Effect of deoiled silkworm pupae meal (Bombyx mori) as a replacement of fish meal in the diet of juveniles of Silver pompano, Trachinotus blochii

Abstract

Abstract A ninety days growth trial and four weeks of digestibility study were conducted to evaluate the effect of replacing fish meal (FM) with deoiled silkworm pupae meal (DSWP) in the diet of juvenile silver pompano. Silver pompano seeds (0.93 ± 0.07 g) were randomly distributed into 15 FRP tanks (120 × 55 × 38cm) each consisting of 20 fish. Fish were fed thrice a day until apparent satiation with five experimental diets (RD, 25FMODSWP, 50FMODSWP, 75FMODSWP and 100 FMODSWP) which was prepared by replacing fishmeal at 0, 25, 50, 75 and 100% with DSWP respectively. The replacement of fishmeal with DSWP at 25% (p < 0.05) improved the final body weight, specific growth rate, feed conversion ratio and protein efficiency ratio. Apparent digestibility coefficient (ADCs) values of crude protein and fat was found to be higher in the RD and 25FMODSWP groups. Protease activity was significantly (p < 0.05) higher in fish fed the 25FMODSWP diet while amylase and lipase activities were higher in the 75FMODSWP and 100FMODSWP, respectively. The replacement of fishmeal by 75FMODSWP resulted in lower (p < 0.05) fat deposition in the whole-body tissue. The dietary inclusion of DSWP significantly (p < 0.05) improved overall blood profile until 50% FM protein replacement. The replacement of fishmeal with DSWP beyond 50% affects the intestinal structure due to necrotic lesions in the microvilli and detachment of surface epithelial cells from lamina propria. The results of this study suggested that DSWP can be used to replace 30.5% of FM protein which accounts 9.5% of SWP in the diet of silver pompano without any adverse effect on fish.