People have been cultivating Tilapia for years: a bas-relief on a 4000-year-old Egyptian tomb shows tilapia held in ponds. Tilapia are low on the food chain and adaptable.

1. May | June 2014
EXPERT TOPIC - TILAPIA
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FISH FARMING TECHNOLOGY

2. 40 | INTERNATIONAL AQUAFEED | March-April 2014
EXPERT T●PIC
Welcome to Expert Topic. Each issue will take an in-depth look
at a particular species and how its feed is managed.
TILAPIA
EXPERT TOPIC

3. Tilapia a well
travelled fish
that finds
a market
everywhere
People have been cultivating
Tilapia for years: a bas-relief
on a 4000-year-old Egyptian
tomb shows tilapia held in
ponds. Tilapia are low on the
food chain and adaptable.
1
USA
Whitefish USA
Despite the overall decline in per capita fish
consumption in the US, popularity of tilapia
continues to grow.
According to the National Fisheries
Institute, consumption of whitefish in the USA
(cod, pollock, tilapia and pangasius) surpassed
that of shrimp and rose by 6.2 percent in
2012. Together with pangasius, tilapia is the
main driving force behind the growth in white-
fish consumption in the USA in recent years.
According to the USDA, the USA market
consumes close to 226,000 tonnes of tilapia a
year, more than four times the amount only
a decade ago.
Nearly all tilapia farmed in the USA are
raised in recirculating aquaculture systems
often employ “bio-filters” — microorganisms
that feed on nitrogen — to treat wastewater.
Bacteria break down some fish waste into
nitrogen (which the microorganisms absorb
for fuel) and other organic compounds that
can be used to grow plants and algae, which
are fed back to the fish. Sediment is removed
from the tanks mechanically, and 99 percent
of the water is recycled.
FAO Globefish reports that demand
for tilapia, including high value fresh fillets,
has grown strongly. Indeed, from January to
September 2013, imports of fresh/chilled (air-
flown) tilapia fillets into the USA increased sig-
nificantly by more than 40 percent in volume
and 44 percent in value compared with the
same period in 2012.
During the January–September 2013 peri-
od, imports from almost all major suppliers
were higher except from Ecuador, which
dropped its shipments to the USAby 17 per-
cent compared with the same time period in
2012. Fresh tilapia fillets from Honduras, now
the number one supplier of fresh product,
were up by almost 30 percent. Amounts from
Costa Rica and Colombia increased by 86
percent and 47 percent respectively.
During the first nine months of 2013, a
total of 137,300 tonnes of frozen tilapia were
imported, down eight percent from the same
period the previous USA year.
However, import values were up 17 percent
to US$693 million. The frozen fillet category,
which makes up the largest share of frozen tila-
pia product, experienced a 12 percent decline in
volume due to significant drop in supplies from
China, Indonesia and Honduras.
In addition, much of the production in
China is being diverted to African markets.
2
China
China unassailable
In China, the world’s largest producer of
Tilapia, had major issues in 2012 with damag-
ing weather, disease and low prices which
forced many farmers out of business.
However, production remained stable in
Fujian, Guangdong, Guangxi and Yunnan,
which are the major producing regions. Since
the latter part of 2013, demand for tilapia
fry from farmers has increased. Production
in 2014 is expected to be an improvement
over 2013.
According to FAO Globefish, total tilapia
exports from China during the first nine
months of 2013 were up seven percent in vol-
ume compared with the same time period the
previous year, reaching 268,000 tonnes. The
most popular category, frozen fillet, declined
in volume by four percent while significant
increases were noted in whole frozen (+19
percent) and breaded (+16 percent) catego-
ries. In terms of value, exports experienced
a 16 percent growth to US$925 900 million.
According to national sources, during the
first three quarters of 2013, exports of fro-
zen fillets to the US, China’s largest market,
declined by about 18 percent, while Mexico
imported 34 percent more.
