Sulfamethazine residues in swine

Area of Science:

• Veterinary Pharmacology
• Food Safety
• Animal Science

Background:

• Sulfonamides, including sulfamethazine, are used in swine production.
• Violative residues in animal products pose risks to human health and trade.
• Understanding drug accumulation and elimination is crucial for withdrawal protocols.

Purpose of the Study:

• To investigate the causes of violative sulfonamide residues in swine.
• To compare plasma sulfamethazine disappearance rates after single oral dose versus continuous feeding.
• To determine tissue accumulation levels at different dietary sulfamethazine concentrations.

Main Methods:

• Comparison of plasma sulfamethazine disappearance kinetics.
• Administration of sulfamethazine in feed at 2 µg/gm and 8 µg/gm.
• Analysis of sulfamethazine residues in swine tissues (liver, kidney, muscle) post-slaughter.

Main Results:

• No significant difference in plasma sulfamethazine disappearance rates between single oral dose and continuous feeding.
• Violative sulfamethazine residues were found in the liver of swine fed 2 µg/gm for 7 days.
• Violative concentrations were detected in liver, kidney, and muscle tissues of swine fed 8 µg/gm.

Conclusions:

• Continuous feeding of sulfamethazine-containing feed can lead to violative tissue residues in swine.
• Even low concentrations (2 µg/gm) in feed can result in violative liver residues.
• Withdrawal periods must consider dietary drug levels to prevent violative residues in meat products.