Abstract:

Pangas catfish, Pangasius hypophthalmus is one of the most widely cultured fish species in Asia. The growth and flesh quality of fish depend largely on the quality and composition of feed. Inclusion of exogenous enzyme can improve the palatbility and digestibility of feed. However, there is a lack of research on the use of exogenous enzymes in fish diet for improved growth and nutritional quality of fish. Thus, in the current study, the effects of enzyme inclusion in fish diet were evaluated using pangas catfish as an experimental animal. The study was conducted in a laboratory condition with a flow-through system where 12 plastic tanks with 750 L water capacity were used where the tanks were grouped randomly. Each tank was stocked with 15 fingerlings of pangas catfish. Three different concentrations (3, 4 and 5% of the total feed) of Zymex, a commercially available ulti-enzyme were used for treatment groups along with a control group with no enzyme supplementation. The length-weight relationship of the experimental fish using the initial and final data was established where a significantly positive relationship was found (P<0.05). Growth performance including condition factor, specific growth rate and feed conversion ratio was significantly improved by 3% enzyme supplementation (P<0.05). Average daily gain did not vary significantly between treatments. Three percent enzyme supplementation in the diet significantly increased crude protein and lipid contents and reduced moisture content (P<0.05). Significantly higher ash content was found in fish fed both 3 and 5% enzyme contained diet (P<0.05). In case of body indices, 5% enzyme supplementation provided significantly higher viscerosomatic index (P<0.05) while 3% provided significantly higher flesh yield (P<0.05). However, hepatosomatic index did not vary significantly between treatments. From the findings it is concluded that enzyme supplementation at 3% of the diet can improve the growth performance and nutritional quality of pangas catfish.

Keywords: