The objective of this study was to investigate the use of distillers dried grains with solubles (DDGS) in rations of barki sheep and its effects on nutrient digestibility and milk production in lactating crossbred Friesian cows. Four total mixed rations (TMR) were formulated to contain 0, 10, 20 and 30% of corn DDGS.Digestibility trails were carried out using 3 meal barki sheep for each diet. Results showed that the animals fed TMR3 with 20% CDDGS recorded significant increase in digestibility of DM, OM and CP (69.69%, 72.97% and 70.89% respectively) compared to other ratios. The nutritive value as DCP increased significantly (P<0.05) with 20% DDGS total mixed ration.  Rumen fermentation parameters were determined using 3 cannulated female barki sheep. The pH values increased, however total volatile fatty acid and ammonia nitrogen (NH₃-N) concentration decreased significantly (P<0.05) with supplement TMR2 andTMR4 (10 and 30% DDGS). While animal fed TMR1and TMR3 showed highest (P<0.05) of total volatile fatty acid. Values of the effective degradability (ED) of dry matter (DM) at assumed ruminal passage rate of (0.039h-0.043^-1) ranged from 43.67 to 46.45%, and exhibited significant decreased (P<0.05) with adding 10, 20, 30%DDGS respectively than control diet. The effective degradable crude protein (EDCP) and ruminal undegradable protein (RUP) ranged from 56.93to48.13% and from 43.07to51.86% respectively for DDGS containing ratios and control ration. A Lactation trial using 16 lactating dairy cows showed significant increase in milk yield and composition (FCM4%- fat) for the 20% DDGS containing rations compared with other diets.