Effect of "geopathic" radiation emitted by water underflows was evaluated in a cow-shed localized in Zulawy region. On a ten-degree scale, the teams of dowsers identified 4 zones of underflow activity, including 3 extremely harmful areas: 10, 9 and 5 deg, and control zone of 1 deg. Milk yields, fat production and herd replacement were analysed. The lowest milk and fat yields were obtained from cows staying on stands subjected to 10 and 9 deg radiation; the highest - at 1 deg radiation. The highest herd replacement rate was recorded for cows receiving 10 and 9 deg radiation. Cows were removed from the herd due to infertility, leukaemia, miscarriages, post-calving palsy, circulatory failure and low milk yield