Now showing items 1-3 of 3

    • Article

      Dietary soy peptide enhances thermotolerance and survival of juvenile japanese flounder, Paralichthys olivaceus 

      JA Ragaza, REP Mamauag, S Yokoyama, M Ishikawa & S Koshio - Journal of the World Aquaculture Society, 2015 - World Aquaculture Society
      Soy peptide (SP), a soy protein enzymatic hydrolysate, contains bioactive substances that could be utilized as an immune-stimulating feed ingredient. The experiment evaluated the efficacy of dietary SP on promoting growth, and enhancing tolerance and survival to heat stress in juvenile Japanese flounder, Paralichthys olivaceus. Four diets were incorporated with different levels of SP (0, 2, 5, and 10%) and a 6-wk feeding trial ensued. Following the feeding trial, the experimental groups were subjected to heat stress to measure survival rate and heat shock protein 70s (HSP70s) in gill, liver, and skin. Fish fed diets with SP inclusion showed considerable decrease in percent weight gain. Significantly higher lethal time values to 50% mortality (LT50) value were recorded for fish fed 10% SP. Moreover, LT50 values of fish fed 2 and 5% SP were significantly higher compared with fish fed control diet. HSP70s produced in all the tissues were significantly highest in fish fed 10% SP. HSP70s values were significantly higher in fish fed 2 and 5% SP compared with fish fed control diet. A significant reduction in HSP70s among all groups during recovery period was also observed. These results suggest that SP can be used to enhance the immune response and survival of P. olivaceus under heat stress.
    • Article

      Dietary supplemental effects of red seaweed Eucheuma denticulatum on growth performance, carcass composition and blood chemistry of juvenile Japanese flounder, Paralichthys olivaceus 

      JA Ragaza, S Koshio, RE Mamauag, M Ishikawa, S Yokoyama & SS Villamor - Aquaculture Research, 2015 - Wiley
      A 56-day feeding trial was conducted to determine the effects of supplementing diets of juvenile Japanese flounder, Paralichthys olivaceus, with Eucheuma denticulatum (EDP). Isonitrogenous and isolipidic test diets were prepared using a fishmeal-based positive control diet (PC) and a fishmeal-soy protein concentrate negative control diet (NC) supplemented with 3 (D3%), 6 (D6%) and 9% (D9%) EDP. The test diets were assigned to tanks (12 fish tank−1, initial mean body weight of 0.42 ± 0.01 g) in triplicates. Results of the feeding trial indicated that growth rates and feed efficiency significantly improved (P < 0.05) when 3% EDP was supplemented in the diets. However, there was a significant reduction (P < 0.05) of growth and feed efficiency in fish fed diets with higher supplementation levels. Protein, lipid, dry matter and ash contents of carcass and their corresponding nutrient retention values were not markedly altered in all dietary treatments. Fish fed diets supplemented with EDP exhibited higher (P < 0.05) omega-3 polyunsaturated fatty acid accumulation in dorsal muscle when compared with those of fish fed NC. Blood chemical parameters showed significant differences (P < 0.05) in total cholesterol and triglyceride levels. These results suggest that EDP can be efficiently utilized by Japanese flounder and can promote best growth and feed utilization at a level of 3%.
    • Conference paper

      Status of development and use of alternative dietary ingredients in aquaculture feed formulations in Japan: Recent progress of fish meal replacement study of marine fish 

      S Koshio - In MR Catacutan, RM Coloso & BO Acosta (Eds.), Development and Use of Alternative Dietary Ingredients or Fish Meal Substitutes in Aquaculture Feed Formulation … Ingredients or Fish Meal Substitutes in Aquaculture Feed Formulation, 9-11 December 2014, Nay Pyi Taw, Myanmar, 2015 - Aquaculture Department, Southeast Asian Fisheries Development Center
      Fish meal (FM) reduction in aquafeeds is one of the most important issues in aquaculture in Japan. The progress in research studies on reducing the amount of FM in aquafeeds has been demonstrated in several marine species in recent years. This report summarizes those on three species which are high-valued and intensively cultured in Japan; namely, the red sea bream, the amber jack and the Kuruma shrimp.