Studies on the Lipid Levels of Newly Developed Dry Pellets for Sea Fish and the Prevention of in vivo Lipid Peroxidation

本研究旨在开发一种低不饱和度的黄尾鱼软干颗粒（SDP），以减少由于体内脂质过氧化进展而导致的各种鱼类疾病的发生，并提高养殖鱼的品质。将沙丁鱼油和棕榈油按1:0（饲料1）、1:1（饲料2）和1:2（饲料3）的比例混合，制备3种不同不饱和程度的sdp。体重分别为83g和116g的黄尾鱼幼鱼用这些sdp饲喂两个月。饲料1和饲料2的平均体重显著高于饲料3。饲料2和3的血浆TBA值和组织脂质含量均低于饲料1。肌肉注射苯肼后，鱼饲料中血浆胆红素含量高。此外，接种黄疸棒状菌后，饲料3中TBA值和胆红素含量最高。上述结果表明，以1:1的棕榈油替代沙丁鱼油可提高黄尾鱼的SDP水平。

This study was conducted to develop a soft dry pellet (SDP )with a low unsaturation for yellowtail in order to reduce the occurrence of various fish diseases due to in vivo lipid peroxidation progression as well as to improve the quality of the cultured fish. Three kinds of SDPs with different levels of unsaturation were prepared by mixing sardine oil and palm oil in ratios of 1 : 0 (diet 1), 1 : 1 (diet 2), and 1 : 2 (diet 3). Juvenile yellowtail weighing 83g or 116g were fed for two month on these SDPs. The average body weights of fish fed diets 1 and 2 were quite higher than that of fish on diet 3. Plasma TBA values and tissue lipid contents of fish fed diets 2 and 3 were lower than that of fish diet 1. After an intramuscular injection of phenylhydrazine, high plasma bilirubin content was observed in fish fed diet 3. Moreover, after the inoculation of rod-shaped bacteria causing jaundice, the highest TBA value and bilirubin content were observed in fish fed diet 3. These results suggest that replacement of sardine oil by palm oil in ratio of 1 : 1 as the dietary lipid may enable in the SDP for yellowtail.