PURPOSE: To obtain a nutrient composition effective for remarkably increasing the accumulation concentration of carotenoid in the biotissue of sea bream, etc., and contributing to the improvement of the production efficiency and the quality of product by compounding L-ascorbic acid glucoside together with carotenoids.

CONSTITUTION: The composition for feeding to young yellowtail, sea bream, salmon, trout, sweetfish, shrimp, crab, carp, goldfish and chicken is produced by compounding (A) carotenoids selected from astaxanthin, β-carotene, zeaxanthin, lutein, salmoxanthin, tunaxanthin, doradexanthin, retinal, halocynthiaxanthin, fucoxanthin, capsanthin, canthaxantin, β-apo-8'-carotenoic acid ethyl ester and their steric isomers with (B) L-ascorbic acid 2-glucoside. The composition is preferably formed in the form of porous pellets with an extruder, etc., at 100-200°C.