Abstract: Background and Objective: An Egyptian patented product (ZADO®) consists of exogenous enzyme mixture prepared from anaerobic bacterium, improves performance of broilers but not examined in laying hens. Therefore, this study was conducted to assess the impacts of ZADO® on productivity, blood metabolites and enzyme activity in laying hens. Materials and Methods: A total of 280 Hisex Brown laying hens (48 week of age) were used to evaluate the impacts of exogenous xylanases, cellulases, protease and α-amylase enzyme preparations at ensiling (ZADO®) on the productive performance and enzymes activity up to 64 week of age. Hens were divided randomly into 5 treatment groups (basal diets supplemented with 0.00, 0.25, 0.50, 1.00 or 2.00 g kg–1 diet with ZADO®) and housed in individual cages in an open house system under the same managerial conditions. Hens' performance traits were measured every 4 weeks and blood metabolites and enzymes activity parameters for protease and α-amylase were measured at 54 week of age. Results: No significant effects of dietary ZADO® levels on productive performance of laying hens were detected. However, numerically, a slight increase in egg production rate (92.1, 92.5, 93.9, 93.1 and 93.2%), egg mass (55.8, 57.0, 57.0, 56.8 and 57.2 g) and feed consumption (116.3, 115.8, 117.8, 118.2 and 115.9 g hen–1 day–1) were noted for birds fed diet supplemented with 0.00, 0.25, 0.50, 1.00 or 2.00 g kg–1 diet with ZADO®, respectively. Dietary enzymes cocktail increased total protein level in favor of globulin (p<0.05) and dietary 1 g kg–1 ZADO® or more increased total cholesterol level (p<0.05) with no significant impact on neither LDL- nor HDL-cholesterol levels in plasma. Moreover, enzymes supplementation increased enzymes activity in digesta of both proventriculus and ileum (p<0.05). For example, α-amylase activity records were 0.70, 1.50, 2.26, 19.08 and 11.96 g kg–1 (p = 0.037) in proventriculus digesta and 90, 108, 282, 407 and 287 g kg–1 (p = 0.013) in ileum digesta for the 5 treatment groups, respectively. Conclusion: Laying hens' diets supplemented with ZADO® might increase plasma protein and enhance enzymes activity which might reflect into slight increase in hens' productivity.