EN
In 1983—1988 was introduced a program of mastitis control in about 20 000 cows in 120 herds in cooperatives at the Gdańsk voivodeship. The program was realized by 4 laboratory and field units directed by the Center of Veterinary Hygiene. The following changes of the examined parameters during one year period of mastitis control, when the value at 1983 was assumed as 100%, were noted: increase by 8.81% of cows with healthy udders at milk yield increased by 4.2%. Decreased a total number of cows by 3.95%, clinical forms of mastitis by 6.4%, subclinical forms of mastitis by 12,2%, aseptie forms of mastitis by 17.6%. Yield milk in 1983 was 3051, in 1988 3769 1, and yield milk increased by 145.71.