Exports of frozen fillets to the EU mar-
kets increased, including Spain (+32 percent),
Poland (+62 percent) and Germany (+19
percent). Exports in this product category
to Costa Rica, Peru and Colombia also grew,
while exports to Iran and Southeast Asia
(Malaysia, Vietnam and Thailand) increased by
a total of 138 percent.
March-April 2014 | INTERNATIONAL AQUAFEED | 41
EXPERT T●PIC
3
4
2
5
6
7
1

4. For the first three quarters of 2013, the
whole frozen category experienced a 39
percent increase in value to US$196 million.
This category also took a larger share of the
total export volume at 36 percent compared
with 32 percent in the same time last year.
This growth was largely facilitated by higher
exports to African and Middle Eastern mar-
kets.
Alternative markets for China, such as in
Africa, are being explored due to the stringent
quality requirements the processing facilities
must meet for export to the USA and EU.
Supply constraints have also led processors to
either reduce processing or focus on whole
products to gain higher margin returns.
3
Taiwan
Taiwan on film
Taiwan PC produces an average of 70,000
tonnes of tilapia annually, 60 percent of which
is exported to the US, Canada, Saudi Arabia
and Republic of Korea.
In terms of frozen tilapia, Taiwan PC
exported 24,189 tonnes in the January–
September 2013 period, a 31 percent increase
compared with the first three quarters in
2012. The majority of the frozen category was
taken by whole tilapia at a 90 percent share.
Exports of whole frozen tilapia increased to
almost all markets except for Saudi Arabia,
Japan and Qatar.
In recent news, the Fisheries Agency
announced that Taiwan PC will be taking
active steps to promote tilapia raised in the
country. Marketing plans include producing
“films to introduce Taiwan’s high-quality tilapia
production industry” to promote Taiwanese
tilapia and help improve the image of the
industry.
Additionally, several of the Republic
of Korea’s importers were invited by the
Fisheries Agency and local industry groups
to visit tilapia farms in Taiwan and were
reported to have approved of the high quality
of the fish farms. The Republic of Korea is a
major importer of Taiwanese tilapia, mostly as
frozen fillets.
4
Vietnam
Vietnam’s potential
In recent years, Vietnam’s tilapia exports have
been recorded in small volumes.
During January to September 2013,
Vietnam exported about 1000 tonnes
of tilapia to the EU and US. The EU
absorbed the majority, at 80 percent.
In light of the challenges being faced
by the Pangasius industry, Vietnam is now
looking to tilapia production as another
potential for export. It was reported that
the An Giang province will be a hub to
develop tilapia farming for export, with
the Aquatic Breeding Production Center
training farmers to produce fingerlings in
the province and ensure sufficient seed
supply.
5
Brazil
Amazed by Brazil
Amazingly, Tilapia production in Brazil is grow-
ing at an average rate of 17 percent annu-
ally. According to The Ministry of Fisheries
and Aquaculture (MPA), tilapia production
exceeded 253,000 tonnes in 2011, showing
strong growth compared with 2010 (+63
percent), when production amounted to
155,000 tonnes.
The Ministry of Fisheries and Aquaculture
(MPA) plans to invest BRL 252,000 (US$107
860) in tilapia genetic improvements. The
project aims to train researchers and develop
new products for the Brazilian tilapia industry.
6
Trinidad
Trinidad surprise
Trinidad is the surprise packet as there has
been a significant increase in demand for
farm-raised tilapia. This demand has been
growing since 2013, after the Ministry of
Food Production embarked on a promotion
campaign and introduced initiatives to open
more markets for local farmers.
There are also plans to boost produc-
tion from farmers with not enough capac-
ity to meet the growing demand. The Sugar
Cane Feeds Centre (SFC) in Longdenville has
developed an arrangement to purchase tilapia
from farmers and process and market the fish
themselves. The SFC report that consumers
have been buying more farmed-raised fish
because of concerns regarding pollutants fol-
lowing the oil spills in December 2013.
