Effects of replacing dietary shrimp meal and soybean meal with silkworm (Bombyx mori) pupae meal on growth performance of rainbow trout Oncorhynchus mykiss

Shrimp and soybean meal are important and expensive protein sources for rainbow trout ( Oncorhynchus mykiss ) in Nepal. During the 90-day trial, this study examined the effects of replacing shrimp meal (SM) and full-fat soybean meal (FFS) with varied levels of spent silkworm ( Bombyx mori ) pupae meal (SPM) on growth performance, feed conversion ratio, and survival. Four treatment groups were examined for the experiment: T 1 : 0% SPM, T 2 : 12.5% SPM, T 3 : 25% SPM, and T 4 : 37.5% SPM. Three replicates of 125 fish (2.5±0.2 g) were used for each treatment group. As SPM rose in the diet, final weight, weight gain, specific growth rates, and daily growth rates increased significantly ( p< 0.05). Experimental diets had no effects on condition factors, feed conversion ratios, and survival. In conclusion, SPM can replace SM and FFS up to 35.7% in rainbow trout diets without affecting growth and feed utilization.