Effects of removing in-feed antibiotics and zinc oxide on the taxonomy and functionality of the microbiota in post weaning pigs.

Background: Post weaning diarrhoea (PWD) causes piglet morbidity and mortality at weaning and is a major driver for antimicrobial use worldwide. New regulations in the EU limit the use of in-feed antibiotics (Ab) and therapeutic zinc oxide (ZnO) to prevent PWD. New approaches to control PWD are needed, and understanding the role of the microbiota in this context is key.

Fine-tuning of post-weaning pig microbiome structure and functionality by in-feed zinc oxide and antibiotics use.

Introduction: Post-weaning diarrhoea (PWD) is a multifactorial disease that affects piglets after weaning, contributing to productive and economic losses. Its control includes the use of in-feed prophylactic antibiotics and therapeutic zinc oxide (ZnO), treatments that, since 2022, are no longer permitted in the European Union due to spread of antimicrobial resistance genes and pollution of soil with heavy metals. A dysbiosis in the microbiota has been suggested as a potential risk factor of PWD onset.

Metagenomic comparison of the faecal and environmental resistome on Irish commercial pig farms with and without zinc oxide and antimicrobial usage.

Background: Antimicrobials and heavy metals such as zinc oxide (ZnO) have been commonly used on Irish commercial pig farms for a 2-week period post-weaning to help prevent infection. In 2022, the prophylactic use of antimicrobials and ZnO was banned within the European Union due to concerns associated with the emergence of antimicrobial resistance (AMR) and contamination of the environment with heavy metals. In this study, faecal and environmental samples were taken from piglets during the weaning period from ten commercial farms, of which five farms used antimicrobial or ZnO prophylaxis (AB-ZnO farms) and five which had not used antimicrobials or ZnO for the previous 3 years (AB-ZnO free farms).

Antimicrobial Resistance in Commensal of the Porcine Gastrointestinal Tract.

Antimicrobial resistance (AMR) in of animal origin presents a threat to human health. Although animals are not the primary source of human infections, humans may be exposed to AMR of animal origin and their AMR genes through the food chain, direct contact with animals, and via the environment. For this reason, AMR in from food producing animals is included in most national and international AMR monitoring programmes and is the subject of a large body of research.