A growing business

Although aquaculture dates from the earliest parts of human history in Asia, Europe and in the Pacific Islands, it is only in the last few decades that the sector has begun to catch up with the rest of animal agriculture in terms of the science of feed milling and nutrition. Despite this, aquaculture currently represents the fastest growing segment of agriculture and the animal feed milling industry, particularly in China and the Asian region where over 90% of global aquaculture production is currently realized.

Ingredients

A very wide range of ingredients are used to prepare aquafeeds. Feeds range from single component feeds available on-farm such as grass or rice bran to farm-made formulated feeds and commercial feeds. They include aquatic and terrestrial plants (duckweeds, azolla, water hyacinth etc.), aquatic animals (snails, clams etc.) and terrestrial-based live feeds (silkworm larvae, maggots etc.), plant processing products (de-oiled cakes and meals, beans, grains and brans) and animal-processing by-products (blood and feather meal, bone meal etc.). Formulated commercial feeds are composed of several ingredients, mixed in various proportions to complement each other and form a nutritionally complete diet.

Farm-made and commercial aquafeeds can be fairly easily split depending on whether they are primarily intended for farm use or for commercial sale. Also, while raw materials that are high in moisture and only of local and/or seasonal availability may be used in the preparation of farm-made aquafeeds, commercial fish feed manufacture is predominantly associated with the processing of dry ingredients and the manufacture of a dry product.

Processing

Using a feeding tray helps the fisher assess how well the shrimp are feeding

FAO/20312/J.Spaull

The most common aquafeed processing operations can be summarized as raw material size reduction, raw material blending, feed forming, and feed drying. For these processes many and various options of processing equipment are available ranging from simple mortar and pestle to mincers, hammer mills, pelleters, and extruders.

Commercial aquafeed manufacture presents special challenges to the traditional feed milling concepts due to the size and variety of animals being cultivated. Moreover, feed for aquatic species requires a higher degree of precision be it the generally finer particle size of ingredients, or the precise mixing of as many as four dozen ingredients into a feed pellet of minute size in comparison to its terrestrial counterpart. These are the compelling reasons why many new aquaculture feed mills are dedicated to produce only aquatic feeds and often employ human food standards in production. Along with the higher standards of production come more expensive and higher quality standards for the ingredients used for what are often very sensitive production animals.
 
Farm-made aquafeeds

There is a lack of an exact definition for farm-made aquafeeds. FAO have suggested that farm-made feeds be defined as feeds in pellet or other forms, consisting of one or more artificial and/or natural feedstuffs, produced for the exclusive use of a particular farming activity and not for commercial sale or profit.