The purpose of this chapter is to review the methods for detection of antibiotic residues in animal feed, using the example of distillers’ grains. There is a growing concern about the use of antibiotics in the process of which distillers’ grains are a co-product. Antibiotic residues in distillers’ grains may contribute towards antimicrobial resistance in animals and humans. This chapter reviews the use of distillers’ grains as animal feed and provides an overview of multiresidue methods for analysing residues in feed, with particular attention to ion-trap tandem mass spectrometry and orbitrap high-resolution mass spectrometry. It also discusses the extent to which antibiotic residues have been found to survive in feed, and considers how the risk of antimicrobial resistance can be assessed