EXPERT TOPIC - TROUT

May | June 2012
Feature title: EXPERT TOPIC - TROUT

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or by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1464-0058

The International magazine for the aquaculture feed industry

EXPERT T●PIC

TROUT
EXPERT TOPIC

Welcome to Expert Topic, a new feature for International Aquafeed. Each issue will take an
in-depth look at a particular species and how its feed is managed. To kick off the first Expert
Topic, trout takes centre stage. Over the next pages you'll find, amongst other things, a
feature on the trout value chain in Peru, a glimpse behind the scenes at Bibury Trout Farm in
the UK and an overview trout culture and feed in Turkey. First of all, industry experts from
around the world give the inside track feed and management in their country. Enjoy.

22 | InternatIonal AquAFeed | May-June 2012

EXPERT T●PIC

 4 3

+



+



Perspectives on trout farming and aspects relating to fish feed

Peru
 According to an article published by FIS.com, the company
uses the same technologies applied in fish farming by the major
by Anna Pyc, Peruvian Aquaculture Company, Peru producers of salmon and trout, like Norway, Chile and the United

T
Kingdom.
he highest industrial aquaculture center in the world is However, this technology has been adapted to its unique environ-
located in Peru's central Huancavelica department, 4,600 ment and an individual model has been developed for the high Andes.
meters above sea level. Peruvian Aquaculture Company The natural environment and the purity of the water in this mountain
(PACSAC) was founded in 2007 for the development of range is the greatest asset of the company, which allows making aqua-
industrial aquaculture, an activity that is emerging worldwide as the culture a sustainable activity.
main protein source for the near future. All procedures used by the company are environmentally friendly,
and as a result, the Peruvian Aquaculture Company implements norms
To meet this goal, PACSAC integrates social and environment care ISO 14001: 2004. PACSAC also develops regular environmental water
with the use of modern technologies that make possible to provide quality monitoring to asses quality and sediment.The fish are fed exclusively
products to international markets. At this stage, PACSAC is raising rainbow with extruded fishmeal specially formulated for trout. After reaching
trout. As well as beign the higest trout farm in Peru, the company's facilities the required market size the trout are harvested and transported to
are also the largest industrial aquaculture site in the country. the processing plant.

totally in Turkey. Foreign feed mills have built fish feed plants in

Turkey
 Turkey because of increasing demand by farms. Trout farms choose
feed mills according to their prices and payment ease.
Rainbow trout have differences between them because of geographic
by Prof Dr Belgin Hossu, Faculty of
Fisheries, Ege University, Turkey conditions of the country. Depending on these changing conditions,

A
FCR is between 0.84- 0.97. The main protein source of feed is fishmeal.
ccording to the latest parametres from the Turkish Fishmeal sources are foreign countries and sardine and anchovy from
Statistics Office, rainbow trout production is around Black Sea according to the fishing seasons. Protein rate of feed is around
85.244 tonnes in Turkey and is increasing each day. 44 percent at growing ages. In addition to fishmeal, vegetable protein
Farms are mostly on land and damed lakes with a small sources have been used to decrease the cost of the feed. These are soy-
amount in sea cages. bean meal, corn meal and wheat meals. Adding of caroteneids generally
happens at salmon breeding or matured fish of trout.
Rainbow trout production in Turkey can be divided in to two The feed manufacturing system is extruder. To decrease waste,
parts. The reason for this is the continously changing cost of feed floating feed is prefered.
due to fishmeal and fish oil prices. Unstable prices of fishmeal and Generally, the colour of the meat isn’t important because trout
fish oil has forced the farms to produce their feed themselves. As is consumed both fresh and frozen. On the other hand, yellow col-
a result, the feed sector has to be seen as commercial feed mills oured meat isn't preferable because it indictaes high levels of corn
and self-feed producers. Feed production for rainbow trout is done and soybean meal.

May-June 2012 | InternatIonal AquAFeed | 23

EXPERT T●PIC

Poland
3 the approximate FCR reaches values of starter feeds at 0.72 and, in
fingerlings production 0.88. In recent years there has also been invest-
ment in automatic feeding systems to improve feeding effectiveness.
by Anna Py, Aller Aqua, Poland

T
Very strict regulations in Polish law regarding the environmental impact
rout farming in Poland is situated mainly in the northern of salmonids production also require that feeds that meet certain standards.
part of the country with its main species – rainbow trout. According to individual farm water conditions the feed is chosen in respect
It is relatively young part of the Polish aquaculture reaching of its caloric value and other properties. Many of the farms have their own
14 thousand tons of annual production in 2010 with a hatcheries, where starter feeds are used. These feeds are especially important
value of approximately €40m. The farms are modern, many using for having high survival rate and fish in good condition as a basis for fast growth.
partially recirculated systems and technology reducing environmental Fish feed is the largest cost component of trout farms, amounting
impact. Over 200 trout farms employ approximately 1000 people. on average to about 34 percent, however it used to reach over 40
The location of farms in rural areas makes them important for local percent in previous years. Cost of labour, live raw material and other
employment levels. operational costs amount to 19 percent , 16 percent and 14 percent
respectively. Other components costs are relatively small.
Trout farms in Poland use high quality feeds purchased from leading Polish trout production faces new challenges in terms of market
feed producers in Europe. 41.5 percent of the market share belongs demands as well as increasing pressure on reducing environmental
to Aller Aqua (2010), in the second place is Biomar (34.6 percent) impact. The Polish Trout Breeders Association faces these challenges
and third is Skretting (12.3 percent). Aller Aqua is the only fish feed and among other activities introduced a four year promotional cam-
company with a production plant in Poland, which makes the company paign of trout in Poland. The campaign focuses mainly on promoting
competitive regarding delivery conditions. trout as a source of healthy nutrition, as well as spreading knowledge
Trout farms in Poland are in most cases well managed and therefore about the species.

