This study aimed to investigate the impact of adding chromium methionine, non-protected niacin and yeast on the nutrient digestibility, some blood serum parameters and the productive performance of dairy cows. Twenty lactating cows at early lactation with an average LBW of 550.33±11.64 kg were randomly allocated to four groups of five cows each, based on LBW and previous milk yield. All animals were fed individually on a basal ration containing 50% concentrate feed mixture, 25% fresh berseem, and 25% rice straw (on a DM basis) to cover the nutrient requirements, according to NRC (1989). The control group (T1) was un-supplemented. The remaining groups, T2, T3, and T4, were supplemented with 5 g/h/d of chromium methionine (Cr-Met), 10 g/h/d of non-protected niacin, and 10 g/h/d of yeast, respectively. Results revealed that the treatments had no effect on dry matter intake (DMI). Most of the nutrient digestibility, feeding values, milk yield, feed conversion ratio, and economic efficiency were significantly (P<0.05) improved in the treated groups. The yeast group, followed by the niacin and Cr-Met groups produced significantly more actual milk and 4%-Fat corrected milk yield per day. Niacin and Cr-Met dietary led to enhanced milk composition. Most of the blood measurements showed no significant differences among groups. Niacin and Cr-Met supplements improved kidney functions. The IgM levels were significantly (P<0.05) higher in the supplemented groups. Finally, dairy cows supplemented with additives, especially yeast, showed increased milk production and improved nutrient digestibility, feed conversion, economic efficiency, and immunity without negatively affecting their health.