LONGITUDINAL-STUDY OF RESPIRATORY HEALTH IN DAIRY FARMERS - INFLUENCEOF ARTIFICIAL BARN FODDER DRYING

Factors influencing respiratory consequences of dairy farming have not been extensively investigated to date, To evaluate the effects of bar n fodder drying on respiratory symptoms and lung function, a 5 yr foll ow-up study was of performed in the Doubs (France), A cohort of male d airy farmers was analysed in 1990. The initial cross-sectional results suggested that barn-drying fodder may protect dairy farmers from lung function impairment, In 1995, 113 barn-drying farmers (92%) and 231 t raditional-drying farmers (84%) were re-analysed, Barn and traditional fodder-drying farmers were compared for prevalence of symptoms and sp irometric measures of lung function, After controlling for age, smokin g status, altitude and cumulative exposure, barn-drying farmers compar ed to traditional-drying farmers had a lower prevalence of chronic bro nchitis (4 versus 10%; p<0.05) and slightly higher values of forced ex piratory volume in one second (FEV1) (p=0.06) and FEV1/vital capacity (VC) (p<0.01). Nevertheless, decline of the respiratory function param eters was not significantly different between the two groups, Variable s positively and significantly associated to longitudinal decline of l ung function parameters were: age (FEV1, FEV1/VC); altitude (VC, FEV1) and chronic bronchitis and dyspnoea at the initial survey (FEV1/VC), Persistence and emergence of chronic bronchitis dyspnoea and symptoms at exposure were also significantly associated to an acceleration in t he annual decline of the respiratory function, In conclusion, the mode of fodder drying does not seem to significantly influence the decline in lung function, Nevertheless, this study confirms the results of th e initial cross-sectional analysis and supports the hypothesis that ba rn drying fodder may have a protective effect on respiratory health in dairy farming.