7
Australia
Strange Australia
Strangely, in Australia Tilapia is considered a
noxious pest!
One of the main species found in
Australian waters is Oreochromis mossam-
bicus (Mozambique Tilapia) and that is a
species that normally lives in brackish water.
In many parts of Australia there are issues
in arid land areas with salty water. It makes it
very difficult to use the land/water for growing
crops and vegetables but is ideal for growing
fish and certainly growing tilapia but regretta-
bly it is not allowed as Australia would rather
invest in ‘silver bullets’.
“Tilapia is a popular food fish in Asia, Africa
and the South Pacific.
“However, the use of tilapia for con-
sumption in Queensland is illegal,” states
Europe
The European Union
connection
In the EU they imported 24 percent
more frozen tilapia fillets during the first
nine months of 2013 compared with the
same time period in 2012. This confirms
the positive trend from the first quarter
of the 2013 with close to 17,000 tonnes,
up 28 percent from the same period
in 2012.
Supplies from Indonesia, Vietnam and
Thailand continue to contribute margin-
ally to the EU’s imports while China
remains the dominant source, supplying
99 percent of the market. Spain, Poland,
Germany, The Netherlands and Belgium
are the largest importers of tilapia within
the EU.
Asia
Asia’s Lunar New Year
Asia has a strong affinity to Tilapia and
in response to the Lunar New Year
demand, prices of live tilapia have peaked
in retail markets as well as in restaurants
in Malaysia, Singapore and Taiwan PC. In
Malaysia, live tilapia comes almost entirely
from local sources, while Singapore gen-
erally imports its supplies. In Malaysia,
ex-farm prices of live tilapia have risen
from US$2.8 per kg in November 2013
to US$3.75 per kg in January 2014.
As part of the Lunar New Year
promotion, wholesale live fish retailers
in Kuala Lumpur are offering fish bundle
deals, which feature tilapia (sold as Red
Pearl) and jade perch sold together.
Prices for bundles in January 2014 ranged
from US$37 per kg to US$105 per
kg. Meanwhile, live tilapia are sold at
US$5.60 per kg and are expected to be
10–20 percent higher during the Lunar
New Year week. In seafood restaurants,
live tilapia is priced at US$15–19 per kg.
42 | INTERNATIONAL AQUAFEED | March-April 2014
EXPERT T●PIC

5. the Queensland Government in FAQ’s
on Deciphering Legal Jargon (http://www.
daff.qld.gov.au/documents/Fisheries_
PestsAndDisease/Stop-the-spread-Module-3.
pdf).
However in the very same document the
New South Wales Government states “Can
people eat tilapia? It is not illegal to consume
tilapia in New South Wales, as long as the
species isn’t being possessed alive. However,
you are strongly advised not to use the spe-
cies for consumption, as it is in the best inter-
ests of the environment to keep the species
out of circulation in Australia.” Confused now?
In another part of CSIRO they have
produced a document “Our Future World
— Global Megatrends” where they state
“whilst the state of biodiversity is in decline
and the pressure is rising so too is the human
response.”
(Are we to save what we cannot and
miss out what we need? Tilapia produces a
relatively cheap, white, skinless filleted fish that
does not taste like fish and demand for the
product worldwide is expanding so Australia
has made a strange decision – Publisher).
FAO last word
According to FAO Globefish demand for
tilapia, particularly for the live market, has
peaked in many Asian markets corresponding
to the Lunar New Year’s high consumption
period. In China, there is concern over ris-
ing competition from lower value species,
namely Pangasius in the frozen fillet segment.
In turn, exporters are targeting alternative
markets. However, overall tilapia production
is expected to increase in 2014.
March-April 2014 | INTERNATIONAL AQUAFEED | 43
EXPERT T●PIC
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participantes
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CHILE
Participe en
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LA EDITORIAL TÉCNICA Y DE NEGOCIOS LÍDER DE CHILE
and virulence variation [9, 29, 20, 45, 46, 37,
16, 38, 1]. This fact turns this disease into a
bacteriology minefield.
