BPEX Pig Health Scheme: a useful monitoring system for respiratory disease control in pig farms?

BPHS reports were obtained from a subset of 70 pig farms involved in a cross-sectional study conducted in 2008-09 investigating the epidemiology of post-weaning multi-systemic wasting syndrome. The reports were combined with data regarding the presence/absence of several pathogens in the herd and potential farm-level risk factors for respiratory disease. Principal component analysis (PCA) performed on BPHS reports generated three principal components, explaining 71% of the total variance. Enzootic pneumonia score, severe pleurisy and acute pleuropneumonia had the highest loadings for the principal component which explained the largest percentage of the total variance (35%) (BPHS component 1), it was thought that this component identifies farms with acute disease. Using the factor loadings a score for each farm for BPHS component 1 was obtained. As farms' score for BPHS component 1 increased, average carcass weight at slaughter decreased. In addition, farms positive for H1N2 and porcine reproductive and respiratory disease virus (PRRSV) were more likely to have higher levels of severe and mild pleurisy reported by the BPHS, respectively.The study found statistical associations between levels of pleurisy recorded by BPHS at slaughter and the presence H1N2 and PRRSV in the herd. There is also some evidence that farms which submit pigs with these lesions may have reduced productivity. However, more research is needed to fully validate the scheme.Respiratory diseases are a major problem in intensive pig farming [1] accounting for significant economic losses due to increased mortality, morbidity and treatment costs and reduced growth rates, feed conversion efficiency and carcass quality [2,3]. Enzootic pneumonia and pleuritis (or pleurisy) are common respiratory diseases in the UK pig industry, lesions indicative of which are frequently found in pig lungs at slaughter [4-6].Slaughter data has been used in epidemiological studies [4,7-9] and several infectious and non-infe