This study evaluated the effects of incorporating varying levels of dried distillers’ grains with solubles (DDGS) and non-starch polysaccharide (NSP) enzymes into broiler diets on growth performance, immune function, intestinal histomorphology, and economic efficiency.

A total of 240 one-day-old broiler chicks (Avian 48; initial weight 51.57 ± 4.6 g) were randomly assigned to eight dietary treatments consisting of four DDGS inclusion levels (0, 5, 10%, or 20%) provided either with or without NSP enzyme supplementation.

Results showed that moderate DDGS inclusion levels (5–10%) combined with enzyme supplementation improved body weight gain and feed conversion ratio during the starter and grower phases, whereas 20% DDGS without enzymes negatively affected performance. Most serum biochemical parameters were unaffected (p > 0.05), although triglycerides and globulin levels increased significantly (p < 0.05) in enzyme-supplemented groups. Additionally, birds receiving enzyme supplementation exhibited significantly higher IgA and IgM levels, along with elevated white blood cell counts and H/L ratios at the 5% and 10% DDGS levels. Histological analysis revealed improved villus height and crypt structure in enzyme-supplemented groups, while 20% DDGS without enzymes adversely affected gut morphology.

Economically, the 5% DDGS diet with enzymes achieved the lowest cost and highest net profit, whereas the 20% DDGS group without enzymes showed the poorest economic return. Overall, incorporating DDGS at 5–10% with enzyme supplementation enhanced growth performance, immune response, and intestinal health in broilers without compromising physiological functions.