The present study was conducted to investigate the effects of dietary different levels of olive cake (OC) on laying hens' performance and some blood constituents under Egyptian desert conditions. A total number of 150 Mamora laying hens (22 weeks old and body weight of 1461.20 ± 30.74 g) were used until 34 week of age. One hundred and fifty hens were randomly distributed into five equal treatments (30 hens of each) and randomly distributed into three equal replicates (10 hens each). The 1st treatment was fed a basal diet as a control (0 % OC), while, the 2nd, 3rd, 4th and 5th treatments were fed diets containing 4, 8, 12 and 16 % OC, respectively.
The results showed that hens fed 12 and 16 % OC recorded an increase (P<0.05) in egg weight by 4.9 and 2.9 %, respectively, while, shell thickness was decreased (P<0.05) in 8, 12 and 16 % OC as compared to control group. However, egg number was decreased (P<0.05) in 12 and 16 % OC as compared to those fed based diet.
Hens fed 16 % OC showed a significantly decreases in the count of red blood cells, hemoglobin and albumin concentrations as compared to other treatments. While, diets containing 4, 8, 12 and 16 % OC significantly reduced the levels of cholesterol and triglycerides concentrations compared to the control group. Hens fed 16 % OC showed significantly increased in aspartic transaminase concentration as compared to other treatments, while, total antioxidant capacity was decreased (P<0.05) in the hens fed 16 % OC as compared to the hens fed 4 % OC and control group. Conclusively, olive cake could be successively and safely included up to 12 % in laying hens diets without adversely effect on productive performance and blood constituents under Egyptian desert conditions.