Antibiotics in Animal Feed

Antibiotics are widely used in animal production systems for the treatment, prevention and control of bacterial infections. In certain production systems, veterinary medicines may be incorporated into feed to allow controlled dosing across groups of animals. Medicated feed therefore plays an important role in maintaining animal health and supporting veterinary treatment programmes.
Because these compounds are biologically active and subject to regulatory oversight, their presence in feed must be carefully controlled. Analytical monitoring is commonly used to confirm that medicated feed contains the intended active ingredients and that non-medicated feed remains free from unintended contamination.

The use of antibiotics in livestock production is closely regulated in many countries due to concerns surrounding antimicrobial resistance and food safety. Monitoring these compounds in feed helps ensure that veterinary medicines are used responsibly and in accordance with regulatory requirements.
Laboratory analysis may be required for several reasons. Feed manufacturers may need to verify that medicated products contain the correct active ingredients at the expected concentrations. Testing may also be used to confirm that cross-contamination has not occurred when medicated and non-medicated feeds are produced on shared manufacturing equipment.
Independent analytical testing therefore provides an important layer of verification for feed producers, veterinarians and regulatory authorities.

Antibiotics Commonly Found in Feed
A range of veterinary antibiotics may be present in feed depending on the livestock species, treatment programme and regulatory environment. These compounds belong to several different chemical families and are used to manage a variety of bacterial diseases affecting livestock.
Examples of antibiotics that may be monitored in feed include:
‣ Amoxycillin
‣ Chlortetracycline (CTC)
‣ Oxytetracycline (OTC)
‣ Doxycycline
‣ Sulphadimidine
‣ Sulphadiazine
‣ Tiamulin
‣ Tylosin
‣ Zinc bacitracin
Some antibiotics, such as tetracyclines and sulphonamides, are commonly used to treat bacterial infections in livestock. Others, including tylosin and tiamulin, are frequently associated with respiratory or intestinal disease control in swine and poultry production. Zinc bacitracin has historically been used in certain feed applications as an antimicrobial growth promoter, although regulatory policies regarding its use differ between regions.
Additional veterinary compounds such as olaquindox or abamectin may also be included in broader monitoring programmes where feed is screened for a wider range of veterinary medicines.