Trace metal feeding on dairy gut microbiome and resistome

Dietary trace mineral (TM) concentrations for lactating cows often exceed national recommendations. However, the presence of certain TM can exert selection pressure on the gut microbiota, promoting metal resistance and potentially co-selecting for important antimicrobial resistance genes (ARGs). This study used a cross-over design to investigate whether over-supplementation of three TMs, cobalt, manganese and zinc, alters the gut microbiome and resistome of dairy cattle. The findings highlighted the resilience of the dairy cow gut microbiome and resistome to short-term surplus TM feeding, warranting further research into long-term effects.