The effect of corn dried distillers grains with solubles (DDGS) on milk yield, milk composition and body weight (BW) and digestibility were evaluated by using lactating ewe (Exp. 1) and Awassi ewe lambs (Exp. 2). Dietary treatments were (1) no DDGS (CON), (2) 200 gkg À1 DDGS (DDGS200) or (3) 300 gkg À1 DDGS (DDGS300) of dietary dry matter (DM). In Exp. 1, 30 lactating Awassi ewes were randomly assigned to the corresponding diets. Nutrient intakes were determined daily throughout the experiment which lasted for 8 weeks. Body weights of ewes and lambs were measured on days 0, 28 and 56 of the study whilst milk yield and composition were recorded on days 18, 36 and 54. Ewe BW changes were similar amongst treatments. Ewes consuming the DDGS diet showed increased milk production (p<.045) over those provided the CON diet. Cost of diets and milk production reduced (p¼.01) in DDGS-containing diets compared with the CON diet. In Exp. 2, 18 Awassi ewe lambs were randomly assigned into the same dietary treatments and fed their diets for 21 days. Digestibility of DM and ADF was lower (p<.017) for the CON diet than for the DDGS diets. Digestibility of CP and NDF increased (p<.036) in the DDGS200 diet than the CON diet. Results indicate DDGS has the potential to be included up to 300 gkg À1 of dietary DM of DDGS in Awassi ewes' diets with no negative effects on production parameters whilst being cost effective. HIGHLIGHTS Cost of feed and milk production decreased in DDGS diets. Milk production increased in DDGS diets. Milk composition was similar among diets.