This study aims to investigate the effect of different dietary lipid levels on the growth performance, fatty acids and their relative enzymes, and expression of peroxisome proliferator‐activated receptor α (PPARα), leptin, and adiponectin genes in juvenile genetic improvement farmed tilapia (GIFT, Oreochromis niloticus). Six groups of the juveniles with 40 d of age in triplicate are fed for 90 d using six iso‐nitrogen (34 g/100 g dietary protein) diets with different lipid levels: 0.35 (control), 3.35, 6.35, 9.35, 12.35, and 15.35 g/100 g adjusted by adding fish oil. It is concluded that the greatest effect is found in the diet with 9.35 g/100 g of lipid, which is the optimal dietary lipid in the experiment and can be applied in developing the optimal diet for juvenile GIFT tilapia to promote the development of tilapia aquaculture industry.
Practical Applications: It is found that the diets with lipid supplementation can significantly influence the expression of PPARα, leptin, and adiponectin genes of juvenile GIFT tilapia and recognized that dietary lipid supplementation can significantly affect their growth performance, fatty acids, and relative enzymes. The greatest effect is found in the diet with 9.35 g/100 g of lipid, which is the optimal dietary lipid in the experiment. The findings can be applied in developing the optimal diet for juvenile GIFT tilapia, which will promote considerably the development of tilapia aquaculture industry.