A high number of antimicrobial-resistant genes have been found in pig faeces at a commcerical farm in a Scotland’s Rural College (SRUC) study.

The research was carried out during a single production cycle on a commercial pig unit with a high antimicrobial usage.

The study found antimicrobial-resistant (AMR) gene counts were high but relatively stable over time, suggesting the genes had become integrated into the faecal microbial community.

However, the resistance was not high enough to prevent the use of antimicrobials being given to pigs still working on the farm.

A total of 144 different resistant genes were identified on the farm, with individual genes present in the tens, hundreds and thousands of millions per gram of pig faeces.

Professor Michael Hutchings, head of animal and veterinary sciences at SRUC, said: “At the start of the study, we hoped to find two or three genes to follow their numbers through the pig production cycle. The richness of AMR genes and their numbers were unexpected.”

The study was funded by the Natural Environment Research Council and the Scottish Government with the work conducted by SRUC in partnership with the University of Edinburgh’s Roslin Institute.