Page 18 - World Aquaculture Magazine - March 2011

16 March 2011
mals, genetically improved shrimp, value added goods, more
efficient feed and feed management that will lead to high
productivity and performance (Alves 2010). Although there
are specialty feeds available; such as those that contain pro-
biotics, prebiotics, immunostimulants and high protein lev-
els, shrimp are typically fed on 30-35 percent crude protein
and seven percent oil content.
Fish Farming
Fish farming started in the 1940s, with the first studies
being conducted by Rodoph von Ihering, known as the Fa-
ther of Brazilian Aquaculture, on the artificial reproduction
of native species to stock with juveniles of native species in
reservoirs. Aquaculture was not a business; it was consid-
ered an environmental activity until it was moved from the
Environmental Ministry to the Agricultural Ministry and,
actually in Brazil, there is now the Ministry of Fisheries and
Aquaculture, which is giving the sector the real importance
it has attained, thereby solidifying Brazil’s huge potential as
a world seafood supplier.
Although fish farming started about 70 years ago, the big
rise came in the 1980s with the use of pelleted feed, popu-
larization of the artificial reproduction of native species and
the introduction of modern strains of tilapia and carp, in
addition to hundreds of native species with good potential
for aquaculture in Brazil.
Until 1980, there were no formulated feeds for fish in the
Brazilian animal feed market. In the 1980s, pelleted fish feed
production began, especially for carp and trout that were in-
troduced to cold regions of the country. In 1992, production
of extruded feed started and yields went from 3,000 kg/ha/yr
to up to 40,000 kg/ha/yr, because of better formulations, use
of appropriate ingredients, feed management (floating feed)
and knowledge acquired by researchers.
Presently, fish farming has spread throughout the coun-
try. Tthough fish are poikilothermic and grow better in warm
regions, the largest Brazilian production is concentrated in
the south and southeastern regions, but it is growing faster
in the northeastern region.
In the northeastern region, tilapia (Oreochromis niloticus)
is the most popular farmed fish. Fingerlings are produced
in hatcheries, sex reverted to males with use of hormones,
stocked at 0.5 g, grown in small cages (4-18 m 3) and har-
vested at 800-1200 g at 5-6 months. In the hatcheries, brood-
stock are fed with 32-35 percent CP, 5-7 percent fat feed. Fry
are fed 45-55 percent CP feed and juveniles are fed 36-45
percent CP feed. During growout tilapia are fed 32 percent
CP feed if in cages, or 28 percent CP if in ponds. Feed con-
version ratio ranges from 1.5 to 2.0 for fishes grown in cages
from 0.5 g to harvest size of 0.8 kg to 1.2 kg, if in ponds
with abundant natural feed. Stocking densities ranging from
2 fish/m2 to 6 fish/m2; FCR ranges from 0.8 to 1.3:1 for fish
harvested at market size from 0.6 kg to 1.2 kg/fish.
Native species are also reared in the region and the most
important are the round fish, tambaqui (Colossoma ma-
cropomus), pirapitinga (Piaractus brachypomus) , pacu (P.
mesopotmicus and their hybrids), which are stocked at low
densities, ranging from 0.5-1.3 fish/m2 and are harvested at
1.2-2.0 kg average weight after 5-6 months (stocked at 30-40
g/juvenile) and FCR ranging from 1.2 to 1.5. Similar perfor-
mance is achieved in the northern region, where tilapia is not
allowed because of environmental regulations.
In the midwestern region, although there are no restric-
tions on exotic species, native species are the most popular for
farming. Carnivorous species are being reared in semi-inten-
sive and intensive systems with good performance. There are
specialized feeds and carnivorous Brazilian catfish (Pseudo-
platystoma fasciatum) reach 1.8-2.0 kg in 12-18 months; FCR
is about 2.0-2.5 and juveniles are available for most of the
year. Tilapia and round fishes are also farmed in the region.
The southeastern region has the greatest variety of species
being reared. Rainbow trout (Oncorhynchus mykiss), carp,
tilapia, carnivorous Brazilian catfish, round fish, bait fish,
ornamentals (native and exotic species), bull frogs (Rana
catesbeiana) and freshwater shrimp (Macrobrachium rosen-
bergii) are farmed in extensive to super- intensive systems.
This region has the largest cities in the country, the majority
of the population and the largest share of GDP. As in the
northeastern region, tilapia is becoming the most reared spe-
cies and performance is similar, except the length of the pro-
duction cycle is longer because of a winter season, although
not too severe, it is severe enough to diminish appetite as
well as growth rates. Fingerlings are produced in hatcher-
ies, sex reverted to males with use of hormones, stocked at
0.5 g and grown in small cages (4-18 m3) and harvested at
800-1,200 g at 5-6 months. There is at least one hatchery re-
verting tilapia fry into males without hormones, using high
temperature instead. In the hatcheries, broodstock are fed
32-35 percent CP, 5-7 percent fat feed, fry are fed 45-55 per-
cent CP feed and juveniles are fed 36- 45 percent CP feed.
During growth, tilapia are fed 32 percent CP feed in floating
cages. Low volume cages are typical, but farmers are shifting
to higher volume cages (up to 2,000 m3). Feed conversion
ratios range from 1.5 to 2.0 for fish from 0.5 g to harvest size
of 0.8 kg to 1.2 kg. Ponds, with abundant natural feed, are
used to produce juveniles of 25-30g to stock cages.
The southern region also produces a large variety of
aquatic animals: native omnivorous catfish, trout, round
fish, carp, tilapia and shrimp (L. vannamei), among others.
Farmers use fertilization in the early phases and formulated
feed during growth and finishing. Feed conversion ratios are
lower because of the use of fertilizers. Almost all species
reared in the country are also reared in the south, including
shrimp that are being more intensively farmed, with water
recirculation and biofloc systems.
Ingredients
Brazil has an adequate, year long supply of feed-grade
grains and agricultural byproducts that are used as raw ma-
terials for the animal feed industry. Most of them are good
ingredients for aquafeed allowing Brazil to aspire to a posi-
tion of prominence in the production of fish or production
of ingredients or aquafeed in the world, as well.
Most used ingredients are:
• Cereals and their byproduct meals and oils: including
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