Effects of Different Dietary Lipid Levels on the Growth Performance, Body Composition and Digestive Enzymes of the Dog Conch, Laevistrombus canarium

Abstract

A feeding experiment investigated the effects of dietary lipid levels on the growth, muscle composition and digestive enzyme of 0.28 g Laevistrombus canarium. Five semi-purified diets containing 0% (L0), 2% (L2), 4% (L4), 6% (L6), and 12% (L12) lipids were formulated. Each diet was randomly assigned to three replicate groups of L. canarium larvae. The final weight, weight gain percentage and specific growth rate of L. canarium larvae fed with diets L6 and L12 were significantly higher than those of larvae fed with diets L0, L2 and L4. The feed conversion ratio (FCR) of L. canarium larvae fed with treatment diets was significantly lower than that of conch fed with control diet. The minimum dietary n-3 highly unsaturated fatty acid (HUFA) (C20:5n-3 + C22:6n-3) requirement for L. canarium was 19.59% of total lipid. Lipase activity in soft body increased with an increasing dietary lipid level, but amylase activity was not significantly affected by the dietary lipid level. Based on a broken-line of the final weight of L. canarium larvae, the optimum dietary lipid levels were 5.6%.