The objectives of the study were to evaluate the effects of increasing amounts of dry corn gluten feed (DCGF) in replacement of corn silage in the ration of dairy cows on the lactation performance and the digestibility parameters. For that, 8 lactating Holstein primiparous cows were randomly assigned in a 4x4 Latin square design with 4 week periods and received control 50% forage (35% corn silage and 15% wheat straw) diets or diets containing 10%, 18% or 25% DCGF in replacement of corn silage (L-DCGF, M-DCGF and H-DCGF, respectively). The incorporation of DCGF has significantly modified the physical traits of the diets by increasing the proportion of small particles (<8 mm) and decreasing the pef (physical effectiveness factor) leading to significant decreases in the peNDF (physically effective neutral detergent fibre) and in the NDF intake according to the dietary DCGF content. In parallel, the apparent digestibility of NDF and crude protein was significantly depressed but the effective degradability of starch, crude protein and organic matter in rumen were significantly enhanced when DCGF was added to the diet. In addition, the milk production and quality remained similar whatever the diet regimen used. These results show that the dietary incorporation of DCGF up to 25% did not induce unfavourable effects on the mill: production and composition in dairy primiparous cows.