Growth Response and Flesh Quality of Common Carp, Cyprinus carpio Fed with High Levels of Nondefatted Silkworm Pupae

Abstract

Nondefatted silkworm pupae, a major by-product of the sericulture industry in India is rich in protein and fat. A growth trial was conducted over a period of 90 days to study the usefulness of pupae as a source of protein and energy in the diet of common carp, Cyprinus carpio. Results indicated that the pupae could be used to completely replace fishmeal and could be included up to 50% in the diet. There was no significant difference in the final weight gain, food conversion ratio, and protein efficiency ratio of fish fed with fishmeal based control diet and diets incorporated with 30, 40 or 50% pupae. However, the net protein retention was found to increase with increasing levels of pupae in the diet. Ribonucleic acid/deoxyribonucleic acid (RNA/DNA) ratio was highest in fish fed 50% pupae. Protein deposition in the carcass increased, while fat content decreased as pupae content in the diet increased. Protease enzyme activity was higher in pupae fed fish. Organoleptic evaluation of the fish indicated no significant difference between any of the treatments, either in the overall quality or individual attributes such as odor, texture, and flavor implying that pupae can be safely used up to 50% without hampering the growth and meat quality.