Replacement of maize with sweet potato (Ipomoea batatas L.) tuber meal in broiler diets.

1. The nutrient composition of sweet potato tuber meal (SPM) was similar to that of maize, with the exceptions of crude protein and calcium. The crude protein content was lower (62 v 91 g/kg) and the calcium content was higher (l.9 v 0.l g/kg) in SPM. The amino acid composition, in general, favoured SPM. 2. Trypsin inhibitor activity, and the contents of oxalate and phytate-phosphorus in SPM were too low to be of any nutritional concern. 3. The apparent metabolisable energy content of SPM was determined to be similar to that of maize (14.5l V 14.45 MJ/kg). 4. The results of feeding trials showed that SPM can replace up to 400 g/kg maize in broiler diets without adverse effects in performance. The depression in weight gains observed in birds fed on a diet containing 600 g SPM/kg was related largely to lowered food intake arising from the powdery texture of SPM.