LAUSR

The objective of this study was to investigate the effects of soybean meal (SBM) treated with acetic or citric acids on growth performance, microbial population, digestive enzyme activities, nutrient digestibility, and jejunal morphology in broiler chickens. A total of 350 one-day-old male broiler chicks (Ross 308) were randomly distributed into 7 experimental groups with 5 replicates per each. Experimental treatments were diets containing untreated SBM (control) and SBM treated with two acid sources and their concentrations including 5, 10, and 15% acetic acid (A1, A2, and A3) or 0.25, 0.50, and 0.75% citric acid (C1, C2, and C3). Results showed that trypsin inhibitors and lectins as the main SBM anti-nutrients significantly reduced in acid-treated SBM compared with untreated SBM (P < 0.05). During 1-24 days, body weight gain increased in chicks fed the C2 diet (P < 0.05). Feeding of the C2 diet increased feed intake compared with A1, A2, and C3 groups (P < 0.05). Feed conversion ratio improved in chicks fed with C2, C3, and A2 diets compared with the control group (P < 0.05). The greatest villus length, villus length to crypt depth ratio, and villus surface area were observed in the C2 diet (P < 0.05). A significant increase in protease and lipase activity was found in broilers which received a C2 diet compared with the control group (P < 0.05). Broiler chickens fed with the C2 diet had a higher organic matter and crude protein digestibility than the chicks which received the control diet (P < 0.05) and dry matter digestibility was the lowest in broilers fed with the A3 diet (P < 0.05). In conclusion, the acid hydrolyzing process had a beneficial effect on the nutritional value of SBM. In addition, data showed that acid-hydrolyzed SBM had the potential to exert positive influences on growth performance, jejunal morphology, and nutrient utilization in broiler chickens.