Denmark
4

by Brian Thomsen, Director
Photo courtesy of ©Dave Bassett, Chief

Danish Aquaculture Organisation

D
Executive, British Trout Association

anish trout farmers almost exclusively use
fish feed manufactured in Denmark. The
mains reasons are that they view it as
being superior and that it is in compliance
with national legislation. Danish national legislation also
regulates digestibility but most types of feed exceeds the
legal requirements.

Key decision parameters when choosing a feed include:
low FQR, high growth rates, national regulation, environ-
mental impact – in general 'price/performance'.
The national average FQR is approximately 0.94, thus
we use on average approximately 940g of feed to make
1kg of trout. The protein content is gradually declining but
it is typically around 42 percent. The main protein source
is fishmeal.
The legislation for freshwater farming was changed this
February. One of the key changes is that farms may now
choose to be regulated on output (discharge quotas) and
not on input (feed quotas). This will probably puts even
more emphasis on the 'price/performance' ratio.
The fish farmers are well aware of the fact 'that we are
what we eat'. Therefore quality is of the highest importance.
We mainly farm white fish but caratenoids are used in fish
feeds that are used to make pink trout.
The cost of feed is always a key factor but the cost is
judged against performance. The key question is therefore
not the price per kg per se but the 'price/performance'
ratio.
We produce approximately 10,000 tons of trout in
marine farming and 25,000 tons in freshwater farming. The
gross output (2010) was approximately φ45m for marine
farming and φ80m for freshwater farming. The industry
employs approximately 1000 people (including production
and feed and processing).


EXPERT T●PIC

United Kingdom


by David Bassett, British Trout Association

U
K trout farming differs
to some other countries
in that the UK employs
a number of different
production methods. Trout are farmed
in freshwater open net pens, earth
ponds and concrete raceways and are
also farmed in open net pens in marine
water off the west coast of Scotland. UK
trout farmers also employ recirculation
technology – most commonly as partial

recirculation in hatchery facilities rather
David Bassett

than the entirely closed recirculation
sites as may be seen elsewhere.

The UK primarily produces rainbow trout, although brown trout
are farmed too. Both species may be farmed to organic standards, and
consequently use organic feeds, although this market remains small,
producing only in the hundreds of tonnes. Both brown and rainbow
trout are farmed for the restocking market (i.e. sale of live fish for
stocking to fisheries) although the majority of fish that are farmed are
for the table market.
Production tonnages vary annually, but current official statistics
suggest that circa 11,000 tonnes of table trout are farmed each year,
with a further circa 3,500 tonnes for restocking. Large trout production, as wide a basket of ingredients as possible, to optimise variations in the
those fish farmed in marine water, is increasing, with 2011 production commodity market.
being estimated at 2,000 tonnes, up from circa 1,600 tonnes in 2010. With the exception of fish farmed to organic standards, the UK
Fish feed accounts for approximately 50 percent of production market prefers fish that is “pink” fleshed. As such, astaxanthin on can-
costs, and so is of paramount importance to UK producers. Through thaxanthin are included in the formulation of diets.
both European Union and UK domestic legislation, fish feeds, their Most UK feeds for the table market avoid using land animal protein.
composition and their use, are tightly regulated. The vast majority of Although permitted to do so by law, retail buyers seem reluctant to
trout farms source feed from the major commercial suppliers. Skretting purchase fish fed using such diets. However, research undertaken
has the largest market share, although other suppliers include EWOS, by industry and other third parties suggests that there is little to no
Biomar, Le Gouessant and Aller Aqua. However, whilst costs are high, opposition to the inclusion of such protein sources on the part of the
trout farmers seek value for money and a return in terms of perform- consumer / general public, who remain generally unconcerned about
ance and as such would prefer to pay for a top quality feed in that this the diets fed to farmed fish.
is a better investment in the long term resulting in a better yield and In common with other sectors, 'sustainability' is a term that is used
healthier fish. increasingly often with regard to fish farming and fish feeds. Whilst a
Feed compositions vary between manufactures and specific formu- definition of sustainability is always hard to achieve, it would be fair to
lations / diets. The major source of protein continues to be fish meal. suggest that much greater emphasis is now being placed upon such
Increasingly, producers seek to be able to vary the inclusion rates in issues as Fish In Fish Out (FIFO). As a trade association representing the
diets of such ingredients as fish and vegetable oils. With the global UK farming industry, the British Trout Association is increasingly liaising
commodity index affecting the price of key ingredients, trout farm- with feed companies and NGO organisations over issues relating to the
ers support feed manufactures in their attempts to operate using inclusion percentages of fish meal and fish oil in diets, and the origin
of the fish meal and fish oil that is used. It is predicted that greater
emphasis will be placed upon such issues in the future, with certain
certification schemes placing greater emphasis on the sustainability
imprint of all aspects of production. How much importance consumers
attach to this has yet to be demonstrated.

