Wheat basal diet was control.The tested diets were wheat basal diet added with different level of xylanase(0.05%,0.10%,and 0.15%).Each treatment was devised with 5 repeats and each repeat had 40 male Tilapia nilotica L.All the fishes lived in floating cages were fed 4 times a day and each time were fed to satiation.75 days later the activities of proteinase,amylase,lipase,xylanase,cellulose and pectinase were determined.The results indicated that: The activities of proteinase and cellulose in gaster of the ...