TILAPIA GROWTH PERFORMANCE USING PROTEASES AND CARBOHYDRASES

Ten practical tilapia diets were formulated to contain 32% protein and 6% lipids. Six diets were formulated to contain low level of fiber (LF) and included free protease (FP), protected protease (PP), free carbohydrase (FC), protected carbohydrase (PC), and a mix of free protease and carbohydrase (MFPFC). Four diets were formulated to contained high fiber (HF) and included dried distillers grains as a source of fiber and reduced protein digestibility. Treatments included a basal diet and a basal diet supplemented with free protease (FP), free carbohydrase (FC), and a mix of free protease and free carbohydrase (MFPFC). The level in the diet of free protease (FP) and protected (PP) was 175 g per metric ton, the level of free carbohydrase (FC), protected carbohydrase (PC) and the mix of free protease and carbohydrase (MFPFC) was 125 g per metric ton. The diets were offered to juvenile tilapia (9.29 g initial mean weight) over a 10-week growth trial. Four replicate groups of 20 fish/aquaria were offered the test diets at near satiation levels. At the conclusion of the growth trial, survival was near 100% and weight gain was around 1000%.  In general, fish maintained on the high fiber diet performed slightly poorer than those on the lower fiber diet. Concerning enzyme supplements, there were no clear statistical differences among the treatments. When considering planned comparisons, there were some significant differences or possible trends in final weight and feed efficiency. Overall, there were no clear advantages detected to the protected enzymes.