Comparison on efficacy of hybrid Clarias catfish diets formulated from nutrient requirement data to a selected commercial catfish feed: Technical paper No. 179

Two experiments were performed to compare the efficacy of hybrid Clarias catfish diets developed base on nutrient requirement data to a selected commercial catfish feed. Experiment 1 was to select the best of four commercial catfish feeds (COM 1-COM 4) by determination the protein digestibility of those feeds as well as fish performance. Hybrid Clarias catfish (15.7 g each) were randomly stocked in 12 digestibility tanks at rate of 10 fish per tank and fed to apparent satiation once daily for 2 weeks. Protein digestibility of all feeds were averaging 95 percent and were not significant different (P0.05) among dietary treatments However, fish fed COM 2 had best performance. COM 2 was, therefore, selected to compare its efficacy with 10 formulated diets (diets 1-10) in experiment 2. Diets 1-10 developed from conventional feedstuffs base on nutrient requirement data for hybrid Clarias catfish. Diets 1-4, 5-8, 9 and 10 composed of Danish fishmeal, Thai fishmeal, chicken head and trash fish as animal protein sources, respectively. Protein contents of diets 1, 2, 5, 6 and 3, 4, 7, 8 and 10 were 35 percent and 32 percent, respectively. Two digestible energy levels; 330 and 290 kcal/100 g were assigned for diets 1, 2, 5, 6, 9 and 3, 4, 7, 8, 10, respectively. The formulated diets and COM 2 were fed to apparent satiation twice daily for 8 weeks to 5-6 g fish stocked in 33 glass aquaria at rate of 15 fish per aquarium. It was concluded that weight gain of fish fed diets 1-10 were better than that of fish fed COM 2 (P0.05). Diet 9 contained too high energy (356 kcal/100 g) and reduced feed consumption of fish. Diet utilization were lower for fish fed diets contained Thai fishmeal (diets 5-8) than for fish fed diets contained Danish fishmeal or trash fish (diets 1, 2, 3 and 10) (P 0.05). Danish fishmeal containing diets with 35 percent protein (diets 1 and 2) produced better weight gain than did 32 percent protein diets (diets 3 and 4) with same energy level. Energy levels at certain protein level had little effect on fish growth. However, fish fed 32 percent protein diet with 330 kcal/100 g (diet 3) grew and utilized diet as well as those fed 35 percent protein diet with 290 kcal/100 g (diet 2). The study suggests that diets 1, 2, 3 and 10 were suitable for promoting fish growth and diet utilization. If a less fatty fish is desirable, diets 2 and 10 are prefered. However, diets 1, 3 and 10 are recommended to fish farmers to attain low feeding cost.