Effects of corn distillers dried grains with solubles on performance, oxidative status, intestinal immunity and meat quality of Chinese Yellow broilers
Globally, the availability of distillers dried grains with solubles (DDGS) and especially that from corn is increasing annually from the production of biofuel. China is one of the biggest producers of corn DDGS, ranking third after Brazil and the U.S.A (Jie et al., 2013). Corn DDGS, a by‐product of ethanol industry, has used as a feedstuff because it contains several important available nutrients (protein, fat, essential fatty acids, vitamins, minerals, xanthophylls and yeast β‐glucan, mannan polysaccharides, and nucleotides) (Salim et al., 2010; Sun et al., 2013; Min et al., 2015; Alizadeh et al., 2016), which has been demonstrated to be an acceptable ingredient for broiler diets (Lumpkins et al., 2004; Batal and Dale, 2006; Wang et al., 2007; Shim et al., 2011). Its inclusion in mixed feeds reduces NH3 and H2S emission from poultry manure (Wu‐Haan et al., 2010; Li et al., 2014) and lowers feed cost (Cheon et al., 2008). Slominski (2012) showed that corn DDGS as yeast‐derived products contains approximately 6% yeast biomass, which could be potentially beneficial for gut development and health and effective in immune system stimulation. Perez et al. (2011) found that 10% corn DDGS was beneficial for intestinal health and altered caecal microbiota in young chicks. In addition, inclusion of corn DDGS in broiler diets improved meat quality and enhanced immune responses by upregulating gene expression of IL‐4 and IL‐6, and antibody production (Min et al., 2012, 2015), while in laying hens, corn DDGS improved egg yolk colour and enhanced its content of polyunsaturated fatty acids and lutein (Sun et al., 2013; Świątkiewicz et al., 2013). Corn DDGS contains high levels of polyunsaturated fatty acids (PUFAs), particularly oleic acid and linoleic acid, that are vulnerable to lipid peroxidation (Seppanen, 2005; Corzo et al., 2009; Stein and Shurson, 2009). Therefore, feeding corn DDGS containing oxidized lipids may induce oxidative stress, alter immune function and, thus, negatively affect animal growth performance (Song et al., 2012a). The optimal dietary levels of corn DDGS have been estimated for broiler chickens, laying hens, turkeys, quails, Peking ducks, geese and rabbits. There have been no studies optimizing the level of corn DDGS in diets including relative antioxidant function and immunity for Chinese Yellow broilers, typical of western broilers but very important in Asia because of the popularity of their meat. The goal of this study was to estimate the optimal level of corn DDGS in diet of Chinese Yellow broilers based on their growth performance, meat quality, and indicators of metabolic and antioxidant status and immunity.