Cell count in milk
The majority of the cells contained in the milk are leukocytes (white blood cells). If the animals are infected by pathogenic bacteria and suffer from a mastitis, the body responds with a stronger immune reaction, which increases the number of leukocytes rapidly.
An increase in the number of cells in the milk always means a reduction in performance. Already cell numbers that are more than 200 000, indicate a lack of udder health. At the latest in cell numbers of 400 000 cells per milliliter, I can expect a performance reduction of at least 10%.
(Sources: Lexicon of Milk 1988, Prof. Dr. Edmund Renner; State Association of the dairy Industry Nordrhein-Westfalen e.v.; Regulation on the quality assessment and payment of the delivery milk)