Effect of extruded full-fat soybeans on performance, amino acids digestibility, trypsin activity, and intestinal morphology in broilers

The influence of different levels of extruded full-fat soybean (EFFSB) in the diet on growth performance, apparent ileal amino acids digestibility (AIAAD), intestinal morphology, and trypsin activity in digesta of broilers was determined. In the first experiment, two-hundred sixty ROSS 308 male chickens were used to investigate the effect of EFFSB on growth performance, intestinal morphology, and trypsin activity in the digesta and AIAAD. Five dietary treatments were used, containing 0, 40, 80, 120, and 160 g/kg of EFFSB. The experiment lasted from day 10 till day 38 of age. The inclusion of EFFSB at the level of 160 g/kg in the diet significantly (P < 0.05) decreased final body weight (2443 g in 0 group vs. 2093 in 160 group) and worsened feed efficiency. AIAAD was lower when diet contained more than 40 g/kg EFFSB. But at the level of 160 g/kg AIAAD increased in several amino acids (threonine, isoleucine, leucine, histidine). Trypsin activity increased with increasing EFFSB in the diets. There were no significant (P > 0.05) differences in AIAAD between groups 80, 120, and 160. Villus height (groups 0: 966.2; 4: 852.1; 8: 792.6; 12: 836.3; 16: 926.7 µm) and crypt depth (groups 0: 160.1; 4: 134.8; 8: 122.9; 12: 129.5; 16: 134.6 µm) of ileum decreased with inclusion of EFFSB in the diet, but villi/crypt ratio increased. In the second experiment, male chickens ROSS 308 were divided into 4 groups with 2 replicates per 100 chicks each. The groups were fed 0, 40, 80, and 120 g/kg of EFFSB. The experiment lasted from day 10 till day 38 of age. Final body weight (2594 g in 0 group vs. 2624 g in 120 group) was not significantly (P > 0.05) affected by the diet. The study showed that EFFSB at the level of 120 g/kg in grower broiler diet had no adverse effect on performance.