UK fish farming is strictly regulated in relation to discharges into
the aquatic environment. As such, farmers pay close attention to feed

conversions ratios and associated nutrient discharge and suspended
solids. Whilst feed conversion ratios vary across the UK, given the wide
range in production systems, water temperatures and other variables,
feed conversion and feeding protocols have continued to improve in
sophistication and understanding with reported ratios varying from
under 1:1 (typically 0.95) to 1.2 :1.
UK trout farmers enjoy a close and mutually beneficial working rela-
tionship with commercial fish feed manufacturers and as an industry we
continue to work together to be at the forefront of trout production.


EXPERT T●PIC

Farm Focus

Buxton
Trout and
Salmon Farm,
Australia
by Mitch MacRae, Secretary of
the Australian Trout & Salmon
Farmers Association

A
t Buxton Trout & Salmon Farm
we have a general feed conver-
sion rate of 1.1 – 1.2. Protein
content of the feed we use is 45
per cent and the percentage of fish meal is
not known. There are only 2 feed suppliers
in Australia, we chose Skretting as their
feed performs better (better FCR) without
compromising environmental targets on
discharge and is more economical because
of freight costs.

The taste of the trout is not affected by
the feed, however the colour is depending
on how much colour is added to the feed.
Costs of feed and FCR are important factors
as margins are tight, and fish feed is one of
our biggest costs. On average to produce
"The taste of the trout is not 1kg of trout we will need 1.1 – 1.2kg of feed.
affected by the feed, however the In Australia approximately 1500-2000
tonnes of trout are produced each year,
colour is depending on how much with approximately 85 per cent of Australia’s
trout being grown in the Murrindindi region
colour is added to the feed" in Victoria. Australia’s trout production has an
approximate value of 10-15 million dollars per
year and employs approximately 200 people.
Above & Below Mitch MacRae on the grounds of Buxton Trout Farm
Photos courtesy of ©Mitch MacRae

Farm Focus


6
EXPERT T●PIC

white trout. In the Black Sea, fish are the market competition is getting more stress-
reared in cages up to 0.5–1.5 kg and ful for producers. As a consequence of
sold as 'Black Sea salmon'. competition between farmers, feed producers
Steadily increasing production are always introduced the best available feeds
has accompanied a large volume in order to reach desired size as quickly as
of fish feed needs. Trout feeds are possible. So the growth rate is almost primary
produced in state-of-the-art facilities factor feed driven. The intrabrand competi-
using leading-edge quality assurance tion occurs also among feed producers.
techniques. There are currently 10 feed The environmental pressures and impacts
mills with the total capacity of over 300,000 caused by the typical production of rainbow
tonnes per year. Almost all feed mills produce trout in Turkey have been taken into consid-
trout, sea bass and sea bream feeds using eration particularly in the last decade. After
extruding technology made after 2000. Since the adoption of new regulations on aquac-
the regulatory standards are high, all fish mills ulture in Environment Law, all aquaculture

Trout culture
track raw materials acquisition, handling and facilities are under a monitoring programme.
storage, production processes and packaging Through implementation of a control pro-
and delivery. gramme the farmers are directly or indirectly

and feed in
The main protein source is always declared forced to use better quality feeds particularly
as fish meal. But reliable data on this is hard in low phosporus content. Since the overall
to obtain. Although Turkey has different production is increasing steadily, this pressure

Turkey
zones all around country having various water is expected to increase in near future.
characteristic features, the feeds are produced
regardless ecological differences as imple-
mented in some countries by chosen different
by Dr Atilla Ozdemir, Central Fisheries
Research Institute, Turkey
Table 1: High quality feeds from hatching to

A
harvest are produced in different size range
lthough Aquaculture has a relatively Starter feeds 300-1500micron
short history in Turkey, it began with
rainbow trout (Onchorhynchus
Pregrowers 2 – 3mm
mykiss) and common carp (Cyprinus
carpio) in the late 1960s and developed further Grower feeds 4 – 10mm
with gilthead seabream (Sparus aurata) and Broodstock 10 – 12mm
European seabass (Dicentrarchus labrax)
culture in the mid-1980s. Production reached protein/lipid/energy ratios.
167,000 tonnes a year in 2010 of rainbow trout, There is high variation in FCR depending
seabass, seabream, mussel, common carp and on feed management in farms and location

other species, produced on nearly 2100 farms. of farms. The lowest rate obtained in cages

