Serological Investigations of a Bovine Respiratory Disease (“Urner Pneumonie”) Resembling Farmer's Lung

Abstract

The immunological response of cattle exposed to moldy hay was examined by agar gel diffusion with standard farmer's lung hay antigens. A high incidence of precipitins against Micropolyspora faeni (60%) and moldy hay antigen (80%) was detected in exposed but apparently healthy cattle from a region with a high incidence of bovine farmer's lung. In comparison, in the plains, a low incidence area, we found only 1 animal of 164 harboring precipitins against M. faeni. We further observed that many animals from exposed populations lost their precipitins during pasturing and regained them during winter housing. Thirty-nine clinical cases of bovine farmer's lung ("Urner Pneumonie") were investigated serologically. Only 49%, of these animals showed precipitins against M. faeni and 54% showed precipitins against moldy hay antigen. We discuss in this paper the probable causes of this apparent lack of immunological response.

Extracellular enzymes of Micropolyspora faeni found in moldy hay

“…A classical example is the extrinsic allergic alveolitis called farmer's lung, which is observed in man and cattle exposed to moldy hay (14,15,18,22). It is generally accepted that the causative allergens are found in moldy hay and are mostly derived from Micropolyspora faeni, a thermophilic actinomycete.…”