Using enterprise gross output as an argument for endemic disease control at farm level.

A longitudinal study was used to investigate the utility of enterprise gross output analysis for disease impact assessment and provision of performance indicators to enable informed decisions on endemic disease control at the farm level. Empirical information available through the British national cattle tracing system was used to calculate five consecutive annual enterprise gross outputs for 22 beef enterprises. The economic information was then linked to bovine viral diarrhoea herd status. This approach allowed assessment of disease mortality and reduced fertility on performance within farms and benchmarking between farms. Furthermore, it can be adapted to include information on individual livestock weights thus enabling assessment of morbidity on performance. Contracting active infection with bovine viral diarrhoea virus was associated with reductions in enterprise gross output ranging from 3% to 35%. For farms with prolonged infection, production risk increased as measured by greater variation in enterprise gross output