Treatment
The main method of treatment is use of
antibiotics. Oxytetracycline has often been
used around the world against RTFS [39, 4,
22, 28]. Amoxycillin and oxolinic acid have
widely been used In Europe [4, 6]. However
the development of antibiotic resistance
makes antibiotics an unsustainable method of
treatment [15].
A lot of effort has been put into develop-
ing a vaccine but little progress has been
made so far [15, 1]. Some experiments with
injectable vaccines, that have used either
formalin-killed or heat-inactivated bacteria,
have shown some promise but such vaccines
will be very impractical for farm scale fry
inoculations [15, 1]. Until a viable vaccine is
produced, the industry will have to rely on
the use of antibiotics for treatment, along with
good biosecurity and husbandry measures to
possibly avoid the outbreaks.
Barnes & Brown (2011) [1] suggested
that dietary research is warranted, such as an
evaluation of novel dietary ingredients in feeds
or improved feed formulations that lead to
changes in RTFS susceptibility.
Orego-Stim Aquatract L
Orego-Stim® is a natural feed additive
based on oregano, developed by Meriden
Animal Health. The oregano essential oil acts
as an immunity enhancer and growth promot-
er, with further benefits including antibacterial
and antimicrobial properties.
This section will be divided into two sub-
sections. The first outlines the mode of action
of oregano essential oil and the second dem-
onstrates its immunity-boosting properties
in aquaculture species. All the data in these
sections is obtained from studies conducted
by Meriden Animal Health.
Note: As the scope of this paper focuses
on the antimicrobial and antibacterial effects
of Orego-Stim®, growth promoting results
are not shown in the main text, however
results from commercial trials studying the
growth promoting effects of the product on
Rainbow trout, are shown in appendix 1 for
reference.
Mode of Action
Indirectly, Orego-Stim® acts as a growth
promoter and an appetizer. It improves feed
intake and digestion, boosts immunity and
has antioxidant and anticoccidial properties.
Primarily however, it is an antibacterial.
In general, gram-negative bacteria, in
contrast to gram-positive bacteria, have
both a cytoplasmic membrane and an outer
lipid cell membrane with a much smaller
peptidoglycan in between. As the ancestral
types of bacteria do not have the outer-
layer, it has been suggested that this extra
outer-layer in the gram-negative bacteria
has evolved as a protection against antibiot-
ics. This is a theory that could explain why
Table 2: Phagocytosis Activity of Catfish under normal conditions
Month Parameter Control
Enro
10ppm
OS
500ppm
OS
1000ppm
OS
2000ppm
Pool SE
Month 1
Phagocytosis (%) 42.55 54.55 23.72 56.85 70.31 5.59
Phagocytosis index (%) 20.31 44.62 33.57 45.61 87.12 14.02
Month 2
Phagocytosis (%) 9.54 10.57 14.23 14.22 17.00 4.84
Phagocytosis index (%) 1.36 1.45 4.06 4.19 4.18 2.21
Month3
Phagocytosis (%) 32.73 33.34 29.77 33.85 40.42 5.53
Phagocytosis index (%) 12.72 13.93 18.92 22.07 24.99 4.23
May-June 2014 | INTERNATIONAL AQUAFEED | 15
FEATURE
A/S

6. The nutritional &
immune impact of
Azomite in Tilapia
and Shrimp
by Damon Fodge and Doug Fodge, DF
Intl., LLC, Dirk Lorenz-Meyer, Behn Meyer
EU, GmbH and William T.H.C. Chang,
Lytone Enterprise, Inc.
A
zomite® is the trade name for
a naturally occurring mineral
product that has been used to
supplement livestock and aquatic
diets throughout the world for over a
decade.
During this time, a significant amount of
data has been accumulated from the use of
the product in farm trials, university tests and
private research organisations. At this point, it
is clear that azomite improves the quality of
animal feed and this leads to improvements in
performance, but a solid understanding of the
exact mode of action remains illusive.
