelančevina (%) i mliječne masti (%) između triju istraživanih skupina životinja, ukupna količina mlijeka u 305 dana laktacije i prosječna dnevna količina mlijeka. Ovim istraživanjem zaključeno je da što je veća proizvodnja mlijeka u 305 dana laktacije, kao i prosječna dnevna količina mlijeka, to su postotak mliječne masti i bjelančevina u ukupnom sastavu mlijeka manji.The aim of the study was to determine any correlation between milk quantity and the chemical composition of milk and milk fat to protein ratio of Holstein breed cows. The study was conducted on cows of the Holstein breed at the age of 2-5 years. The cows were divided into three groups according to the daily average amount of milk produced (DAM): group A cows <15 kg DAM (n=8), group B 15-25 kg DAM (n=8) and group C ≥25 kg DAM (n=8). The parameters investigated were: milk fat, proteins, lactose and urea, and the number of somatic cells. The statistically significant parameters between the investigated three animal groups (P<0.05) were protein content (%) and milk fats (%), the total amount of milk in 305 days of lactation, and the average daily amount of milk. It was concluded that the higher the milk production over 305 days of lactation, in terms of the average daily amount of milk, the lower the percentage of milk fat and protein in the total milk composition
