Modeling antimicrobial fate in the circular food system

Area of Science:

• Food safety and sustainable agriculture
• Environmental science and risk assessment
• Veterinary pharmacology and toxicology

Background:

• Antimicrobial (AM) use in livestock can lead to residues in food, impacting human health.
• Circular food production systems integrate crop and animal farming, raising questions about AM fate.
• Understanding AM transfer in these integrated systems is crucial for food safety.

Purpose of the Study:

• To develop and apply the CirFSafe model framework for predicting the environmental fate of five AMs.
• To assess AM residue levels in food products (milk, meat) from a mixed crop-livestock farm.
• To evaluate two distinct AM exposure scenarios in bovine populations within a 5-year circular system.

Main Methods:

• Simulation of five different antimicrobials (AMs) within a circular food production model (CirFSafe).
• Modeling a mixed farm system with arable (maize) and animal (bovine) components.
• Simulating two bovine AM exposure scenarios: annual constant exposure and one-off initial exposure.

Main Results:

• Model predictions indicate AM residues in milk and meat are unlikely to exceed European regulatory limits under simulated conditions.
• Fertilizing soil with manure and subsequent maize cultivation did not lead to significant AM transfer to food products.
• Distinct residual patterns were observed for different AMs, with flumequine (FLU) and doxycycline (DOX) showing higher transfer potential.

Conclusions:

• Circular farming practices, as modeled, appear to minimize AM residue risks in food products below regulatory thresholds.
• Precautionary monitoring is recommended due to varying AM behaviors, especially for flumequine and doxycycline.
• The CirFSafe model provides a valuable tool for assessing AM risks in integrated agricultural systems.