Evaluation of effects of the dry-heat-processed sweet potato waste as broiler feed

This study was conducted to examine the effects of feeding dry-processed sweet potato waste on the growth of broilers. Sweet potato waste was air-dried (A-SPW) or heat-dried (D-SPW). Twenty-four 14-d-old chicks were assigned to the following groups (14-28 days): control, fed a corn-soybean meal-based diet; A-SPW, fed the basal diet with 55% of the corn replaced with A-SPW meal; D-SPW, fed the basal diet with 50% of the corn replaced with D-SPW meal. The feed conversion ratio (feed/gain) of the D-SPW group was greater than that of the A-SPW group. The relative weight of abdominal fat and the muscle lipid content of the D-SPW group were increased compared with those of the A-SPW group. The metabolizabilities of crude protein and gross energy of the D-SPW group were increased compared with those of the A-SPW group. The plasma alpha-tocopherol concentrations of the A-SPW and D-SPW groups were greater than that of the control group. Plasma malondialdehyde was decreased in the A-SPW and D-SPW groups, and muscle malondialdehyde was decreased in the D-SPW group, compared with the control group. Our results demonstrate that dry-heat processing improves the nutrient metabolizability of sweet potato waste and makes it into available feed for broilers.