November | December 2012

An overview of the UK fish vaccination industry

The International magazine for the aquaculture feed industry

International Aquafeed is published five times a year by Perendale Publishers Ltd of the United Kingdom.All data is published in good faith, based on information received, and while every care is taken to prevent inaccuracies, the publishers accept no liability for any errors or omissions or for the consequences of action taken on the basis of information published. ©Copyright 2012 Perendale Publishers Ltd. All rights reserved. No part of this publication may be reproduced in any form or by any means without prior permission of the copyright owner. Printed by Perendale Publishers Ltd. ISSN: 1464-0058

I am sure everyone involved in any fish vaccination would really rather prefer that they didn’t have to vaccinate. It is an expensive, time consuming, hazard-

ous and stressful process. So why do we vaccinate fish?

Certainly in the salmon faming Industry, it has become a part of the freshwater produc-tion process for many years now and it is only some of the ‘most mature’ members of the salmon industry remember what it was like before oil-based vaccines were developed.

Prior to these effective oil-based vaccines, salmon producers could be expected to loose maybe 50 percent of their stocks to the main disease threat, Furunculous. Some farms suf-fered more than others but all had problems of some form or other. The only real solution was treatment with antibiotics, which was not only extremely expensive but led to problems with resistance.

The other problem was the negative public perception of high usage of antibiotics in a food animal. This, in conjunction with a few high profile cases of use of unlicensed antibiotics on fish farms, led to the industry seeking a fresh approach to disease manage-ment. The oil-based vaccines used today in the aquaculture industry are all ‘multivalent’, meaning they prevent a variety of diseases, a bit like the MMR vaccine in humans.

Why vaccinate?Economics, logistics and risk involved

in injection mean that many alternative approaches have been tried. Dip vaccines and in-feed vaccines have all been trialled but due to the nature of how fish immune systems work, these only have limited effects. If it were that easy, I am sure human would prefer to have a tablet instead of an injection when they go on holiday!

The problem with putting vaccines ‘in-feed’ is that the in order for vaccines to work they need to create a response in the immune system - the body has to ‘react’ to a foreign substance in the body to produce

the antigens to give the immune system the correct defences. If the substance that creates this reaction in the body is put into the feed, the body is designed to deal with this by digesting and excreting it through the digestive system, and it does not stimulate the immune system and thus has no effect in preventing disease.

Who vaccinates?The Atlantic salmon industry through-

out the world has been familiar with intra-peritoneal (by injection) vaccinations for many years. Trout farmers occasionally vaccinate for Enteric Redmouth Disease (ERM) on high-risk sites but because the production cycle is much quicker for trout than salmon, most disease can be managed through dip vaccination.

The sea-bass industry in the Mediterranean is a big growth area at the moment but is suffering in the same way salmon farmers did 25 years ago with many sites loosing maybe 50 percent of their stocks. Recent com-mercial production of an effective oil-based vaccine have led to many sea bass farmers now considering vaccination by injection as the only effective method to control disease. Those few that have invested in a vaccination strat-egy have seen big financial benefits from it and as word spreads, it is likely to become commonplace in this industry too.

How is the procedure carried out?

The fish are starved for 24 or 48 hours (depending on time of year) prior to vac-cination to empty the gut. The fish are then crowded in the tank or cage before being pumped or hand netted into an anaesthetic bath. The fish take one to two minutes to become fully anaesthetised. This is extremely

am sure everyone involved in any fish vaccination would really rather prefer that they didn’t have to vaccinate. It is an expensive, time consuming, hazard-

ous and stressful process. So why do we

Certainly in the salmon faming Industry, it has become a part of the freshwater produc-tion process for many years now and it is only some of the ‘most mature’ members of the

the antigens to give the immune system the correct defences. If the substance that creates this reaction in the body is put into the feed, the body is designed to deal with this by digesting and excreting it through the digestive system, and it does not stimulate the immune system and thus has no effect in preventing disease.

Who vaccinates?

How is the procedure carried out?

The fish are starved for 24 or 48 hours (depending on time of year) prior to vac-cination to empty the gut. The fish are then crowded in the tank or cage before being pumped or hand netted into an anaesthetic

An overview of the UK fish vaccination industryby Kathy Taylor, Salmovac, UK

Melanisation (a permanent ‘bruise’ like mark in the flesh of the fish) causing downgrades at harvest.

Permanent damage and scarring inside the fish due to damage by needle movement during vaccination process.

