Digestibility and utilization of faba bean (Vicia faba L.) diets in broilers

Abstract

There is a strong interest in maximizing the use of locally produced protein sources, like faba beans (FB), as a substitute for imported soybean meal (SBM). The aim of the present study was to determine the effects of dietary FB inclusion on diet digestibility. A further aim was to find an optimal inclusion level of locally produced unprocessed FB seeds in diets of broilers. A total of 196 male Ross 508 chicks were randomly assigned to four feeding treatments, and seven replications per treatment. FB seeds in proportions of 0, 80, 160, and 240 g/kg in the wheat- and SBM-based diets were tested in the grower period (bird age of 6–32 days). Digestibility and retention of nutrients were determined at the end of the experiment, and production performance was measured throughout the experiment. Apparent total tract digestibility of ash, nitrogen retention, apparent ileal digestibility of organic matter, and the nitrogen-corrected apparent metabolizable energy increased, with increased FB inclusion. The apparent ileal digestibilities of alanine, arginine, aspartic acid, histidine, and treonine increased by FB inclusion, while the apparent ileal digestibilities of cysteine and proline decreased. Digestibility differences were related to FB inclusion, but as well changes in proportion of wheat and SBM. Body weight, body weight gain, and feed consumption linearly decreased when dietary FB inclusion increased, while feed conversion ratio linearly improved. FB inclusion had no negative effect on the health of the broilers. In conclusion, 160 g/kg of FB can be used in broiler diets without major negative effects on production performance.