Black Soldier Fly Oil in Different Lipid Diets Could Regulate Tissue Lipid Metabolism and Fatty Acid Composition of Juvenile Mirror Carp

In the present study, our aim was to assess the effect of dietary black soldier fly oil (BSFO) with different lipid contents on the growth performance, body composition, lipid metabolism, and related gene expression in juvenile mirror carp (Cyprinus carpio var. specularis). An 8-week feeding trial was conducted using four isonitrogenous diets (32.0% crude protein) containing two lipid levels: 6% (control (CT) group) and 9% (high lipid (HL) group), both using soybean oil as the oil source. The other two diets contained BSFO on the basis of 6% and 9% lipid, referred to as (CT + BSFO) and (HL + BSFO) groups. The results showed that final body weight, weight gain rate, specific growth rate, protein retention ratio, and feed utilization were significantly increased by using higher dietary lipid levels (P