Twenty-four multiparous Murciano-Granadina dairy goats in mid-lactation (wk 8 to 30) were used a single cross-over design to evaluate the effects of supplementation with an exogenous fi brolytic enzyme preparation, characterized by cellulase and xylanase activities, on feed intake, milk yield and composition, and liveweight and body condition changes. Goats received ad libitum a basal total mixed ration composed of 65% forage and 35% concentrate. The treatments were: control (without enzyme) and experimental with enzyme (included at the recommended commercial dose of 4.7 ml/kg concentrate). Feed intake, milk yield, 4% fat corrected milk yield, and milk composition were not affected by enzyme supplementation, although milk casein content tended to decrease in the enzyme treatment. Body weight change tended to be higher with the enzyme treatment.