Pathogenesis of subclinical bovine mastitis: persistence, deterioration and improvement of various subclinical conditions monitored by means of the International Dairy Federation/Bovine Serum Albumin criteria.

From this investigation, it is apparent that owing to the superior diagnostic differentiating of udder conditions by means of the IDF/BSA criteria, a range of detailed data has become available which facilitates an unprecedented insight in the dynamic balancing during normal lactation of several health states determinable at subclinical levels. The findings therefore from different points of view augment the corresponding results generated during the preceding investigation by means of the IDF criteria of acknowledged diagnostic limitations. In general, the data suggests that regardless of the diagnostic technique used for determinations during normal lactation on bovine udder conditions, udder health as such depends on 3 major determinants, namely intramammary epithelial integrity, intramammary somatic cellular defence and intramammary bacterial challenge. Subclinical septic mastitis, clearly, develops through different types of gradually escalating deteriorations of health states which depend on several pathways of pathogenetic development. These are subject on the one hand to the 3 major determinants of udder health, and on the other hand to the nature and magnitude of their single and combined challenging. The deterioration of udder health in some quarters is opposed by the improvement of that in others which in the light of data on the rather transient persistence of health states implies, that deterioration of condition is at all levels of its development opposed directly but, possibly, somewhat delayed by the cow's efforts at restoring udder health as such to its completely normal level.(ABSTRACT TRUNCATED AT 250 WORDS)