Risk Factors for Antimicrobial Use on Irish Pig Farms

Abstract

The threat to public health posed by antimicrobial resistance in livestock production means that the pig sector is a particular focus for efforts to reduce antimicrobial use (AMU). This study sought to investigate the risk factors for AMU in Irish pig production. Antimicrobial use data were collected from 52 farrow-to-finish farms. The risk factors investigated were farm characteristics and performance, biosecurity practices, prevalence of pluck lesions at slaughter and serological status for four common respiratory pathogens and vaccination and prophylactic AMU practices. Linear regression models were used for quantitative AMU analysis and risk factors for specific AMU practices were investigated using logistic regression. Farms that milled their own feed had lower total AMU (p < 0.001), whereas higher finisher mortality (p = 0.043) and vaccinating for swine influenza (p < 0.001) increased AMU. Farms with higher prevalence of pericarditis (p = 0.037) and lung abscesses (p = 0.046) used more group treatments. Farms with higher prevalence of liver milk spot lesions (p = 0.018) and farms practising prophylactic AMU in piglets (p = 0.03) had higher numbers of individual treatments. Farms practising prophylactic AMU in piglets (p = 0.002) or sows (p = 0.062) had higher use of cephalosporins and fluoroquinolones. This study identified prophylactic use and respiratory disease as the main drivers for AMU in Irish pig production. These findings highlight areas of farm management where interventions may aid in reducing AMU on Irish pig farms.

An Integrated Analysis of Abattoir Lung Lesion Scores and Antimicrobial Use in Italian Heavy Pig Finishing Farms

“…Herd-level antimicrobial prescription data from Danish organic pig herds were analyzed for associations with abattoir meat inspection findings, but no significant results emerged [ 27 ]. In another study, no direct association was observed between the total AMU on Irish farrow-to-finish pig farms and the prevalence of pneumonia and pleurisy at slaughter, but positive associations were found with the prevalence of pericarditis, lung abscesses and liver milk spots [ 8 ]. In the present study, although the EP score did not vary with the total AMU, it was positively associated with the usage of macrolides and critical classes.…”

“…The evaluation of respiratory tract lesions is also of great interest, as the porcine respiratory disease complex (PRDC) represents a major economical, health and welfare problem in pig production worldwide [ 7 ]. Furthermore, PRDC is one of the main drivers of antimicrobial use (AMU) in pig farming [ 8 ]. The most prevalent lung lesions in slaughtered pigs are cranioventral pulmonary consolidation (CVPC) and chronic pleuritis, as reported in several studies [ 9 , 10 , 11 ].…”

“…Thus far, the relationship between lesions found at slaughter and AMU in pig pro-duction has rarely been investigated [ 8 , 27 , 35 ]. Further research in this field could shed light on whether and how information from abattoir lesion assessments can be used to improve antimicrobial stewardship, with the objective to reduce and rationalize AMU.…”