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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.
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.
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
(Stephen-Hassard and Tacon, in press).
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.
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