EN
The investigations were carried out on 414 cows from one farm. The cows were evaluated twice before the end of lactation by clinical examination of udders and laboratory examination of milk samples. Antibiotic solutions (197 cows) or DC preparations (177 cows) were infused into all quarters after last milking. Groups of cows were treated with antibioties in combination with chlormethine or levamisol. It was found that after calving in control group (40 cows) there were more cows with infected quarters than before drying off. The results of treatment varied. Combinations of procainic penicillin (600 000 im) with streptomycine (0,5 g) gave better results than these antibiotics at 50% lower doses. Treatment with DC and Ilcocillin DC was more effective than the use of antibiotic solutions. Therapeutic and prophylactic effectiveness of antibiotics in dry cows increased after their supplementation with chlormethine.