Feed preparation and pharmacokinetics of chlortetracycline in piglets

18 piglets were fed either a dry, humid or soup diet and each animal was dosed with 40 mg chlortetracycline/kg bodyweight. The chlortetracycline-concentration in the diet was 2500 mg/kg air-dried feed. After a single oral dosage the absorption of chlortetracycline occurred significantly faster from the soup diet, resulting in higher serum levels as well as prolonged elevated serum concentrations of CTC compared with the other two diets. Using a mathematical model, serum concentrations over a 5-day period with repeated dosage of CTC were calculated. Based on this dates we recommend the following dosage regime for chlortetracycline: 20-30 mg CTC/kg bodyweight/12 h for soup feeding and 30-40 mg CTC/kg bodyweight/12 h for dry or humid feeding.