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首页> 外文期刊>ICES Journal of Marine Science >Nutrition in cod (Gadus morhua) larvae and juveniles
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Nutrition in cod (Gadus morhua) larvae and juveniles

机译：鳕鱼（幼体和幼鱼）的营养

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Over the past few years, great progress has been made in culturing cod larvae in indoor hatcheries using rotifers and Artemia or formulated feed as start-feed (intensive systems). However, when compared with natural systems based on copepods grown in seawater lagoons, the growth potential has not been fulfilled, and deformities of larvae and juveniles increase production costs. The deformities, which are seldom seen in natural systems, also constitute an ethical problem. The differences in growth and development of deformities in intensive and natural systems may be dependent, in part, on nutrition, but are caused by environmental conditions and early husbandry practises as well. To identify nutrients that may be deficient or in excess in live feed, we are in the process of screening the nutrient compositions of rotifers and Artemia grown or enriched on different feeds and comparing them with the composition of copepods and published requirements for larger fish. Replacing live food with formulated diets as early as possible is a goal of marine larval aquaculture. It is important that these diets contain protein which is available for the larvae and phospholipids that promote the absorption and transport of fat. The optimum macronutrient composition in diets for cod juveniles has been determined and can be extrapolated, with caution, to the larval stage. A problem in using formulated diets is the extensive leakage of nutrients as a result of the large surface area to volume and the short diffusion distance in the microparticles. Leakage leads to rapid loss of small, water-soluble molecules such as free amino acids, vitamins, and minerals, but extensive leakage of water-soluble protein has also been shown. The demand for protein available to the larvae, which probably will make the protein more water soluble, is therefore in conflict with the need to reduce protein leakage from the feeds. Development of feed production technology to prevent nutrient leakage is essential in order to make formulated diets a good alternative to live feed.
机译：在过去的几年中，在室内孵化场中使用轮虫和卤虫或配制饲料作为起始饲料（集约化系统）在养殖鳕鱼幼虫方面取得了巨大进展。但是，与基于在海水泻湖中生长的co足类的自然系统相比，其增长潜力尚未得到满足，幼虫和幼体的畸形增加了生产成本。在自然系统中很少见到的畸形也构成了道德问题。集约化和自然系统中畸形的生长和发育差异可能部分取决于营养，但也由环境条件和早期饲养管理造成。为了确定活饲料中可能缺乏或过量的营养素，我们正在筛选在不同饲料上生长或富集的轮虫和卤虫的营养成分，并将其与co足类的成分和已发表的对大鱼的需求进行比较。尽早用配方饮食代替活食品是海洋幼体水产养殖的目标。重要的是，这些饮食应含有可用于幼虫的蛋白质和促进脂肪吸收和运输的磷脂。确定了鳕鱼幼鱼日粮中最佳的常量营养素组成，可以谨慎地推断到幼体阶段。使用配方饮食的一个问题是由于大的表面积体积和微粒中的短扩散距离导致营养物质大量泄漏。泄漏会导致水溶性小分子（例如游离氨基酸，维生素和矿物质）迅速流失，但水溶性蛋白也大量泄漏。因此，对幼虫可用蛋白质的需求可能会使蛋白质更易溶于水，因此与减少饲料中蛋白质泄漏的需求相矛盾。饲料生产技术的发展对防止营养物质的泄漏至关重要，以使配方饲料成为活饲料的良好替代品。

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