Effect of dietary folic acid and energy density on immune response, gut morphology, and oxidative status in blood and breast muscle of broiler chickens

Folic acid (FA) plays an essential role in the functioning of the gut and serves as an antioxidant. Therefore, dietary supplementation with high levels of FA may improve gut health and prevent oxidative stress caused by feeding a high energy density diet to broiler chickens. Broiler chickens were assigned into eight treatments, consisting of either a normal energy (NE) or high energy (HE) density diet, and four FA levels (2.2, 5, 10, and 15 ppm). Data were analyzed by SAS 16 GLM procedure. Birds fed HE diets had increased (P<0.05) plasma concentrations of calcium and albumin but reduced (P<0.005) weights of ceca and bursa compared to those fed NE diets. Dietary supplementation with 10ppm FA significantly increased (P<0.05) birds’ heart weight and bile acid concentration. FA and energy density interactions were significant for jejunal villus height (VH; P=0.0226), villus width (VW; P<0.0001), and crypt depth (CD; P=0.0332). Among the NE group, birds fed 5-15ppm FA had reduced (P<.0001) VW, while in the HE groups, 15ppm FA supplementation resulted in an increased jejunal VH (P=0.0317) compared to other treatments. In conclusion, dietary supplementation with increased levels of FA in HE diets could be beneficial for the intestinal health of broiler chickens.