Correlations Between Somatic Cells Count and Milk Composition with Regard to the Season

Abstract

SUMMARY On four farms with 1100 cows of Black-and-White breed the correlations between somatic cell count (SCC) in milk and milk composition in different seasons of the year were studied. Three-year data from AP milk recording were analysed (years 2000 to 2002), which meant 29,298 samples of milk. Milk fat, proteins and lactose were determined using Milco-Scan while somatic cells were determined with Fossomatic 90. The three-year average content of fat was 4.16 % (CV=18.75 %), 3.41 % (CV=12.02 %) of proteins, and 4.58 % (CV=5.68 %) of lactose. SCC averaged to 499.2 x 10 3 / ml milk. The threeyear average showed a statistically significant (p≤ 0.0001) positive correlation between LSCC and fat content (0.130) and protein content (0.240), and a statistically highly significant negative correlation between LSCC and lactose content (-0.423) and daily milk production (-0.286). In special seasons of the year the correlations for fat (0.177), proteins (0.287) and amount of milk (0.327) were the highest in spring, while (-0.461) in autumn for lactose; all of them were statistically highly significant. The milk composition was in a statistically highly significant correlation with SCC in milk and year season.