Association of the M blood group system with bovine mastitis.

Associations of the 11 bovine blood group systems with mastitis were examined in Red Danish dairy cattle. The mastitis status was followed during three lactational periods. A significant effect of the M blood group system on mastitis incidence was observed in the first and second lactation periods and a lower frequency of mastitis is found among animals lacking the M' factor as compared to those having the M' blood group factor.

Herd incidence of bovine mastitis in four danish dairy districts. III. Relation between frequency of mastitis and cell counts on bulk molk samples.

The correlations between monthly bulk milk cell counts and the actual frequency of mastitis was investigated in 399 Danish dairy farms with a total of about 7000 cows. The correlation coefficients varied from 0.3 to 0.

Herd incidence of bovine mastitis in four Danish dairy. districts II. Evaluation of the effect of the mastitis control scheme.

Bacteriological and cytological examinations have been carried out on samples from 6,808 cows belonging to 339 herds in four Danish dairy districts. After a discussion of differences between the districts as regards intensivity of mastitis control, public health surveillance, etc., definitions are given of certain terms, such as presence of bacteria, infection, pathogenic versus non-pathogenic (less pathogenic) organisms.