In this study, the weight of the twelve cows was ranging from 435-570kg. The animals in this study were in the 2^nd to 4^th lactation season. In order to study the production of milk and its composition by the effect of the tested rations, cows were subdivided into four groups (three cows in each group). According to NRC (2001) recommendations all groups were fed individually. The period of the experiment was 140 days (20 weeks) after 6 weeks from calving. The four experimental rations as DM were formulated nearly as follows : control: 52% concentrate feed mixture (CFM) (40% corn grain, 30% wheat bran, 23% undecorticated cottonseed meal, 5% molasses, 0.5% salt and 1.5% limestone) + 20% corn silage (CS) + 28% rice straw (RS), experimental ration 1 (Exp.1): 52% CFM (35% corn grain, 30% wheat bran, 10% corn gluten feed (CG), 18% undecorticated cottonseed meal, 5% molasses, 0.5% salt and 1.5% limestone) + 20% CS + 28% RS, (Exp.2): 52% CFM ( 32.5% corn grain, 30% wheat bran, 15% CG, 15.5% undecorticated cottonseed meal, 5% molass, 0.5% salt and 1.5% limestone) + 20% CS + 28% RS and (Exp.3): 52% CFM (30% corn grain, 30% wheat bran, 20% CG, 13% undecorticated cottonseed meal, 5% molasses, 0.5% salt and 1.5% limestone) + 20% CS + 28% RS. The dry matter intakes (% body weight) were higher with feeding on Exp.1 or Exp.2 (3.38 and 3.51) respectively, than feeding on control or Exp.3 (3.25 and 3.26, respectively). There was no significant effect on the average daily milk yield with feeding the experimental rations from Week 1 to Week 20. The average daily milk yield results were 13.68, 14.71, 15.73 and 14.79 Kg /day with feeding on the control, Exp.1, Exp.2 and Exp.3, respectively. The highest value was with feeding on Exp.2 than the other rations. Regarding the milk composition, protein (%( was higher (p <0.05) with feeding on Exp.1 than feeding on Exp.2 or Exp.3 (2.42, 2.26 and 2.28) respectively, but there was no significant effect with the control ration (2.37) and there was no significant effect between the control and Exp.3. Milk total solids (%), fat (%), lactose (%), solids non-fat (%), net energy of lactation (Mcal /Kg), fat corrected milk (Kg / day), fat yield (Kg / day), protein yield (Kg / day) and lactose yield (Kg / day) did not significantly affect by dietary treatments. The best values of feed conversion (dry matter intake Kg/Kg fat corrected milk) were with feeding on rations containing corn gluten feed: Exp.1, Exp.2 and Exp.3 (1.15, 1.14 and 1.16) respectively, than the control (1.27) which was without corn gluten feed. The highest values of the profit (LE) were with feeding on Exp.1, Exp.2 and Exp.3 (29.08, 30.64 and 30.32) than feeding on the control one (23.72), respectively. The replacement of amounts of corn grain and cottonseed meal in the concentrate feed mixture in lactating cows rations by 15% corn gluten feed are often considered for enhancing production of milk, persistency and economic efficiency.