鱼类养殖业的关键是饲料。战后,世界淡水渔业有了长足的进步,1950年鱼产量仅240万吨,近年来已达到760多万吨。在增产的诸因素中,首推饲料,特别是配合饲料在生产中的应用和推广。美国自1958年鳟鱼颗粒饲料研究成功并投放市场,把生产一斤鳟鱼的成本降到0.17美元,从而大大刺激了鳟鱼养殖业的发展,五十年代鳟鱼年产不过180～270万斤,六十年代末即发展到近2,000 The key to fish farming is feed. After the war, the world's freshwater fisheries have made great strides. In 1950, the fish production was only 2.4 million tons and in recent years it reached more than 7.6 million tons. Among the factors that increase production, the most important are feed, especially the application and promotion of compound feed in production. The United States has succeeded in bringing trout pellets to market since 1958 and has reduced the cost of producing a pound of trout to $ 0.17, greatly stimulating the development of trout farming. The trout produced in the 1950s was only expected to produce between 1.8 and 2.7 million It grew to almost 2,000 in the late 1960s