in Black sea as 0,9 and highest as 1,2 in inland
The rainbow trout has been cultured farms. The effect of type of feed on taste and
since the early 1970s and Turkey has become colour of the fish is has not been considered
one of the top trout producing countries in very much so far.
Europe with an annual production of over The initial on-farm experience and follow-
85,000 tonnes, or almost 50 percent of the ing demands/complaints from processing units
country's total aquaculture production. With may lead producers to select the best avail-
the surprising appropriate ecological supply able feed. No carotenoids are incorporated
for trout culture in the marine environment into most trout diets produced in Turkey
thanks to low salinity the Black Sea has an but in some cases producers in Black Sea
enormous potential. Today there are more demanded pigmented feeds.
than 20 sea-based farms which are situated The cost and quality are almost equal fac-
in the Black Sea. This tends to increase in tors in choosing feed. As production increases,
number of fish farms and production.
Apart from marine and some freshwater Table 2: The protein/lipid content of feeds
cage farms in lakes and reservoirs, the major- may vary among producers but can be
ity of the trout farms employ small concrete summarized in following table
raceways mainly using stream waters. In the Crude protein Crude lipid
Size
past ten years, trout cage culture in dams has (%) (%)
reached a very important level of production.
Over 50 percent of the farms have their 300-1500
50-56 12-18
own hatcheries with eggs being produced micron
during the natural breeding season (between 2 – 3 mm 45-50 18-20
December and February). Ongrowing in race- 4 – 10 mm 43-45 18-23
ways lasts between 12 and 24 months. The
10 – 12 mm 47-50 14-20
majority of fish are sold locally as portion size


EXPERT T●PIC

Farm Focus

Behind
the scenes
at Bibury
Trout Farm
A working trout farm
that is attracting new
business from tourism

by Kate Marriott, General Manager,
Bibury Trout Farm, United Kingdom

B
ibury Trout Farm is one of Britain’s oldest, and country, approxi-
certainly most attractive, trout farms. Founded in 1902 mately 80 tons. A
by the famous naturalist Arthur Severn, the farm was small proportion (20
set up to stock the local rivers and streams with the tons) are sold to
native brown trout. Today, it covers 15 acres in one of the most other trout farms to
beautiful valleys in the Cotswolds, the Coln Valley. The Farm has supply the table mar-
diversified over the years, and the leisure side of the business now ket and are sold to
plays a very important part. local hotels, wholesal-
ers and to the public
Situated in through both the
the heart of farm shop and farm-
the beautiful vil- ers markets as fresh
lage of Bibury, gutted trout, fillets
the farm ben- or smoked trout, all
efits from the smoked and pack-
large number aged on the premises.
"The Farm has diversified of tourists who On the farm visi-
over the years, and visit the region. tors can learn about
The crystal clear the rainbow and
the leisure side of the waters of the brown trout while
Bibury Spring they wander in the
business now plays a provide the beautiful surround-
very important part" essential pure ings. There is a chance to see grading in progress when the fish
water required are selected for size and quality before being transported to new
to run the homes in oxygenated water in specially made fibre glass tanks.
hatchery which Information boards give a insight to what goes on in the hatch-
spawns up to ery and fryary areas and staff are on hand to answer any questions.
six million trout Feeding is done daily by staff and the water comes to life as the
ova every year. fish vie for the last morsel.
Up to a For the more adventurous, or the budding fisherman, Bibury's
third of the ova Catch Your Own Fishery is an ideal opportunity to catch your
are sold to out- supper or get hooked on a new hobby. Open at weekends during
lets throughout March - October, and during the local school holidays, we provide
Britain and all the equipment and help if required.
occasionally In addition to the farm, our recently refurbished fish shop
Farm Focus

abroad. The which now houses a wonderful range of wines, deli products, and
remainder are preserves as well as quality breads, eggs, and milk.
grown on and The Trout Farm is situated in the centre of the village of Bibury,
sold to supply next to Arlington Mill. Bibury is between Cirencester and Burford
angling waters in the United Kingdom
throughout the Website: www.biburytroutfarm.co.uk


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7
EXPERT T●PIC

(IBD) of chickens and X virus of Drosophila tally inoculated and re-isolated from zebra
melanogaster. This birnavirus is single-shelled fish eggs (Brachydanio rerio).Some IPNV
icosahedrons with characteristic isometric hex- cases have been reported in American and
agonal profi les and has a diameter of about European eels (Anguilla anguilla). However,
60nm. The genome consists of two segment the infection in Japanese eel (Anguilla japonica)
of double-stranded RNA. Genome segment A has a greater economic impact.
encoding two structural proteins (VP2 y VP3) In summary, the IPNV has been identified
and a nonstructural protease, while segment B in a number of teleosts family fish: Anguillidae,
encoding for a RNA polymerase. VP2 protein Atherinidae, Carangidae, Channidae,
induces the production of specific-type neu- Cichlidae, Clupeidae, Cobitidae, Cyprinidae,
tralizing monoclonal antibodies. It is thought Gadidae, Esocidae, Percichthyidae, Percidae,
that VP2 contains all the epitopes recognized Pleuronectidae, Poeciliidae, Salmonidae, and
by these antibodies. Sciaenidae.
The serological classification scheme of
Hill and Way recognizes nine different IPNV Transmission, carriers and vectors
serovars into the serogroup A. Seven of Infected fish can transmit the virus by both

Emerging these serotypes have been identified in IPNV
rainbow trout isolates. Serogroup B includes
horizontal and vertical transmis-
sion. These fish shed the

disease in a single serotype represented by the TV-1
archetype isolated from brown trout (Salmo
virus by urine and
faeces, con-

Mexican trout
trutta) and common carp (Cyprinus carpio). trib-
Each serotype includes a number of strains
that differ in virulence. This variation
complicates the disease which is
by Celene Salgado Miranda, Mexico State little understood.
University, Mexico

