Growth experiment of juvenile red sea bream Pagrus major fed low or non-fish meal diets formulated with black soldier fly Hermetia illucens meal

This study examined the use of defatted black soldier fly Hermetia illucens (BSF) meal as a fish meal substitute at high dose. Six-week feeding trials were conducted on juvenile red sea bream Pagrus major using experimental diets in which half or all of the fish meal in the control diet was substituted with defatted BSF larvae or prepupae meal. The larvae-fed groups showed higher feed efficiency, apparent protein retention and apparent fat retention than the control group. The group fed the diet containing younger larvae tended to have higher feed efficiency, apparent nutrient retention and apparent digestibility of protein and fat compared to fish fed aged larvae. However, daily feed intake was lower in several larvae-fed groups than in the control group. Lower concentration of total protein, blood urea nitrogen and total cholesterol in the plasma was observed in the larvae-fed groups than in the control group.