Impacts of Irradiated Distillers Dried Grains with Solubles (DDGS) as dietary Supplement on Physiological and Biochemical Aspects of Growing Rabbits

Abstract

D istillers dried grains with soluble (DDGS) are a co-product of ethanol production from starch cereals (mainly corn). Dietary fiber is the sum of carbohydrates and lignin that are resistant to digestion by the small intestine enzymes. DDGS contains approximately 3 times dietary fiber more than corn. Dietary fiber in DDGS consists mainly of insoluble dietary fiber. The present study was conducted to evaluate the effect of gamma (γ) irradiation on crude fiber, soluble fiber and non-soluble fiber of irradiated corn DDGs at different doses 0, 10, 20 and 30kGy, and to evaluate the effect of feeding irradiated DDGs for rabbits and their effects on rabbit’s performance (body weight, gain weight, feed intake, feed conversion, water intake, rectum temperature and respiration rate), apparent digestibility (dry matter, crude protein, crude fiber and ether extracts), carcass traits (carcass weight, dressing (%) and prime cuts (%) and blood biochemistry (AST, ALT , total protein, albumin, globulin, creatinine, total lipids, total cholesterol, and blood urea). Sixty New Zealand White weaned male rabbits of 35 days age were randomly divided to 4 treatment groups of approximately equal average weight (706g) with 15 animals each. The first group was fed the basal diet supplemented with 10% DDGS (non irradiated) (control), 2 nd, 3rd and 4th groups were fed the control diet supplemented with 10% irradiated DDGS at 10, 20 and 30kGy, respectively. The obtained results revealed a decrease in crude fiber and increases in soluble fiber and insoluble fiber. The increases were linearly correlated with the increasing irradiation dose. The supplemented irradiated 10% DDGS up to 30kGy in the diet of growing rabbits resulted in a significant improvement of body weight, gain weight, feed conversion, the apparent digestibility of dry matter, crude protein, crude fiber, carcass traits (carcass weight, dressing (%) and prime cuts(%)), and the improvement was parallel with increasing the radiation dose. While, feed intake, water intake, rectal temperature, respiration rate, ether extracts digestibility, AST, ALT , total protein, albumin, globulin, total lipids, total cholesterol, creatinine and blood urea were not altered by the treatments. Generally, it can be concluded that radiation processing with γ-rays improved the soluble and insoluble fiber and the digestibility of DDGS, and that DDGS supplemented diets fed to growing rabbits improved rabbits' growth performance without any deleterious effect on physiological and biochemical attributes.