Detection of antibiotic residues in calf tissues.

Groups of calves were injected with penicillin, ampicillin or oxytetracycline and a variety of samples were taken from the calves when slaughtered and tested for the presence of antibiotic residues by microbiological assay. Diaphragm and urine samples were found to be suitable for measuring detectable levels of antibiotics in calves given therapeutic injections.