This study aims to evaluate the effect of treated linseed meal or cotton seed meal with different levels of condensed tannins (quebracho tannins, QT; Unitan, Argentina) on Zaraibi dairy goats and their offspring performance. Both protein sources were treated with four levels of tannin (1, 2, 3 and 4 %) on dry matter basis.  An in situ experiment was conducted to study the effect of treatment on the rate of disappearance of DM, OM and CP in the rumen using a pair of cannulated buffalo mature bulls where they were fed on clover hay by 1/3 of their daily requirements while concentrate feed mixture given by 2/3 of the animal requirements. According to the results of in situ degradation trial, two better CFM's in addition to the two untreated meal were fed to thirty two Zaraibi goats (BW 51.5± 1.75 Kg). They were randomly divided into four similar groups (8 does/ each) where the untreated groups (R1 and R3)fed 60% CFM contained untreated linseed meal or cotton seed meal respectively, and 40% rice straw. The two treated groups were fed 60% CFM contained treated linseed meal or cotton seed meal by quebracho tannin (QT) at the rate of 2% plus 40% rice straw (R2 and R4, respectively) on DM basis for all rations. Nutrients requirements were calculated according to NRC (1994). At the end of the experiment digestibility trails were conducted to estimate the digestibility and feeding values of the experimental rations using acid insoluble ash technique (using 3/g goats) for each trial. Results indicated that in situ degradability of DM and OM were significantly decreased with increasing the level of tannin up to 4% and also, crude protein degradability values followed similar trend to that of DM and OM among treatments. In other words, the UDP was increased as increasing tannin levels into the highest level (4%). Insignificant differences among different experimental treatments were showed for digestibility coefficients of all nutrients expect of CP which was significantly higher for R2 and insignificantly higher with R4 than that ofcroesponding untreated group R1 which had lower value of digestion coefficient of CP and there is no significant difference between R1 and R3. No significant differences were observed between R2, R3 and R4 in DCP values, however, R4 had higher significant differences with R1. While TDN values were quite similar among treatments. Daily milk yield for R2 and R4 rations were significantly (P<0.05) higher as compared with that of R1 and R3 with the highest value occurred with R4. No significant differences were noticed among experimental rations in all milk constituents except for fat percentage which reduced significantly with R4 vs R3. In matching with milk yield, protein yield for R2 and R4 were significantly higher (P<0.05) than those of untreated groups (R1 and R3), while fat yield was insignificant increased by dietary treatments.  Daily gain for kids from birth up to weaning was significantly (P<0.05) higher for treated rations than kids fed untreated ones by tannins (R1 and R3). Also, results indicated that the untreated rations (R1 and R3) gave the lowest conception rate (25.0%), while groups fed R2 and R4 gave 75.0 and 87.5%,  respectively, conception rate with significant differences due to QT treatments for both kind of protein sources. Based on these results, it could be concluded that the protection process of linseed meal and cotton seed meal with 2% QT can improved the CP utilization and dairy goats performance.