Forty female Barki goat does were used to investigate the effect of inclusion of sugar beet pulp (SBP) treated with urea at levels of 2, 4 and 6% urea to replace about 30% of common concentrate feed mixture in the diet of goats on lactating goat performance, milk yield and composition, birth and weaning weight. Five experimental diets were formulated: T1 (control): concentrate feed mixture (CFM)+ berseem hay (BH), T2: CFM + untreated SBP+BH, T3: CFM+SBP treated with 2% urea on DM basis+ BH, T4: CFM + SBP treated with 4% urea on DM basis+ BH and T5: CFM + SBP treated with 6% urea on DM basis+ BH. The experiment feeding period lasted for 140 days. At the end of lactation stage a digestibility trial was carried out to study the effect of the experimental diets on digestibility coefficients, rumen parameters, microbial protein, protozoal count, and blood constituents. The obtained results revealed that T5, T4 and T3 increased (P≤0.05) DM, OM, EE, NFE and CP contents, and decreased ash, CF, NDF, ADF, DAL, cellulose and hemicellulose contents as compared to T2 and T1. Urea treatments of SBP increased (P≤0.05) body weight and feed intake. T4 and T5 had the highest (P≤0.05) DM, OM, EE, CP, CF, NFE, NDF, ADF, ADL, cellulose and hemicellulose digestibility coefficients as well as the highest (P≤0.05) TDN and DCP intakes. T4, T5 and T3 improved (P<0.05) nitrogen balance, water balance, rumen fermentations, rumen protozoal count, milk yield and composition, birth and weaning weight. The present study suggests the replacement of dried sugar beet pulp treated with 4% urea by a part of common concentrate feed mixture of lactating goats.