What specific source contributes to the presence of veterinary drug residues categorized as chemical contaminants in animal feed?

Traces remaining if the animal consuming the feed was previously treated with medication

Veterinary drug residues fall under the category of chemical contaminants monitored in animal feed. The primary source of these residues is the medication administered to the animals for whom the feed is ultimately intended. If an animal received treatment, trace amounts of that chemical might persist in the feed components designated for that animal. Since regulatory standards for animal feed differ from those for human food, these trace residues may be present at levels deemed acceptable for livestock but potentially unsafe for consistent human consumption.