SUMMARY:One hundred and thirty‐three samples of rumen contents were obtained from four fistulated cows receiving various diets. From dilution counts of all the samples 81 strains of streptococci were isolated, the average of 133 streptococcal counts being more than 108organisms/ml. Much higher counts (109‐1011/ml) were obtained when the cows were receiving grass, whereas the numbers of presumptive lactobacilli in the rumen were low; the reverse applied with concentrate diets, and a reciprocal numerical relationship between streptococci and lactobacilli according to diet is suggested. All the strains of rumen streptococci were identified physiologically asStreptococcus bovisand classified in serological group D by precipitin tests. Agglutination tests with type sera prepared against some of the strains showed the existence of two types ofStrep. bovis, one sharing a common type antigen with streptococci of grou
展开▼
