Effects of Dietary β‐1,3 Glucan and Feed Stimulants in Juvenile Olive Flounder, Paralichthys olivaceus

Abstract

Abstract.— The present study was conducted to investigate the effects of dietary supplementation of β‐1,3 glucan and a laboratory developed feed stimulant, BAISM, as feed additives for juvenile olive flounder, Paralichthys olivaceus. Eight experimental diets were formulated to be isonitrogenous and isocaloric and to contain 50.0% crude protein and 16.4 kJ of available energy/g with or without dietary β‐1,3 glucan and BAISM supplementation. β‐1,3 glucan (G) and BAISM (B) were provided at 0% in the control diet (G0B0) and at 0.05% G + 0.45% B (G0.05B0.45), 0.05% G + 0.95% B (G0.05B0.95), 0.1% G + 0.90% B (G0.1B0.9), 0.10% G + 1.90% B (G0.1B1.9), 0.15% G + 1.35% B (G0.15B1.35), 0.15% G + 2.85% B (G0.15B2.85), and 0.30% G + 2.70% B (G0.3B2.7) in experimental diets. After the feeding trial, fish fed G0.1B0.9, G0.1B1.9, and G0.15B1.35 diets had higher percent weight gain (WG), feed efficiency ratio (FER), specific growth rate (SGR), protein efficiency ratio (PER), and condition factor (CF) than those fed G0B0, G0.05B0.45, G0.05B0.95, G0.15B2.85, and G0.3B2.7 diets (P < 0.05); however, there was no significant differences among fish fed G0.1B0.9, G0.1B1.9, and G0.15B1.35 diets. Fish fed G0.1B0.9 and G0.1B1.9 diets had higher chemiluminescent responses (CL) than those fed the other diets (P < 0.05). Lysozyme activity of fish fed G0.1B0.9 diet was significantly higher than that of fish fed the other diets (P < 0.05). These results indicated that the optimum dietary supplementation level of β‐1,3 glucan and BAISM could be approximately 0.10% β‐1,3 glucan + 0.90% BAISM (G0.1B0.9) of diet based on WG, FER, SGR, PER, CF, CL, and lysozyme activity in juvenile olive flounder, P. olivaceus.

Evaluation of different dietary additives based on growth performance, innate immunity and disease resistance in juvenile Amur catfish, Silurus asotus

“…BG) compared with Yucca meal (YM), b-glucan (BG) and control (CONT) diets. The additives, b-glucan and Yucca meal have already shown their immunostimulating effects on fish (Yoo et al 2007;Njagi et al 2017). In this study, the results demonstrated the potential effect of a mineral-based additive such as Song-gang Ò stone in the juvenile Amur catfish.…”

“…BG) ( Table 2). The supplementations of the additives are based on our previous research findings (Yoo et al 2007;Njagi et al 2017;Won et al 2017). The unit price of SG, YM and BG is US$ 0.89/kg, US$ 15.21/kg, US$ 26.84/kg, respectively; and the price contribution for the unit kg of feed of SG, YM and BG is US 0.04 cents (¢), US 0.08 cents (¢), 1.34 cents (¢) and US 1.7 cents (¢), respectively.…”

“…The observations with the SG diet is comparable to the findings by Lee et al (2015b) and Won et al (2017) with Song-gang Ò stone and yellow loess, respectively, in rainbow trout Oncorhynchus mykiss as well as Shahkar et al (2015) with Macsumsuk Ò in Nile tilapia Oreochromis niloticus. Growth and feed efficiency improved in olive flounder Paralichthys olivaceus fed a combination of b-glucan and BAISM-contained diets (Yoo et al 2007). Measurement and analysis of condition factor (CF), hepatosomatic index (HSI) and viscerosomatic index (VSI) are important in assessing food value in an animal, its health status and general well-being as well as the degree of pollutants in the environment where the animal lives (Ighwela et al 2014).…”

“…It influences non-specific or innate immune responses such as increased lysozyme production and superoxide anion production in activated macrophages, thereby, reducing fish mortality when exposed to pathogens (NRC 2011). Low doses of b-glucan have been suggested to enhance growth and innate immunity in different cultured fish species (Ai et al 2007;Yoo et al 2007;Das et al 2013;Sirimanapong et al 2015).…”

“…It is the second freshwater farmed fish species with a production of 4607 tons in the Republic of Korea in 2014(FAO 2016. Several dietary additives have been identified to promote growth and immune responses in the aquaculture industry (Choi et al 2004;Ai et al 2007;Yoo et al 2007;NRC 2011;Güroy et al 2014;Lee et al 2015b;Shahkar et al 2015); however, each dietary additive could produce different levels of responses in individual fish species and contribute differently to feed cost. In this regard, the effects of dietary additives from mineral sources have not yet been investigated in Amur catfish.…”