Impacts of Solid-State Fermented Barley with Fibrolytic Exogenous Enzymes on Feed Utilization, and Antioxidant Status of Broiler Chickens

SIMPLE SUMMARY: The efficient feed utilization of raw feed ingredients is one of the main factors associated with superior growth and production in poultry farming. The higher demand for cereal grains as energy sources has encouraged the dietary inclusion of other alternative cereals to achieve the target poultry production. However, alternative cereals such as barley grains may limit poultry growth due to their higher content of anti-nutritional factors, such as non-starch polysaccharides (NSPs). Hence, the application of solid-state fermentation technology with fibrolytic enzymes allows for a higher dietary inclusion of barley comparable to its actual inclusion levels. In this study, including 10% fermented and enzymatically treated barley not only improved feed utilization efficiency, but also modified intestinal barrier functions and antioxidant status and upregulated the expression of nutrient-transport-related genes. Therefore, fermented and enzymatically treated barley can be used as a promising alternative to corn and achieve the target production of broiler chickens. ABSTRACT: The present and future high demand of common cereals as corn and wheat encourage the development of feed processing technology that allows for the dietary inclusion of other cereals of low nutritional value in poultry feeding. Barley grains contain anti-nutritional factors that limit their dietary inclusion in the poultry industry. The treatment of barley with solid-state fermentation and exogenous enzymes (FBEs) provides a good alternative to common cereals. In this study, barley grains were subjected to solid-state microbial fermentation using Lactobacillus plantarum, Bacillus subtilis and exogenous fibrolytic enzymes. This study aimed to assess the impact of FBEs on growth, feed utilization efficiency, immune modulation, antioxidant status and the expression of intestinal barrier and nutrient transporter-related genes. One-day-old broiler chicks (Ross 308, n = 400) comprised four representative groups with ten replicates (10 chicks/replicate) and were fed corn-soybean meal basal diets with inclusions of FBEs at 0, 5, 10 and 15% for 38 days. Solid-state fermentation of barley grains with fibrolytic enzymes increased protein content, lowered crude fiber and reduced sugars compared to non-fermented barley gains. In consequence, the group fed FBEs10% had the superior feed utilization efficiency and body weight gain (increased by 4.7%) with higher levels of nutrient metabolizability, pancreatic digestive enzyme activities and low digesta viscosity. Notably, the group fed FBEs10% showed an increased villi height and a decreased crypt depth with a remarkable hyperactivity of duodenal glands. In addition, higher inclusion levels of FBEs boosted serum immune-related parameters and intestinal and breast muscle antioxidants status. Intestinal nutrient transporters encoding genes (GLUT-1, CAAT-1, LAT1 and PepT-1) and intestinal barriers encoding genes (MUC-2, JAM-2, occludin, claudins-1 and β-defensin 1) were upregulated with higher dietary FBEs levels. In conclusion, feeding on FBEs10% positively enhanced broiler chickens’ performance, feed efficiency and antioxidant status, and boosted intestinal barrier nutrient transporters encoding genes.