I
nfectious pancreatic necrosis (IPN) is a
disease caused by a birnavirus affecting
several wild and commercial aquatic
organisms. Salmonid species are the
most affected, having an important
impact in the salmon and trout
culture due to a high rate mortality
of fry and fingerling. IPN disease
is listed in the fish diseases of
the International Health Code,
World Organization for Animal
Health (OIE). For this reason, any
IPN outbreak has to be reported. uting to
The epizootiological knowledge the horizontal trans-
of the IPN is relevant for estab- mission. In breeding fish, it
lishing preventive and control has been demonstrated that the IPNV is
strategies against both disease and vertically transmitted by viral adsorption to
causative agent. the surface of spermatozoids, or it can be
Epizootiology present in the follicular fluid, but not in the
Natural and experimental hosts Salmonids nonfertilized eggs.
Distribution are the most susceptible species under natu- Bebak et al. experimentally determined the
The IPN and the causative agent (IPNV) ral conditions. The brook trout (Salvelinus IPNV excretion patterns in rainbow trout fry.
has been reported in several countries: fontinalis) is the most susceptible one to The time between challenge and excreting,
Australia, Canada, Chile, Denmark, Scotland, lethal effects of IPNV, followed by rainbow and challenge and signs onset were evaluated.
Spain, Finland, France, England, Italy, Japan, trout (Oncorhynchus mykiss) and Atlantic The authors also estimated the rate of
Norway and Switzerland, among others. Based salmon (Salmo salar). Also, IPNV has been iso- susceptible-excreting fish into a population
on these reports, IPN is regarded as a world- lated from artic char (Salvelinus alpinus),brown from inoculated IPNV fry. It was demonstrated
wide distributed disease. In Mexico, IPNV was trout (Salmo trutta) and lake trout (Salvelinus that IPNV-infected rainbow trout fry shed the
identified in 2001 from US-imported rainbow namaycush). virus two days post-inoculation, and the shed-
trout fry. In a recent study, the IPNV was iso- The IPNV has been isolated from impor- ding is increased, and approximately decreased
lated from three rainbow trout breeding farms tant non-salmonid species in marine aqua- after 12 days post-inoculation. More than 75
located at Mexico State, Mexico, regarded as culture: turbot (Scophthalmus maximus), percent of the rainbow trout population was
the main producer of this fish species. sole (Solea senegalensis) and Atlantic hali- infected in less than a week from the beginning
but (Hippoglossus hippoglossus).Also has of the viral shedding.
Etiology been isolated from some fishs as pike (Esox In rotifers (Brachionus plicatilis) it has been
The causative agent of IPN is a virus belong- lucius), goldfish (Carasius auratus), discus fish observed birnavirus lesions associated with
ing to the Birnaviridae family. Other members (Symphysodon discus) and bream (Abramis an IPNV-like virus. It is likely that invertebrate
of this family include infectious bursal disease brama), among others. IPNV was experimen- animals used as living-food for seabream and


EXPERT T●PIC

turbot larvae, could be involved in the viral devoid of food. Petechiae are observed degenerative changes, including acinar cell
transmission. in some viscera. Sometimes, food residue areas, and zymogen granules freeing. Nuclear
Similarly, it has been demonstrated that remains in the gut, the quantity is small and pyknosis of different sizes are observed. In
the freshwater crayfish confined to the far distal or rectal portion. many cases, inflamatory cell infiltration is not
(Astacus astacus) retains the virus in tissues Very often the body cavity may contain ascitic evident. In fish that suffered the disease up to
and hemolymph, constantly shedding the virus fluid. The stomach and anterior intestine con- two years before the histology study, hyper-
to the water. Halder and Ahne suggest that tains a clear to milky cohesive mucus, among trophy of Langerhans’ islets with abundant
these organisms are infected by the consump- other findings. fibrosis were found.
tion of IPNV-infected trouts. Main lesions found at In cases of pancreatic lesions, also acute
The following shellfish species are regard- the histopathology study enteritis featured by necrosis and sloughing of
ed as reservoirs of the IPNV: mussels (Mytilus include: focal coagulat- the epithelium are observed. In the intestinal
galloprovincialis), oysters (Crassostrea gigas), ive necrosis in pan- lumen, catarrhal whitish exudate is associated
periwinkles (Littorina littorea), and wild fish as creas, kidney and with the disease. Inclusion bodies are not
sand eels (Ammodytes sp), sprat (Sprattus intestine. The observed in affected cells. In many cases,
sprattus) and blue pancreatic tissue the renal tissue has small focal degenerative
showed changes. In fish that were infected during
early ages, abundant rounding up of epithelial
cells with karyorhectic nuclei was found. This
finding suggest that they can be viral replica-
tion sites in carrier fish; however, it has not
been confimed.

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whiting (Micromesistius
poutasou), among others. IPNV
has been also isolated from moist
fish pellets and marine sediments.
Wild piscivorous birds are regarded
as vectors of the IPNV, which can be
isolated from faeces samples.

