Some factors influencing milk somatic cell count of Holstein Friesian and Brown Swiss cows under the Mediterranean climatic conditions

Abstract. The aim of this study was to determine the influencing factors on somatic cell count (SCC) in the milk of Holstein Friesian (HF) and Brown Swiss (BS) cows raised on three dairy farms under the Mediterranean climatic conditions in Turkey. For a two-year period, farms were visited monthly to measure daily milk yield (DMY) and collect milk samples from each cow during the morning and evening milking. Total of 1 429 SCC readings from 67 HF and 16 BS cows were analyzed by using repeated measures. Breed (P<0.01), lactation number (LN) (P<0.01), milking time (MT) (P<0.05), lactation month (LM) (P<0.01) and the interactions of breed-LM (P<0.05), herd-LM (P<0.01) and LN-LM (P<0.01) effects on SCC were statistically significant as did the co-variable DMY effect (P<0.01). The effect of herd and herd-MT interactions on SCC were statistically insignificant (P>0.05). The SCC means for BS and HF cows were 5.464±0.060 (291 072 cells/ml) and 5.654±0.029 (450 817 cells/ml), respectively. The SCC mean for morning milking (338 065 cells/ml) was 25 850 cells/ml lower than that of evening milking. The LN4 had the highest SCC mean (490 908 cells/ml) and was statistically different from those of LN1 (P<0.01) and LN2 (P<0.05). The SCC level was the highest in the first LM (601 174 cells/ml) and this level then decreased in the later months. Possible reasons for the difference in SCC means between the breeds are different resistance mechanisms against mastitis, different morphological conformations of udders and different milk yields between these two breeds. The insignificant differences found among herds show the similarities of management, milking hygiene and barn conditions. In order to decrease SCC in milk and increase udder health, some precautions need to be taken like improving milking management, hygiene and barn conditions, milking the cow at uniform intervals, feeding the cows after the milking and applying a mastitis control program.