10 | InternatIonal AquAFeed | november-December 2012

FEATURE

november-December 2012 | InternatIonal AquAFeed | 11

IAF12.06.indd 10 07/11/2012 17:39

important for vaccinator safety but also the safety and welfare of the fish.

The fish are then delivered onto a stainless steel table where the fish then are vaccinated in a very specific area, with only a 3 mm toler-ance. The team must achieve a 96 percent accuracy target and considering most vaccina-tors handle between 15-20,000 fish each this is quite some achievement!

The fish are then returned to a recovery tank and should come round from the anaes-thetic within about two to three minutes. There is always some level of mortality after this high risk, stressful process but usually it is just a few fish, around 100 for every 100,000 fish vaccinated. High mortalities immediately after vaccination are usually attributed to poor anaesthesia rather than the injection.

The consequences of poor vaccination usually only become apparent months after vaccination and can last up until harvest where the financially consequences become appar-ent. The main problems are:

Incorrect needle depth resulting in either intra-muscular injection (needle too short) or internal organ damage, including granuloma (needle too long) which results in the fish not growing properly due to damage to the gut.

Fish not being immune to the disease because of incorrect dosage (or no vaccine) being delivered.

Two of the main problems Salmovac

encounters as a contract vaccina-tion team, is poor anaesthesia of the fish and also poor grading, prior to vac-cination of the fish. Poor anaesthesia of the fish can lead to high mortalities. If fish are under anaes-thetised, the whole process becomes stressful and danger-ous for them (imag-ine having a major operation whilst only partly sedated!). On the other hand, if they are over anaesthetised, they risk not recover-ing quickly enough, resulting in piles of fish in the recovery tank causing suffoca-tion or even worse, not recovering at all.

The other risk factor here is to the vaccinators. If the mineral oils used in

10 | InternatIonal AquAFeed | november-December 2012 november-December 2012 | InternatIonal AquAFeed | 11

FEATURE

For more information: contactlfa@lesaffre.fr

Wellbeing, the source of performance

Consistent products supported bythe Lesaffre group experience andits unique know-how in biotechnologyand nutrition;

Selected strains and controlled production;

Designed to solve nutritional and sanitary issues;

Dedicated range of products:live yeast, yeast cell wall, yeast extractand enriched yeast.

For more information: contactlfa@lesaffre.fr

Innovative and proven yeast products in aquaculturein aquaculture

Wellbeing, the source of performance

Consistent products supported bythe Lesaffre group experience andits unique know-how in biotechnologyand nutrition;

Selected strains and controlled production;

Designed to solve nutritional and sanitary issues;

Dedicated range of products:live yeast, yeast cell wall, yeast extractand enriched yeast.

C

M

Y

CM

MY

CY

CMY

K

ridgewaybio_quarterpage_print.pdf 1 29/10/2012 13:57

IAF12.06.indd 11 07/11/2012 17:40

the vaccines are accidentally injected into the finger, the vaccinator will require urgent medi-cal attention. The finger will have to be cut open and the vaccine flushed out, otherwise the resulting inflammation could result in the blood supply to the finger tissues being reduced and possible loss of the digit.

How has vaccination developed?When the first oil-based vaccines became

available for the salmon industry, quite a few companies started vaccinating their own fish believing (mistakenly) that this would keep costs down, as they wouldn’t have to contract in extra labour. The problems

encountered and the sometimes devastating results of this quickly led to most companies employing contract vac-cination specialists.

The main problems were a lack of knowl-edge about needle depths and the results of inaccurate vaccina-tion, along with the process taking a long time because of the inexperience and slow-ness of untrained vac-cinators. An inexperi-enced team of six could probably manage to vaccinate between 150-200,000 fish a week where as our teams can do 400-500,000 fish a week!

Vaccines have devel-oped tremendously in the past 20 years, the dose per fish used to be 0.2 ml and the vaccines were very thick, difficult to administer and causes high side effects in the fish. They are now 0.1 ml and much thinner and cause fewer side effects. Some of the newer vac-cines are now a 0.05 ml dose and again have reduced side effects for the fish while also giv-ing increased protection against disease.

The improvements in vaccine technology have not only reduced the side effects for the fish but have also improved the ease of use for vacci-nators. The smaller dose size is much easier to

administer, resulting in fewer cases of repeti-tive stress injury and carpel tunnel syndrome.

Which species are worth vaccinating?

