Effects of dietary distillers dried grains with solubles (DDGS) on growth performance, oxidative stress, and immune function in broiler chickens

Distillers dried grains with solubles (DDGS) from corn contain relatively large amounts of polyunsaturated fatty acids and some yeast components, which may increase oxidative stress and alter immune function, respectively, when fed to broilers. Therefore, the study was undertaken to assess the effects of distillers dried grains with soluble (DDGS) on broilers under immunosuppressive challenge. One-day-old male broiler chickens (300) were assigned to 2 treatments with 6 replicates pretreatment. Birds were fed diets formulated to contain 0, 15% corn-based DDGS, respectively. The experimental diets were fed for 6 weeks in 2 phases. On day 21, serum IgA, IgG content and malondialdehyde (MDA), glutathione peroxidase (GSH-Px), total superoxide dismutase (T-SOD), and total antioxidant activity (T-AOC) capacity were analyzed. Chickens were then randomly allotted to 1 of 4 treatment groups: negative control (NC) corn-soybean meal diet without dexamethasone (DEX) challenge, positive control (PC) corn-soybean meal diet with (DEX) challenge, 15% DDGS without DEX challenge (D), 15% DDGS with DEX (D+DEX). Based on these results, dietary DDGS did not influence ADG, ADFI and F:G of 21 d, 28 d and 42 d chicks (P > 0.05), however, DEX affected ADG and F:G of 28 d chicks remarkably (P < 0.05). Relative weights of liver, abdominal fat, spleen, thymus, and bursa were influenced by DEX challenge on d 28 (P < 0.05). DDGS reduced serum T-AOC, T-SOD, whereas increased IgA, IgG and MDA of 21-day-old broilers significantly (P < 0.05). Dietary DDGS also reduced liver T-SOD of 21-day-old broilers significantly (P < 0.05). Based on real-time PCR, 28 d chicks fed DDGS had a greater relative abundance of mRNA encoding IL-4 and IL-6 (P < 0.05), whereas DEX decreased the expression of GPX, IL-6, IL-10 (P < 0.05). Thus, 15% dietary DDGS inclusion has the beneficial effects on immune functions for broilers to some degree.