Page 7 - New additives and ingredients in the formulation of aquafeeds

Preface Aquaculture is a young sector which has been showing in recent years
an unstoppable, exponential and irreversible growth. This trend can only
continue as long as the supply of certain raw materials like fish oils and
meals, which are essential for the manufacturing of feed, may grow in line
with it. This is the only bottleneck for the future of aquaculture: fish oil
production is at a standstill. The massive and traditional sources of fish oil
have been based and in fact, they are still supported by the exploitation
of great biomass of marine species. These and many other fisheries are
nowadays technically declining and socially under question.
Fish meals and oils go through the same processing; both depend highly on
wild fisheries as Peruvian anchovy (Engraulis ringens) which are under a high
fishing pressure. This situation together with other new phenomenon like
climatic change could explain its stagnation or even recession. This would be
completely negative for the aquaculture sector whose needs of fish oil for
year 2030 are estimated at 40 million tonnes.
To consolidate the desired and rapid growth, aquaculture should base its
expansion in a greater diversification of the sources of rawmaterial regularly
used. This is not a new statement and it has been assumed a long time ago
by the whole industry in this activity despite of some remarkable problems.
Thus there is a clear research line, not yet fruitful, focused on identifying
renewable (vegetal) sources of n-3 long chain polyunsaturated fatty acids
(n-3 LC-PUFA) as a partial alternative to fish oils. Likewise there are many
efforts addressed to obtain protein concentrates of vegetal origin with the
same purpose.
Apart from identifying and introducing alternative ingredients the
evolution of feed formulation to obtain the best nutritional profiles requires
unavoidably new additives. Additional problems such as high densities and
the subsequent risk of disease transmission; limited and even forbidden
use of antibiotics; together with feed with a high vegetal content, lead to
a reduction in survival and growth as well as a lower efficiency in feed use.
All these disturbances make aquaculture activities not very profitable. In
order to promote growth and an adequate health condition there are several
useful tools to be used. Some of them are: the inclusion of natural growth
promoters in feed, the use of lactic bacteria to enrich cultures of Artemia and
rotifers in hatcheries, as well as the combination of mineral vitamin markers
with immune stimulant activity. Many of these substances have shown to
affect certain species causing benefits derived from their antimicrobial
effects, effects on the development of the intestinal epithelium, anti-
inflammatory or digestibility improver.
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