Abstract
This study aimed to evaluate the effects of modified corn straw dietary fiber (MCDF) on growth performance, nutrient metabolism, serum biochemistry, antioxidant capacity, intestinal morphology and hepatic lipid deposition in broilers. A total of 200 one-day-old Arbor Acres broilers were randomly allotted to four groups: the control group was fed basal diet, while three treatment groups supplemented with MCDF at 0.5%, 1%, and 1.5% of the basal diet, respectively. The results revealed that MCDF reduced ADG (p = 0.008) and increased feed/gain (p = 0.028) in the early stage, with no significant effects on ADG and feed/gain in the later or overall rearing periods (p > 0.05). In the early stage, 1% and 1.5% MCDF reduced ether extract metabolizability (p = 0.001), and 0.5-1.5% MCDF reduced phosphorus metabolizability (p < 0.001). Compared to the control group, 0.5-1.5% MCDF had no significant effects on nutrient metabolism in later stage and slaughter performance, but it reduced the 24 h pH of breast muscle and serum levels of LDL-C, HDL-C, TG, TC, and GLU (p < 0.05). The 1% MCDF decreased L* at 15 min and 24 h of leg muscle (p < 0.05). The 0.5% and 1% MCDF increased serum T-AOC levels and 1% MCDF increased CAT (p < 0.05), whereas 1.5% MCDF decreased SOD (p < 0.05). MCDF increased the villus height-to-crypt depth ratio by reducing crypt depth (p < 0.05) and improved the histomorphology of hepatocytes, accompanied by a reduction in the number of lipid droplets in the liver. Therefore, 0.5-1.5% MCDF can be recommended in broiler diets in the later stage, as it had no negative effects on growth performance, nutrient metabolism, and effectively reduced blood lipids and glucose levels, enhanced antioxidant capacity, and ameliorated hepatic vacuolar degeneration and lipid deposition.