Signs
The IPN is a typical disease in early ages
of salmonids, causing up to 100 percent of
mortalit y in fi ngerlings and fi rst-feeding
fry. An experimental study reported a mean
cumulative mortality ranging from 84 per-
cent to 92 percent in challenged Atlantic
salmon fry. The fish mortality started seven
days post-challenge and peaked at 10-12
days.
Generally affected fish showed anorexia
and rotate about their long axis in a whirling
motion with lapses of ataxia. In these fish
darkening occurs (hyperpigmentation). Mild
to moderate exophthalmia and abdominal
distention are common. Also, gills are typi-
cally pale and hemorrhages are sometimes
present in ventral areas, including the ventral
Aller Aqua A/S
fins. Many emaciated fish trail long, thin, Allervej 130, Aller
whitish, cast-like excretions from the vent. DK-6070 Christiansfeld
aller-aqua@aller-aqua.com
Tel. +45 7022 1910
Macroscopic and Fax +45 3841 2059
microscopic findings www.aller-aqua.com
According to necropsy findings, spleen,
heart, liver and kidneys of fry are abnormally
pale and the digestive tract is almost always


EXPERT T●PIC

fish, reduces the risk of infection. However, inactivated vaccines do not exist. Treatment
Diagnosis in Mexican trout farms, this condition is with formalin or ß-propiolactone for use in
The procedure for IPN diagnosis, recom- not always possible. As mentioned above, vaccines, completely inactivated IPNV, but
mended by the OIE, is based on the isolation Salgado-Miranda carried out the IPNV isola- caused a slight reduction in antigenicity up
of IPNV in susceptible cell lines (Figure 1), and tion from three rainbow trout breeding farms to 50 percent . An active vaccine containing
further identification by serological techniques located at Mexico State. an IPNV non-pathogenic strain, normal trout
by immunofluorescent test, neutralization test Obtained results indicated a possible serum-sensitive, did not confer protection in
and ELISA. horizontal transmission throughout the water experimental challenged fish.
Diagnosis of clinical outbreaks is based supply from a farm where a previous IPN In Norway, both inactivated and recom-
on histology and immunological ev idence outbreak in fry was recorded. In these cases, binant vaccines are widely used. The recom-
of the IPNV in infected tissues. These cases treatment of supplied water could decrease binant vaccine, the first one licensed for
are confirmed by the IPNV isolation and the risk of an IPN outbreak and other infec- using in fish, express the VP2 sequence in
immunological identification of the virus. Due tious agents. Liltved et al. experimentally Escherichia coli and induce specific IPNV
to insufficient knowledge of the serological exposed live cultures of Aeromonas salmo- antibodies.
responses of fish to IPNV infection, the detec- nicida subsp. salmonicida, Vibrio anguillarum, As it happens in other viral diseases, there
tion of fish antibodies to IPNV has not been V. salmonicida, Yersinia ruckeri and IPNV to is no treatment for the IPN. Several antiviral
accepted by the OIE (2003) as routine tests. ozone or ultraviolet (UV) irradiation at nine°- compounds inhibits the in vitro replication in
Detection of IPNV in cell lines is consist- 12°C. The four bacteria tested were inacti- cell culture; for example, ribavirin, pyrazofurin
ent and simple, particularly in cell lines from vated by 99.99 percent (fourlog reductions in and 5-ethynyl-1-ß-D-ribofuranosylimidazole-
homologous species. It is due to: 1) the virus viable count) within 180 seconds at residual 4-carboxamide (EICAR),among other com-
is present in high level titers in the tissues; 2) ozone concentrations of 0.15-0.20 mg/L. pounds. Research on EICAR as an antiviral
viral isolation could be positive from non-dis- The IPNV was inactivated within 60 sec- compound showed good results in experi-
onds at residual ozone concentrations of 0.10 mentally IPNV-infected rainbow trout.
a 0.20 mg/L. The effect of the administration of lys-
Similarly, the four bacteria tested were ozyme (KLP-602) in the feed of IPNV experi-
inactivated by 99.9 percent (five log reduc- mentally infected rainbow trout, has been also
tions in viable count) at a UV dose of 2.7 evaluated. Cumulative mortality was lower in
m Ws/cm2 at room temperature. IPNV was fish fed on dietary treatment containing lys-
much more resistant to UV irradiation than ozyme (30%), compared with untreated fish
the bacteria. An average UV dose of 122 m (65%). Based on the significant increase of all
Ws/cm2 was required for 99.9 percent (three the immunological parameters, these authors
log) reduction in virus titer. However, it has to refer that the lyzozyme modulated the cel-
be considered that ozone low residual levels lular and humoral defense mechanisms after
(0.010 a 0.20 mg/L) have also caused mortali- suppression induced by IPNV. Also, a selected
ties in trout recirculating systems. trout strain resistant to natural infection by
A concentration of 40ppm available chlo- this virus has been reported.
rine was required to experimentally inactivate As Håstein et al. pointed out, future
eased fish 3) viral isolation could be positive 10 TCID50 of IPN V/ml in 30 minutes. national and international aquaculture regula-
from any viral phase; 4) two to three weeks Similarly, a concentration of 35ppm of active tions for the establishment of preventive
are required for isolation and identification iodine was required to completely inactivate and control strategies of infectious diseases
of the agent, which is not a critical issue for 10 TCID50 of IPNV/ml in the same time. include: adoption of standardized control
presentation of a epizootic outbreak, and 5) Other studies, where several disinfectants methods, suitable infrastructures develop-
high sensitivity and easy observable cytopathic were tested, 25ppm of iodine was required ment, and a deeper comprehension of the
effect. Cell lines used for the IPNV isola- to inactivate IPNV, infectious haematopoyetic epizootiology of aquatic organism diseases.
tion include: RTG-2 (rainbow trout gonad), necrosis virus (IHNV) and viral haemorrhagic
CHSE-214 (chinook salmon embryo) and septicemia (VHS). Conclusion
BF-2 (bluegill fry). It is important to highlight that IHNV and IPNV is a birnavirus affecting mainly sal-
Currently, some methods have been VHS are exotic infectious agents in Mexico. monid species, being the rainbow trout the
developed for detecting IPNV by reverse For controlling IPN in breeding farms, infected most susceptible species. In Mexico, isolation
transcriptase-polymerase chain reaction fish and its offspring (eggs, fingerling and fry) and identification of this infectious agent
(RT-PCR) technique. However, sensitivity of have to be sacrificed. IPNV transmission by from rainbow trout was recently reported.
this technique has not been greater than the fertilized eggs can occur in spite of iodine Neither a treatment nor totally effective
cell culture. Hence, viral isolation and sero- treatment. Propagation of IPNV-free stocks vaccines against this disease are available,
logical confirmation of the virus are regarded monitored by viral isolation during several being the preventive and control measures
as the choice procedures for the IPNV years, has been a good strategy for the control of great importance. Introduction into farms
identification. of IPN in breeding farms. of eggs, fish and water supply free of IPNV
In areas where IPN is enzootic, it is recom- are the main preventive strategy. These also
Prevention and control mended, during an outbreak, to decrease the constitute the most important risk factors in
Current preventive methods are based on density of the affected population, reducing spreading of this disease.
the onset of control and hygiene practices the impact on the total mortality. A study
during rearing of salmonids, avoiding introduc- showed that interaction between fish density Acknowledgments
tion or importation of fertilized eggs or fish and number of infected fi sh, affected signifi
The collaboration in structure design and
from IPNV-infected breeding trouts. Also, cantly the mortality parameter. However, critical review of the manuscript by Dr. Edgardo
the use of fish-free freshwater (for exam- there are some disagreements about it. Soriano Vargas, CIESA-FMVZ-UAEM, is greatly
ple, spring water), particularly IPNV-carrier Up to date, highly effective IPNV- acknowledged.


