Effect of Various Sources of Dietary Additives on Growth, Body Composition, and 1 Challenge Test Survival of Juvenile Rockfish Sebastes schlegeli

摘要

Whether the inclusion of the various sources of commercially available dietary additives [ginger (GG), cheonggukjang (CJ), blueberry (BB), persimmon (PM), tomato (TT), broccoli (BC) and yacon (YC)] has an effect on growth, body composition, and challenge test survival of juvenile rockfish Sebastes schlegeli was investigated. Twenty-four groups of 70 fish (1680 in total) were each fed one of eight experimental diets: a control diet (Con) without additives, and diets containing GG, CJ, BB, PM, TT, BC or YC. Fish were hand-fed to satiation twice daily for 7 weeks. At the end of this period, 20 fish from each tank were infected with Streptococcus parauberis and monitored for 10 days. Fish fed the YC diet had greater weight gain compared with fish fed the other diets. Feed efficiency and protein efficiency ratio of fish fed the TT and YC diets were higher than of fish fed other diets. Cumulative mortality of fish fed the GG, BB, and YC diets was lower than of fish fed the other diets on day 5 post infection. We conclude that yacon was the best dietary additive for improving rockfish weight gain, while ginger, blueberry, and yacon effectively lowered mortality of rockfish infected with S. parauberis.