The name is an acronym for ‘A to Z of
minerals including trace elements’.
It is mined from a deposit rich in trace min-
erals in the central part of the state of Utah
in the United States. Millions of years ago
this region was part of a freshwater lake and
the azomite site was formed when a volcano
spewed millions of tons of ash into that lake.
Today, the deposit exists as several large
hills and the site provides the source of the
natural inorganic mineral, which typically con-
tains approximately 70 trace elements. The
chemical composition reflects both the vol-
canic and freshwater sources (www.azomite.
com).
The material is listed in the US Code of
Federal Regulations (21 CFR 582.2729) as
an anticaking agent for livestock feed and is
generally recognised as safe (GRAS) by the
US Food and Drug Administration (FDA).
Agriculture and livestock producers have
used azomite to improve feed quality and as
everyone knows improving feed quality leads
to better livestock health and plant nutrition.
Azomite falls well within the guidelines for use
in animal feed by the Association of American
Feed Control Officials (AAFCO).
Hundreds of years ago it was used by
the local native people in agriculture. This
eventually led European settlers to explore
the natives’ use of it for their animals and
gardens. In modern times, an entrepreneur
named Rollin Anderson mined the product in
the 1940s and gave samples to friends, some
of whom were skilled at testing agricultural
products. Mr Anderson’s activity paved the
way for azomite’s use in sizeable international
animal and agriculture markets.
Poultry, shrimp and tilapia farmers have
used it in their feed in conjunction with their
regular trace mineral mix for many years
and claim that it boosts the quality of their
feed and leads to improvements in weight
gain, feed conversion and livability. Examples
of the impact that the product has on live
performance in tilapia and shrimp (Burapa
and Shanghai Ocean Universities, respectively)
are shown here. This research has shown
improvement in weight gain and feed conver-
sion of up to 10 percent in multiple scientific
tests.
Improved availability
Trace minerals are essential in animal
diets because they participate in biochemical
processes required for normal growth and
development.
However, examination of azomite and its
typical amount of 70 elements reveals that
there are not enough of the essential trace
and ‘ultra trace’ elements to be the sole min-
eral source for the proper nutritional develop-
ment of animals and plants (Hooge, 2008).
Moreover, perhaps no more than one
percent of this inorganic product is soluble
in water (Ba, B, Ce, Co, Cr, Ln, & Zn are
sparingly soluble, Larsen 1990s), and X-ray
diffraction analysis reveals that the product
exhibits <18 percent physical structure (due
to a small amount of granite and pseudo
granite in the product) and the remainder of
the product is amorphous, without discernible
physical structure.
Perhaps this lack of physical structure
improves the availability, but that has not yet
been tested.
Although the product is an HSCAS
(Hydrated Sodium Calcium Alumina Silicate)
the lack of physical structure makes it an
atypical HSCAS.
When the materials was introduced to the
meat industry, researchers already knew that
natural inorganic minerals in use at that time
were poorly absorbed and did not fully satisfy
an animal’s nutritional needs.
Efforts to increase the absorption and
metabolism of six or seven of the well-known
trace minerals are still underway, but efforts
have already provided metal chelates that
exhibit much improved bioavailability due
to unique chemical characteristics (AAFCO,
1997). The use of natural inorganic minerals
in animal diets has decreased because they
typically provide <25 p[ercent of the minerals
needed by animals.
Significant improvement
Azomite does not appear to fit the gener-
alisations about inorganic minerals.
Two decades of animal scientific testing of
the product for weight gain, feed conversion
and livability improvements revealed that >85
percent of the tests yielded significant (p <
0.05) improvements.
