Relationship between Mastitis Agents and Somatic Cell Count in Foremilk Samples

The purpose of the study was to determine the microorganism species dependently on somatic cell count (SCC) in foremilk (inflammatory secretion) samples. Bacteriological examinations of 18 713 samples taken from clinically and subclinically (CMT positive) inflamed quarters were performed according to standard methods. Above 13% of the samples originated from quarters previously treated with antibiotics, and 75% of them were free from infection. Milk samples with SCC lower than 200 000 were mostly (59.6%) culture negative. Coagulase-negative staphylococci (CNS), Staph. aureus and Streptococcus sp. were mostly noted in samples with 200 000-2 000 000 of SCC/ml. Samples having more than 2 million/ml of SCC were infected mainly with CAMP-negative and CAMP-positive streptococci and Gramnegative bacilli. The highest SCC (≥10 mln/ml) in foremilk samples were associated with intramammary infections by Arcanobacterium pyogenes (95.5%), Streptococcus agalactiae (57.6%) and Gram-negative organisms (46.5%). Very high SCC (≥5mln/ml) was connected with infections caused by Prototheca sp. (64.5%), Yeast-like fungi (60.2%) and Streptococcus sp. (55.1%). Staph. aureus (76.2%), CNS (84.2%), Gram-positive bacilli (72.4%) and Corynebacterium sp. (83.2%) caused an increase in SCC that was smaller than 5 mln/ml.