Description: Measuring the welfare of cows on farms was carried out according to the protocol of Welfare Quality scoring system. On farms with lower level of welfare as well as the poorer implementation of principles of good nutrition, significantly lower milk production was found, as well as a greater percentage of cows with a long service period, lameness and a higher percentage of very thin cows. Providing good accommodation principles will significantly improve milk production, reduce the number of cows with a long service period as well as the ones with lameness, and it is particularly interesting that obliging this principle will provide less subclinical mastitis on a farm and less cows with dystocia and skin lesions. The most important principle, which has demonstrated a significant effect on the values of all parameters, is the principle of good health