Feed enzymes, probiotic, or chitosan can improve the nutritional efficacy of broiler chicken diets containing a high level of distillers dried grains with solubles

The aim of the experiment was to evaluate the effect of selected feed additives on performance, nutrient digestibility, meat quality, and bone characteristics of broiler chickens fed diets containing a high level of corn dried distillers grains with solubles (DDGS). A total of 480 one-day-old Ross 308 male chicks were randomly allocated to 1 of 8 treatments, each comprising 6 replicate cages with 10 birds per cage. In a 6-wk experiment, chickens were fed isocaloric and isonitrogenous experimental diets containing 0 (control) or 120g (starter phase) or 180g (finisher phase) DDGS/kg. The diet containing DDGS was not supplemented or supplemented with feed enzymes [200mg of enzyme with endo-1,4-β-xylanase activity (1000 fungal xylanase units/g)/kg, 200mg of enzyme with phytase activity (10,000 phytase units/g)/kg], 700mg sodium butyrate/kg, 108 cfu probiotic bacteria (Lactobacillus salivarius)/kg, 250mg of each herb extract (Taraxaci siccum, Urticae siccum, and Salviae siccum)/kg, 5g inulin/kg, or 3mL chitosan/kg. The incorporation of DDGS into the diet had no effect on growth performance at 21 and 42d of age and breast meat proximate composition, but negatively affected (P<0.05) apparent digestibility of dry matter and organic matter, metabolizable energy content of the diet, and retention of N and Ca. Inclusion of DDGS increased (P<0.05) the percentage of linoleic acid and total polyunsaturated fatty acids (PUFA), and decreased (P<0.05) the content of palmitic and stearic acid, as well as total monosaturated (MUFA) and saturated fatty acids (SFA) in breast lipids. At 42d, incorporation of DDGS into the diet decreased (P<0.05) bone breaking strength of femurs, without any effect on tibia indices. Some of the additives, i.e., feed enzymes, probiotic, or chitosan, improved (P<0.05) growth performance during either the first, second, or for the entire feeding period, nutrient digestibility, and retention of N and Ca. Feed enzymes also increased (P<0.05) bone breaking strength, yielding load, and stiffness of femurs. The results of this study indicate that DDGS can be included at a level of 120 (starter) or 180g (finisher)/kg in the diet of broiler chickens without any detrimental effect on performance, and feed additives such as enzymes (xylanase+phytase), probiotic, and chitosan can increase the nutritional efficacy of the diets with a high level of DDGS.