8
IDL-IAF.pdf 1 5/8/12 9:58 AM
EXPERT T●PIC

THE 7TH
INDONESIA’S
NO.1
LIVESTOCK,
FEED, DAIRY
AND
FISHERIES
INDUSTRY
SHOW
"Food Education
Campaign"
Hosted by

Directorate General of Livestock
and Animal Health, Ministry of
Agriculture, Republic of Indonesia
C

Struggling extensively, by populating lakes and water
sources.
M

Y
Official Regional
Publication
Official Local
Publication

Downstream? By the 1980s, there was a new effort to
propel this activity through the construction
CM

MY

of fish farms in various mountainous prov- Supporting Publications
The trout value chain in Peru inces of the country. However, raising trout
CY

did not take off as an economic activity and CMY

by Jodie Keane with Alberto Lemma, the infrastructure that was constructed was K

based on studies by Juana Kuramoto at left underused.
GRADE, a member of the Consorcio de
Investigación Económica y Social (CIES), "The United States Agency
Peru.
International Aid project for Poverty

I
n Peru, the United States Agency Reduction and Alleviation (PRA)
International Aid (USAID) project for has been one of the pioneers of
Poverty Reduction and Alleviation
(PRA) has been one of the pioneers
value chain interventions. The chain
of value chain interventions. Under the for trout is one of the successful"
PRA, value chains of distinct products have
been fostered, ranging from agro-industrial In the 2000s, the Peruvian enterprise
products to artisanal goods and small manu- Piscifactoría Los Andes made important efforts
facturing, which have then gained placement to begin trout export to foreign markets.
in international markets. These efforts complemented the PRA project,
with the development of trout value chains
The chain for trout is one of the successful initiated in Junín, Huancavelica and Puno.
chains achieved by the PRA. Not only has it
combined the natural advantages of raising Linking producers to exporters www.indolivestock.com
www.sdticampaign.com
this fish in Peruvian territory, but also it has Although the initial investments required
managed to consolidate access to foreign for trout production may be low, export Organised by
markets through a national producer and of trout to international markets requires
trader, Piscifactoría Los Andes. a series of sanitary certifications, imposing
Raising trout has a long history in a high cost on producers and traders. The PT. NAPINDO MEDIA ASHATAMA
Jl. Kelapa Sawit XIV Blok M1 No.10, Billy & Moon,
Peru. The species was introduced in the value chain for trout is divided into three Pondok Kelapa Jakarta 13450, Indonesia
Tel: (62-21) 8644756/85 | Fax: (62-21) 8650963
country in the 1930s, with the import of well-determined links: fry production, trout E-mail: info@indolivestock.com

eggs and fry brought from the US. The production and marketing. These links define
development of trout farming occurred the principal actors in the value chain.


