Modeling antimicrobial fate in the circular food system

Abstract

The livestock sector plays a critical role in the circular food production system, but excessive use of antimicrobials (AMs) in livestock farming can lead to AM residue contamination in human food. CirFSafe, a model framework was developed to predict the fate of five different AMs in a primary circular food production system, comprising mixed farms with arable (maize) and animal (bovine) components. Two bovine exposure scenarios to AMs were simulated: annual constant exposure and a one-off exposure in the first year of circularity. Over a 5-year timeframe, model predictions suggest that fertilizing soil with animal manure and feeding animals with maize grown in the same soil are unlikely to cause AM residues in milk or meat exceeding European regulatory limits. Nevertheless, the distinct residual patterns of different AMs across the system underscore the need for precautionary monitoring, particularly for the routine use of flumequine (FLU) and doxycycline (DOX), which exhibits a greater tendency to transfer into food products.