INFLUENCE OF BARN DRYING OF FODDER ON RESPIRATORY SYMPTOMS AND FUNCTION IN DAIRY FARMERS OF THE DOUBS REGION OF FRANCE

Background - A previous study showed there to be fewer microorganisms (especially thermophilic actinomycetes) on farms with artificial barn drying of fodder than on those using traditional storage methods. A cross sectional study was performed to see whether barn drying provides protection against respiratory problems in dairy farmers. Methods - The respiratory symptoms and function of a group of 123 farmers with daily exposure to cattle foddering from farms which had had a barn drying system for at least three years were compared with those of a representative sample of 274 farmers working in farms with traditional storage in five districts in the Doubs region of France. Results - Both groups were comparable for mean age, weight, height, smoking habits, alcohol consumption, past history of respiratory disease, history of allergy, geographical location of the farm, and length of exposure. Retrospectively estimated exposure to fodder was greater in the group using a barn drying system than in the group working with traditional storage. Acute symptoms at exposure (rhinitis, eye irritation, dry cough, asthma symptoms) and chronic symptoms all tended to be less frequent in the barn drying group, although not individually significantly so. Mean (SD) respiratory function parameters were higher in the barn drying group than in the traditional group: % vital capacity (VC) 104 (14) v 102 (15); % forced expiratory volume in one second (FEV(1)) 99 (14) v 94 (18); % FEV(1)/VC 96 (11) v 92 (16); % forced mid expiratory flow (FEF(25-75)) 87 (24) v 79 (25). Conclusion - The results of this cross sectional study suggest that barn drying of fodder may protect respiratory function in dairy farmers.