Somatic cells count in milk - indicator of milk quality and health of cows

Absztrakt

In years 2000 and 2001 on 4 farms with total number of 1100 cows of the Friesian breed and annual production of approx. 8 thousand tons of market milk in defined region the influence of farm and management factors, year season and studied years on the somatic cells count in stable (tank bulk) milk samples (SCCss) and samples of milk of individual cows (SCCis) was analysed. There were calculated the correlations between the somatic cells count and the number of treated cases of mastitis, between somatic cells and milk quantity and between milk quantity and the number of treated cases of mastitis. In the studied years there was on average SCCss (n=271) 328.2x103/ml of milk (LSCCss is 5.51 ±0.08/ml), and on average SCCis (n=21942) 448.8x103/ml of milk (LSCCis is 5.24/ml). On SCCss of milk there was statistically highly significant influence of years (F=41.76, P ≤0.0001), farm (F=25.44, P≤0.0001), and not of the season (F=0.36, P=0.547). On SCCis of milk there was, however, statistically highly significant (P≤ 0.0001) influence of all three factors, i.e. years (F=904.19), season (F=47.92) and farm (F=20.94). Year and season had no statistically significant influence on manifestation of mastitis (F-0.30, P=0.587 and F=0.91, P=0.344), while statistically highly significant was the influence of the farm (F=26.81, P≤0.0001). Between SCCis of milk and number of treated cases of mastitis there is statistically significant correlation (r=0.275, P ≤0.008), between number of cases of mastitis and milk quantity the correlation is r=0.332, P≤0.001, and between milk quantity and SCCss the correlation is r=-0.289, P≤0.006. The correlation between SCCss of milk and SCCis of milk (r=0.608, P≤0.0001) is statistically highly significant.