EXPERT T●PIC

One company in Peru accounts for the and overemphasis on the provision of basic
majority of trout exports (90 percent as of training to the neglect of other activities. The
2006) and is the largest and oldest within low prices that are prevalent in the region,
the industry in Peru. Piscifactoría Los Andes lack of credit, high levels of informality, lack
recognised that it would need to increase of coordination of the actions of state organs
production in order to begin exporting trout. and scant knowledge of marketing aspects of
In 2000, the company decided to participate trout are the main obstacles to the develop-
in the PRA project and initiated negotiations ment of this activity in Puno.
with producer organization, SAIS. The com-
pany would provide the necessary capital as Conclusions
well as purchasing the fry and balanced food. This study showed that value chain inter-
SAIS agreed to hand over its production to ventions should be utilized for programs
the company once the trout had reached the whose main objective is to increase the
optimal size and weight. The PRA financed the dynamism of economic activity in a specific
contracting of several experts, who provided territory, as such programs are not necessarily
technical assistance to SAIS. effective in alleviating poverty.
Despite initial incompliance on the part of In general, value chain interventions are
SAIS, the interaction allowed for Piscifactoría targeting foreign markets, which are subject
"There are several Los Andes to increase production and sell to to quality certification and sanitary norms
the export market. The agreement between that can present bottlenecks for small local
lessons to be learnt SAIS and Los Andes was broken, but the producers. Moreover, coordinating the chain
from this experience. coordination model must have appealed to the requires significant technical and financial
company because it continued to participate capacity. In the examples discussed, such
with the PRA in other regions. In fact, the assistance has been forthcoming from the
company has signed an agreement with private PRA, but project objectives have not always
First, coordination company California’s Garden de Oxapampa been achieved.
agreements need to be within the framework of a PRA project. It is important not only to provide technical
assistance, but also to offer access to finance and
put in place to facilitate The experience of Acoria to facilitate institutional development. Sensitisation
In this case, the coordination was between programs are recommended in order to promote
investments in public the formalization of producers and membership
the Municipality of Acoria and the Los
infrastructure; management Andes company. The agreement continues in associations, and to engender confidence and
to present day. In 2003, initial production respect in the agreements.
could be realised by a reached 12 metric tones of trout per year Poverty alleviation programs should be
and production is expected to reach 72 designed mainly to elevate basic poverty
municipal company or metric tones in 2008. In 2007, the municipal indicators, and not to coordinate with sophis-
by a company under a enterprise attained financial self-sufficiency ticated markets. Poor producers generally
and managed to generate employment for its manage a range of resources and activities
franchise agreement. community members (including single moth- in order to support themselves, and often
ers and widows). The Municipality of Acoria is consider focusing on a single economic activity
contemplating initiating trout farming in other to be a high risk.
Second, it is feasible to locations in its jurisdiction. In parallel with the promotion of value
There are several lessons to be learnt from chains that coordinate with foreign markets, it
replicate coordination this experience. First, coordination agreements is necessary to work on the formation of value
need to be put in place to facilitate invest- chains that coordinate with regional markets
models on a small scale, ments in public infrastructure; management and the domestic market, in order to prevent
but it is still necessary could be realised by a municipal company or prices falling from excess supply. To this end,
by a company under a franchise agreement. it is necessary to work on the formation of
to include components Second, it is feasible to replicate coordination regional markets and the provision of public
models on a small scale, but it is still necessary goods in the form of physical infrastructure
of technical assistance to include components of technical assistance and market information systems.
and financing. and financing. Third, expanding the level of The focus on demand promoted by the
production of trout requires significant capital. PRA project should be supported by the
The financial solvency of large producers and important activity of market intelligence. Only
coordinators is vital. in this way will we be able to construct stable
Third, expanding the level demand for local producers and ensure that
of production of trout The experience of Puno market prices are adequate in order to gener-
In Puno, there are different institutions ate sufficient utility to cover the risk that they
requires significant capital. linked to trout farming, such as strong produc- face for their specialization.
er associations like the Association of Trout
The financial solvency Producers (APT), which are relatively active in
More inforMation:
of large producers and promoting technical assistance projects for the
benefit of their associates. However, initiatives The full study is available in Spanish on the
coordinators is vital" have not managed to coordinate the value COPLA website:
http://www.cop-la.net
chain strongly, owing to budget limitations


TROUT
EXPERT T●PIC

INFO

Australian Trout & Salmon Farmers Association Peruvian Aquaculture Company
Mitch MacRae - Email: buxtontrout@bigpond.com informes@peruvianaquaculture.com
http://www.growfish.com.au/grow/pages/Site/Associations.htm http://www.peruvianaquaculture.com/

British Trout Association Turkey Central Fisheries Research Institute
David Bassett - Email: david.bassett@britishtrout.co.uk) info@sumae.gov.tr
http://www.britishtrout.co.uk http://www.sumae.gov.tr/en/

Polish Trout Breeders Association
Marcin Mikolajczak - mm@sprl.pl

Danish Aquaculture Association
Brian Thomsen - Email: brian@danskakvakultur.dk
http://www.danskakvakultur.dk/default.aspx?pageid=291

... TILAPIA
BE
ILL
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PIC

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Expert To

will be thet 2012 issue of
T EXPERT TO

Talapia /Augus
for the July al Aquafeed.
Internation
epting
rrently acc
We are cus for future articles
suggestion s - so if would likethe
and feature te please contact
NEX

u
to contrib Editor, Alice Neal,
Assoc iate .uk
rendale.co
alicen@pe
R
OU


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