We aimed to evaluate intake, milk yield, and composition of lactating goats using corn silage with the addition of spent substrate from white rot mushroom culture (SSWRMC). We based our treatments on the enzymatic activity: 0; 1100 and 3300 U lignocellulolytic enzymes (LE)/min/kg of fresh material (FM). The enzymatic activity (U/min/g of SSWRMC) was determined to laccase (390.28), ligninperoxidase (176.27), Mnperoxidase (12.56) and cellulase (2,893.98) enzymes. The diets were formulated to meet the nutritional requirements of lactating goats producing 3 kg milk/day (crude protein: 14.6% and TDN: 74.3%) and body weight of 60 kg and the silage corresponded 60% of the diets. The experiment was designed in a triple Latin square (3 × 3) with periods of 22 d (19 d of adaptation and 3 d of sample collection). The milk composition was determined by infrared spectroscopy and total polyphenol by colorimetric method (expressed gallic acid - EqGA). Results were analyzed using the MIXED procedure SAS for linear and nonlinear regression. There were no changes (P > 0.05) on corn silage chemical composition (DM,CP, NDF, NFC) with different level of SSWRMC addition. There were no effect of treatments (P > 0.05) on dry matter intake (2.9 ± 0.36 kg/d), milk production (2.81 ± 0.68 kg/d) and composition (average: total solid = 10.92%; protein = 2.94%; fat = 2.85%; lactose = 4.22%; milk urea nitrogen = 12.18 mg/dL). However, the total polyphenol concentration in the milk linearly increased (P = 0.01) (10,401.78; 10,695.00; 12,694.55 mg EqGA/L, level 0; 1100 and 3300 U/min of LE/kg FM, respectively). This increase is likely associated with the enzymes activities in SSWMC that act in phenolic structures during the lignin cleavage. The increased capacity to transfer polyphenols to the milk can be positive to human health, due to its effects to reduce free radicals. In conclusion, the addition of SSWMC in corn silage increased polyphenols concentration in milk, without changing milk composition, which can be beneficial to human and animal health.