Effect of oxytetracycline supplementation on nutrient digestibility in veal calves

The hypothesis tested was that the antibiotic oxytetracycline stimulates fat digestion in veal calves fed a milk replacer containing soy protein concentrate. It was reasoned that the carbohydrates in soy protein concentrate stimulate bacterial growth in the small intestine, leading to deconjugation of bile acids, which in turn inhibits fat digestion. From week 19 to 23 of the experiment, the milk replacer either contained oxytetracycline (80 mg/kg in the powder) or not. Bodyweight gain and feed intake were not influenced by oxytetracycline. Moreover, supplemental oxytetracycline affected neither bile acid excretion in feces or apparent fat digestion. Oxytetracycline increased (P < 0.05) the apparent absorption of magnesium.