Somatic cells – causes and consequences of their varying presence in cow milk

Abstract This study analyses key aspects of somatic cells in cow milk. It outlines their types, physiological levels, and diagnostic value for udder health, particularly in detecting subclinical mastitis. Methods for determining somatic cell counts are presented, with bacterial infections identified as the main cause of elevated levels. The role of lactose concentration as a practical indicator is highlighted, alongside environmental and genetic factors influencing somatic cell variation in breeding practice. The consequences of high counts – such as reduced milk yield, lower processing quality, and diminished reproductive performance – are summarized. Finally, the study discusses hygiene prophylaxis measures and the role of somatic cell monitoring in dairy cattle improvement programs worldwide.