Antibiotic Use in European Pig Production: Less Is More

Abstract

The goal of this study is to describe the current use of antibiotics in the European pig industry based on an extensive literature review. To achieve this, an overview of results from national (n = 15) and multi-country (n = 2) cross-sectional and longitudinal (n = 2) surveys, which describe antimicrobial use in pigs, is presented. Results are further linked to the outcome of the European Surveillance of Veterinary Antimicrobial Consumption (ESVAC) project. Overall, it was found that weaned piglets received the most antibiotics, followed by suckling piglets resulting in over 80% of the treatments being administered to animals before 10 weeks of age. Furthermore, it was observed that antibiotic use (ABU) was significantly associated across age categories, indicating that farms with a high use in piglets also used more antibiotics in their finishers. This may, among other things, be explained by farmers' habits and behavior. However, above all, the studies showed surprisingly large differences in ABU between the countries. These differences may be related to the differences in disease prevalence and/or differences in the level of biosecurity. However, they may also reflect variations in rules and regulations between countries and/or a difference in attitude towards ABU of farmers and veterinarians that are not necessarily linked to the true animal health situation. Furthermore, it was observed that already a substantial proportion of the European pig production is able to successfully raise pigs without any group treatments, indicating that it is possible to rear pigs without systematic use of antibiotics. Based on the ESVAC data, a decline of 43.2% was observed in sales of antibiotics for animals in Europe between 2011 and 2020. To enable efficient antimicrobial quantification and stewardship, 15 European countries have already established systems for herd level monitoring ABU in pigs.

Keywords: antibiotic use; antimicrobial use; pigs.

Figure 1

Antimicrobial use in animals in 31 European countries expressed in mg active component/ PCU between 2018 and 2020 (based on eleventh ESVAC report, 2021).

Figure 2

Histogram showing the number of antimicrobial group treatments per week applied to a batch of pigs from birth to slaughter based on 750 treatments (30 instances of treatments missing). The green dotted line represents the weekly average treatment incidence (adapted from Sarrazin et al., 2019) [48].

Figure 3

Country-level comparison of TI per 100 pig-days at risk, based upon group treatment data for a standardized lifespan of 200 days based on defined daily doses for animals (TI200_DDDvet). Every color represents a different European country included in the study (9 countries). Every beam represents a farm (20 farms per country) (adapted from Sarrazin et al., 2019) [48].

Figure 4

Evolution of the median of the BD₁₀₀ *-distribution in the reference populations for 2018, 2019, 2020, and 2021 of each Sanitel-Med pig category. Zero-use farms per year were excluded for the analysis. (BelVetSac 2021) [52]. * BD₁₀₀ stands for “behandeldagen per 100 dagen” which is the Dutch equivalent of the treatment incidence per 100 days at risk.