Effects of Dietary Fiber and Its Optimum Levels for Growth of Hybrid Clarias Catfish (Clarias macrocephalus x Clarias gariepinus)

Abstract

Six isonitrogenous (37.0% protein) and isocaloric (2.8 Kcal digestible energy/g) diets were formulated to contain 0, 3.0, 6.0, 9.0 and 12.0% rice hull (diets 1 - 5) and 12.0% cellulose (diet 6). The formulated diets were used for determination the effects of dietary fiber and its optimum levels for growth and diet utilization of hybrid Clarias catfish. The diets were fully fed to juvenile (2.5 g) and young (58.0 g) hybrid Clarias catfish held in 120 - L glass aquaria twice daily for eight weeks. The study showed that dietary fiber up to 12.0% (10% crude fiber) had no adverse effect on growth, survival and diet utilization of juvenile and young fish. However, there was trend for maximum growth and diet utilization in juvenile fish fed diets containing 6.0-12.0% rice hull (3.5 - 6.5% crude fiber) and in young catfish fed 9.0 - 12.0% rice hull (5.0 - 6.5% crude fiber). The dietary fiber at the levels used in this study had no effect on intestinal length, stomach weight and hepatosomatic index of the experimental fish. However, juvenile fish fed diet containing 12.0% cellulose deficated more fecal materials than that of fish fed the other diets.