Determination of Dietary Pantothenic Acid Requirement for Olive Flounder (Paralichthys olivaceus): Growth and Physiological Responses.

This study investigated the dietary requirement of pantothenic acid (PA) and its effects on growth, feed efficiency, liver health, β-oxidation, hematological parameters and immune and antioxidant responses in olive flounder (Paralichthys olivaceus). A basal diet (P0) was formulated without PA supplementation, and six additional diets were prepared by adding 10, 20, 30, 40, 50 or 60 mg/kg PA (designated as P10-P60). Juvenile P. olivaceus (initial mean body weight: 45.0 ± 0.01 g) were randomly distributed into 21 tanks and fed the diets twice daily for 12 weeks. Growth performance and feed efficiency were significantly higher (P < 0.05) in P10 and P20 groups than in P0 group. Liver lipid levels were significantly lower (P < 0.05) in all PA-supplemented groups, while hepatic PA, CoA concentration, β-oxidation activity and levels of docosahexaenoic acid and α-linolenic acid were significantly higher (P < 0.001) compared to P0 group. Dietary PA supplementation reduced aspartate aminotransferase and alanine aminotransferase activities, though activities of both enzymes increased at higher PA supplementation levels. Lysozyme and anti-protease activities were significantly higher in P10 and P20 groups, and immunoglobulin levels were elevated in P10 group compared with P0 group. Glutathione peroxidase activity increased significantly in P10, P20 and P40 groups, while superoxide dismutase activity increased in P10, P20, P50 and P60 groups (P < 0.05). Broken-line regression analysis based on weight gain and feed efficiency indicated that the optimal dietary PA requirement for P. olivaceus is 18.8 mg/kg.