Effects of dietary piperine supplementation on innate immunity, growth performance, feed utilization and intestinal morphology of olive flounder (Paralichthys olivaceus).

Piperine, the main bioactive component of black pepper (Piper nigrum) or long pepper (Piper longum), has anti-inflammatory, antifungal, and antibacterial properties. This study was carried out to evaluate the supplemental effects of piperine in olive flounder (Paralichthys olivaceus) diets. Six isonitrogenous and isolipidic diets were formulated to contain different levels of piperine at 0.00, 0.25, 0.50, 0.75, 1.00, and 2.00 g/kg (Con, P25, P50, P75, P100, and P200, respectively). Diets were randomly allocated to triplicate groups of fish (initial weight 27.6 ± 0.4 g, 30 fish/tank) and fed three times daily for 8 weeks. Results showed that dietary piperine significantly improved fish growth and feed utilization efficiency. The highest growth, including the highest Igf-1 mRNA expression, was observed in the P50 group, while P50 and P75 groups showed the highest protein efficiency ratio. Compared to the Con group piperine supplemented groups had significantly higher lysozyme activity, immunoglobulin level, and phagocytosis activities. Plasma cholesterol was significantly lower in fish fed P200 diet. Dry matter and protein digestibility were higher in P25, P50, and P75 groups than in Con group. Dietary piperine increased the intestinal villi length and goblet cell counts. In the challenge test against Edwardsiella tarda, all the groups supplemented with piperine showed higher cumulative survival compared to Con group. Therefore, these findings indicate that dietary piperine supplementation can improve growth performance, innate immunity, disease resistance, diet digestibility, and intestinal morphology of olive flounder. The optimum dietary piperine level seems to be approximately 0.5 g/kg for the fish.

Effects of Dietary Fish Meal Replacement with Alternative Protein Ingredients and Their Combinations on Growth Performance, Feed Utilization, Fillet Composition, and Biochemical Parameters of Red Seabream (Pagrus major).

The experiment was conducted to evaluate alternative protein ingredients in a low-fish meal (FM) diet for red seabream (Pagrus major). Twelve experimental diets were formulated. Control diet (CON) was designed to contain 60% FM. Other experimental diets were formulated by replacing 50% of FM from the CON with soy protein concentrate (SPC), corn gluten (CG), meat meal (MM), and/or chicken byproduct meal (CBM). Four diets were designed including one of SPC, CG, MM, or CBM as FM replacer and designated as SPC, CG, MM, and CBM. Six other diets were formulated by adding two ingredients as SPC and CG, SPC and MM, SPC and CBM, CG and MM, CG and CBM, or MM and CBM, and designated as SCG, SMM, SCM, CMM, CCM, and MCM, respectively. The 12th diet (MIX) was formulated by including SPC, CGM, MM, and CBM. Triplicate fish groups (50.2 ± 0.1 g) were hand-fed for 12 weeks. Weight gain (WG) of fish was significantly improved by MM and MCM diets compared to CG, SCG, CMM, and CCM diets. WG of CON, SPC, CM, SMM, SCM, and MIX groups were comparable with MM and MCM groups. The lowest WG was observed in CG and CMM groups. Feed efficiency (FE) was significantly higher in MM group compared to SPC, CG, SGC, and CMC groups. FE of MCM group was significantly higher than CG and SCG groups. Fillet linolenic acid (C18:2n-6) level in CG group was significantly higher than CON, MM, CM, SCM, CCM, and MCM groups. Serum lysozyme activity was significantly higher in MCM and MIX groups. Therefore, a high level of dietary CG reduces the growth performance and feed utilization of red seabream. A mixture of MM and CBM seems to be more efficient in replacing FM from red seabream diet.