In these tests, all feeds contained the
regular commercial trace minerals to which
azomite was added. These successes raise a
question: with a trace mineral content that is
low and practically insoluble in water, what
Table 1:
AZOMITE® % 1st Deaths (O2) 50% Death (O2) 100% Death (O2)
0 % 4th Hr (1.2 mg/L) 11th Hr (0.05 mg/L) 14th Hr (0.03 mg/L)
0.8% “ “ “ “ “ “
0.2% 5th Hr. (0.6 mg/L) 14th Hr. (0.03 mg/L) 16th Hr. (0.025mg/L)
0.6% “ “ “ “ “ “
0.4% >5th Hr. (<0.6 mg/L) 14th Hr. (<0.03 mg/L) 17th Hr. (0.02 g/L)
44 | INTERNATIONAL AQUAFEED | March-April 2014
EXPERT T●PIC

7. could explain these benefits? That question
leads to a multitude of hypothetical explana-
tions, but we tested two simple hypotheses:
1) that azomite inclusion in feed leads to
improvements in animals because digestive
enzymes are boosted and;
2) improved livability is due to increases in
innate immune enzymes (Liu et al. 2009) and
(Fodge et al. 2011).
A few other supportive tests were also
conducted.
Studies in feed
Researchers added test amount of azomite
to standard tilapia and shrimp rations.
An equal amount of flour was replaced in
the experimental diets by the azomite, and
the diets were not isocaloric. Three or four
replications per test group were used in the
tests. Dissolved oxygen, pH, temperature, etc.
were maintained as close to normal as pos-
sible. Enzyme activities were measured using
standard test materials available commercially.
In addition to the measurements of enzyme
activities, investigators also measured weight
gain, livability and feed conversion (FCR) and
although not shown, weight gain boosts were
@15%, FCR improvements @10% and livabil-
ity was better in the presence of the material.
As is clear from the study on digestive
enzymes shown below, 0.2% to 0.5% azomite
boosted the activity of 4/5 of the proteo-
lytic enzyme activities that
were measured and also
increased lipase activity in
the shrimp. Some enzyme
activities were increased as
much as 30-40%, and this
result helps explain why
one obtains weight and
FCR improvements.
Although not shown,
dry matter and crude
protein digestibility were
assayed in the tilapia and
both were improved (p
<0.05) 9.9% and 1.75%,
respectively.
Enzymes of tilapia and shrimp innate
immune systems were examined next, and
the table below shows the results.
azomite in the feed boosted tissue con-
centrations of lysozyme (+ @40%), super-
oxide dismutase (+ @15%), phenoloxidase
(+ >90%) and alkaline phosphatase (+25%).
The increases in both digestive and immune
enzymes may be a hint that the explanation
for the mechanism is quite complex.
To illustrate the potential complexity,
azomite’s contribution of individual trace min-
erals to feed would contribute @0.1 to 1.0mg/
kg to the feed of aquatic animals that require
several trace minerals at the level of many mg/
kg of each.
To add to the potential complexity of
the mechanism, anecdotal reports indicate
that less diseased pepper, tomato and grapes
occur in the presence of azomite than in it’s
absence. It is known that plants depend on an
innate immune system that somewhat resem-
bles that of invertebrates (Jones and Dang,
2006). Could it be that something more than
simple availability or ratio of trace mineral X
to Y would be required to explain azomite’s
mechanism?
Although the mechanism for induction of
such large amounts of enzymes may elude us
at this time, shrimp and fish are subjected to
more challenges by pathogens and oppor-
tunistic pathogens than other commercial
March-April 2014 | INTERNATIONAL AQUAFEED | 45
EXPERT T●PIC
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8. animals, and it is interesting that feeding
animals a small amount of asomite appears to
more adequately equip them to meet such
challenges.
To establish that an increase in immune
enzymes was not an artifact, the researchers
challenged shrimp with Vibrio alginolyticus
and measured the accumulated mortality four
days after infection.
Only 13.5% of the shrimp that did not
receive any AZOMITE® in their diets were
alive after four days, but @ 43.5% of those
with @ 0.4% azomite in their feed were still
alive.
The aquaculture research and develop-
ment teams did not measure antibody synthe-
sis +/- azomite, but poultry researchers have,
as the test result below indicates.
