The present work was conducted to evaluate the effect of concurrent use of probiotic and protease enzyme in commercial layers fed ration with either normal or low crude protein content. One hundred and twenty, 40-week-old apparently healthy Lohman commercial laying chickens were used. Birds were divided into six equal groups (20 each). Group 1 was fed a balanced ration only and kept as control group. Group 2 was fed
the balanced ration mixed with a protease enzyme (0.5 kg/ton feed). Group 3 was fed ration with crude protein 15.73% and mixed with a protease enzyme (0.5 kg/ton feed). Group 4 was fed the balanced ration mixed with a probiotic (0.5 kg/ton feed). Group 5 was fed the balanced ration mixed with a combination of protease enzyme
(0.5 kg/ton feed) and probiotic (0.5 kg/ton feed). Group 6 was fed a ration with crude protein 15.73% and mixed with a combination of protease enzyme (0.5 kg/ton feed) and probiotic (0.5 kg/ton feed). The experimental period was five successive weeks (from 40 to 45-week-old). Groups 2, 4, 5 and 6 showed a significant increase of production parameters (egg laying rate, average egg weight and feed conversion per eggs), serum total protein, albumin and globulin when compared with control group. Probiotic treated groups (4, 5 and 6) showed a significant improvement in serum lipid profile and carcass quality parameters. It could be concluded that the combination of protease and probiotic allows poultry producers to use feeds formulated with protein and amino acids that are 7.5% lower than the recommended industrial standards. This combination not only with no sacrifice in bird performance but also with higher quantity and quality performance. Therefore, this combination is a potential to increase the producers profit.