The effect of direct-fed microbials, fermentation products (FP) and digestive enzymes on milk yield and milk composition was evaluated in dairy cattle. Lactating Holstein dairy cows (n = 40) from a commercial dairy herd were divided in 4 groups (n = 10 each) and blocked by days in milk (DIM; < 100 DIM or ≥100 ≤ 171 DIM) and balanced by parity number. Animals had a 2-week adaptation period. The balanced groups were randomly assigned to one of the following treatments: Control (C): 21g wheat middling; Treatment 1 (T1): 21g of a commercial mixture of A. oryzae FP, B. subtilis FP, L. acidophilus FP, yeast and amylase. Treatment 2 (T2): 18g Wheat middlings + 3g of a commercial mixture of A. niger FP, A. oryzae FP, α amylase, pectinase, endo- glucanase, β- glucanase, xylanase, and mannanase. Treatment 3 (T3): 11g Wheat middlings + 10g of a commercial mixture of B. subtilis, amylase and α amylase. Each treatment was top-dressed on the pelleted feed offered at the parlor during every morning milking. Milk production by cow was collected twice a day for 14 weeks using the AfiLab AfiMilk system. Milk urea nitrogen (MUN) and ketone body concentrations in milk by cow was collected once a week for 14 weeks using the Porta BHB milk ketone test and MUN was determined by the Teco Diagnostic Vet- MUN Reagent strips. There was no interaction between treatment, parity and/or period (P > 0.10). Average milk production (kg/cow/per day) during the experiment was C 21.4 ± 2.12; T1 19.7 ± 2.11; T2 19.8 ± 2.23; T3 21 ± 2.11 (P > 0.05). Average milk BHB concentration (μmol/L) per treatment was C 90.29 ± 13.08; T1 100.39 ± 12.04; T2 89.71 ± 13.12; T3 99.17 ± 12.57 (P = 0.2121). Treatment neither had an effect on MUN. Mean MUN (mg/dL) per treatment was C 8.42 ± 1.3; T1 8.38 ± 1.20; T2 8.58 ± 1.44; T3 8.63 ± 1.26 (P = 0.8533). In conclusion, in this experiment under tropical conditions, DFM, FP and digestive enzymes, resulted in no change in milk production, MUN and BHB concentrations in milk.