There were four test groups with eight
baby chicks per test group.
Feed for each group received 0.5% of sand
or calcium bentonite or sodium bentonite
or azomite, all of which were similar particle
size. At 16 days, each chick was injected with
sheep red blood cells (SRBC) and six days
later blood samples were taken from each
bird to measure total antibody and IgG activi-
ties/ml specific toward SRBC.
As is clear, the antibody level in blood from
the birds eating azomite contained @66%
more antibody activity than any of the other
groups (p < 0.05).
Next, the aquaculture researchers wanted
to determine if azomite-treated feed would
help shrimp survive hypoxia. They subjected
shrimp that had consumed azomite in the
feed to gradual oxygen deprivation (see
below).
The group with 0.4% azomite in the
feed withstood hypoxia the best, but in our
opinion more rigorous testing is needed to
confirm this result.
Nonetheless, lack of dissolved oxygen
for shrimp and fish has a profound impact
due to the extreme growth densities of
commercial animals. Invertebrates depend
on hemocytes to phagocytize pathogens
identified by innate immune receptors.
Movement of hemocytes to sites of inva-
sion and the total number of hemocytes
produced under low oxygen tensions would
be stressed if animals depend on anaerobic
energy metabolism (Direkbusarakom and
Danayadol, 1998 and Le Moullac et al.,
1998).
Studies when added to shrimp pond soils
Shrimp farms have tested azomite by
fertilizing the soil of the ponds between
grow-out periods. Pond soils are treated with
@200kg/ha. Live performance, mortality, pH,
phytoplankton and zooplankton and dissolved
oxygen levels are measured.
In one thorough field study (six matched
ponds – three were control and three were
test ponds), an average of 17% increased
weight and 30% less mortality were observed
in the azomite ponds.
Moreover, both zooplankton and phy-
toplankton levels were boosted 800-900%.
pH values taken in the morning and at noon
were numerically slightly higher in the test
group than the control, but dissolved oxygen
in the test group was increased @30% in the
morning and was still 8% better at noon than
the control values.
Currently, asomite is added to the pond
soil between grow-outs at shrimp farms,
especially extensive farms, in several countries.
For years it has been known that it is
necessary to have the correct forms of trace
minerals available for animals and to provide
those trace minerals in the correct propor-
tions - an observation that is perhaps as
important as the presence of a 100% available
metal-chelated mineral.
Little research is underway that explores
the ratios of ultra trace minerals to each other
as ‘university personnel’ who might be able to
provide answers are faced with limited avail-
able funding for such exploratory research.
Our conclusion is that the proportions of
trace minerals should receive higher priority in
future research.
Conclusion
Azomite appears to enhance tissue protein
synthesis (perhaps even beyond simply diges-
tive and innate immune enzymes) leading to
improvements in weight gain, feed conversion
ratio and lean yield in aquatic species.
Moreover, the product improves the sur-
vival rate, apparently due to its ability to boost
the immune enzyme response and perhaps
also increase mucosal and shell strength.
It is clear to us that azomite provides some
trace minerals that are important in animal
nutrition. It will be satisfying to determine the
exact nature of those minerals that are not
currently being added in most animal diets.
References
Hooge, D.“Natural Minerals Can Benefit Broiler
Diets”, Feedstuffs 80(3): 24-26, 2008.
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Direkbysarakom, S. and Y. Danayadol. “Effect
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Le Moullac, G., C. Soyez, D. Saulnier, D.
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Fodge, D., S. Rattanagulvaron, N.T.M. Huong.
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Rodriguez, A., I. Lopez, E. Sujka, S. De la Cuesta,
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Cook, M., N. DiNicola,W.Wu, E. Smalley,“Effects of
clay products on Fusarium mycotoxins in broiler
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Larsen, C.“Trace elements in AZOMITE® that was
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system”. Nature, 444(16): 323-329, 2006.
46 | INTERNATIONAL AQUAFEED | March-April 2014
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