Effect of air-classified faba bean protein on feed production, physical pellet quality, performance, and protein digestibility in broiler chickens

Abstract

Faba bean seed is a good source of crude protein (CP) (293.06 g/kg DM), however soybean meal (SBM) is the dominant protein source in broiler chicken diets. With air classification technique, faba bean seeds can separate to starch and protein rich fractions. Faba bean protein (FBP) (airclassified) may be a superior protein source compared to SBM for broiler chickens. This study was conducted to compare SBM and FBP in broiler chickens fed with both pelleted and extruded diets. After air classification, the CP content of FBP was 632.41 g/kg DM. Pelleting and extrusion processes were used to produce the SBM and FBP based diets. Physical feed quality was analyzed by hardness, pellet durability index (PDI), particle size distribution, expansion rate, and water stability. The broiler chicken performances (body weight, feed intake, and feed conversion ratio) were lower in the group fed FBP diets compared to the SBM fed group. The poor performance could be caused by anti-nutritional factors (especially heat-stabile NSP and RFOs). The protein digestibility was analyzed in the digesta content of the upper jejunum, lower jejunum, upper ileum, and lower ileum. FBP extruded (0.902) had the highest protein digestibility followed by FBP pelleted (0.875), SBM extruded (0.824), and SBM pelleted (0.813). The limitation of FBP diets on broiler chicken performances should be investigated closely.