A total number of 105 Lohman laying hens, 22 weeks of age were used to study the effect of using canola meal treated by clay on laying hen performance under desert condition. Hens were divided equally into seven treatment groups; three levels of CM (10, 15 and 20 %) and two levels of clay (0 and 2%), in addition to control group. Each group contains five replicates with 3 birds each.
Canola meal had a moderate levels of most amino acids but higher levels of methionine and arginine (1.50 and 30.21 mg/g) compared to amino acid of Soya bean meal (1.05 and 25.85 mg/g). Hens fed 20% CM with or without 2% clay recorded the lowest significant final body weight and body weight change (1589.00, 1593.33 and 69.33, 74.00 g), respectively. Hen fed 15% CM with 2% clay recorded higher egg production and egg mas (81.54% and 46.72 g/hen/day). Hens fed 20% CM without clay recorded the highest feed consumption value (111.6 g/hen/day). While, the control group recorded the best feed conversion ratio (2.39 g feed/g egg) followed by the group fed 15% with 2% clay (2.61 g feed/g egg). Hens fed diet containing 15% CM with 2% clay recorded the highest relative weight of yolk (22.01%). However hens fed 20% CM with 2% clay recorded the lowest value of yolk index (45.99%) and yolk color (7.80). Alanine transaminase (ALT) was increased significantly in hens fed 20% without or with 2% clay (41.00 and 39.33 I.U.L.). While, ALT was decreased (p≤0.05) in hens fed 10 and 15 % CM with 2% clay (24.33 and 25.00 I.U.L.). The results indicated that 15% CM with 2% clay in laying hen diets improved significantly egg production, egg mass, egg quality, digestion coefficients, blood characteristics, economic efficiency and relative economic efficiency under desert condition.