Impact de l'utilisation du lait contenant des résidus d'antibiotique dans l'alimentation lactée du veau

Abstract

Aim of this work : The aim of the study is to investigate calves management practices in Wallonia and to estimate the risks of antimicrobial resistance related to those practices. The second part, more experimental, assesses the relationship between the consumption of waste milk with antimicrobials residus and the development of antimicrobial resistance among calves. Summary : Due to antimicrobial resistance management, it is mandatory to remove from the market any milk containing antimicrobial residues. In order to valorize the waste milk, some farmers choose to feed their calves with it. This practice is still common in Europe and around the world. However, the antimicrobial resistance development risk, can make such a practice debatable. The survey realised among the walloons cattle farmers, revealed a common but still moderate practice to feed calves with waste milk. Moreover, among farmers beta-lactams remain widely used including one critical family: last generations cephalosporins along with colistin, another critical antibiotic. Finally, this survey does not highlight major differences of calves management practices when compared to different countries. The experimental part doesn’t bring a significant correlation between the consumption of waste milk and an antimicrobial resistance increase among calves bacterial flora. Only the age seems to be a protective factor of finding critically important antimicrobials resistant germs . A large number of multiresistant Escherichia coli have been detected during this experience. Moreover, two particularly pathogenic strains CS31A et ATT F17a have been regularly found for any feeding sources. Only the Enterohemorragic strains have only been associated with the consumption of waste milk. Those three strains were more likely to be multiresistant when compared to non-typable ones