All species are worth vaccinating if the eco-nomics of preventing disease rather than treating it stack up. With the salmon industry, it is essen-tial that all fish are vaccinated and as the sea bass industry expands and improves it is likely that all sea bass will have to be vaccinated to. The key to whether it is worth vaccinating or not, relies on whether then is an effective vaccine at a price that makes it viable to vaccinate and prevents the lost of market size fish to disease.

How does vaccination provide value for money?

The expense and hassle of vaccination is far outweighed by potential losses at sea or the heavy costs and logistics involved with treating fish at sea. The other factor to bear in mind is fish welfare and the associated regulations. Most Scottish salmon farms now subscribe to the RSPCA ‘freedom foods’ standard, which lays down welfare standards for the aquaculture industry and vaccination plays a key role in this. It costs a few pence to vaccinate a smolt at 30 g but the price of losing a market size salmon to a preventable disease is many, many times that amount. Prevention is not only preferable, but finan-cially essential, to cure.

Vaccination in action at Salmovac

The fish are delivered onto a stainless steel table where the fish are vaccinated in a very specific area, with only a 3 mm tolerance. The team must achieve a 96 percent accuracy target and considering most vaccinators handle between 15-20,000 fish each this is quite some achievement!

About the authorSalmovac was founded in 2003 in

the north of Scotland in response to a growing demand for quality contract vaccination services within the Scottish salmon industry. The directors, Kathy and John Foster both had had previous vaccination experience and a wealth of knowledge of both fish health and aquaculture practices along with a back-ground in quality and business systems. They started with just one team of five people and successfully vaccinated five million salmon in the first year. Because of the high quality and professional-ism delivered by Salmovac, word soon spread and contracts came flooding in. However, they were careful not to over stretch themselves in the first few years, preferring to increase the business at a sustainable rate, in order to keep the quality of service and reputation of the company high.

As a result of this sustainable growth of the business, they currently employ over 40 people from all over the world and successfully vaccinated 60 million fish last season!

In 2010, Kathy Foster (now Taylor) purchased the business from her ex-husband and now is the sole director of Salmovac. What was a difficult time for the business back then has proved to be a benefit for the longer term and the business has continued to grow and prosper with contracts not only in Scotland but also in Ireland, Norway, Spain, France and Switzerland.

More InforMatIon:Kathy Taylor, SalmovacTel: +44 1381 621914Email: Kathy@salmovac.comWebsite: www.salmovac.com

12 | InternatIonal AquAFeed | november-December 2012

FEATURE

No hollow spaces | No cross contaminationExcellent cleaning access | Filtered air inletTemperature control | Moisture control | Cleaning in Place

C L E A N C O N T R O L

Swivel Valve Cooler MkII

c o o l a n d d r y

clean and lean

info@geelencounterflow.com

www.geelencounterflow.com

T +31-475-592315

Geelen Counterflow Holland / USA / Argentina / China

IAF12.06.indd 12 07/11/2012 17:40

12 | InternatIonal AquAFeed | november-December 2012

No hollow spaces | No cross contaminationExcellent cleaning access | Filtered air inletTemperature control | Moisture control | Cleaning in Place

C L E A N C O N T R O L

Swivel Valve Cooler MkII

c o o l a n d d r y

clean and lean

info@geelencounterflow.com

www.geelencounterflow.com

T +31-475-592315

Geelen Counterflow Holland / USA / Argentina / China

IAF12.06.indd 13 07/11/2012 17:40

www.aquafeed.co.uk

LINKS

• Seethefullissue• VisittheInternationalAquafeedwebsite

• ContacttheInternationalAquafeedTeam

• SubscribetoInternationalAquafeed

VOLUME 15 I S SUE 6 2 012

THE INTERNATIONAL MAGAZINE FOR THE AQUACULTURE FEED INDUSTRY

An overview of the UK fish vaccination industry

Why check selenomethionine levels in selenium yeast?

Extrusion technology for the production of micro-aquatic feeds

and shrimp feeds

EXPERT TOPIC– Salmon

IAF12.06.indd 1 07/11/2012 17:39

Thisdigitalre-printispartoftheNovember|December2012editionofInternationalAquafeedmagazine.Contentfromthemagazineisavailabletoviewfree-of-charge,bothasafullonlinemagazineonourwebsite,andasanarchiveofindividualfeaturesonthedocstocwebsite.Pleaseclickheretoviewourotherpublicationsonwww.docstoc.com.

Topurchaseapapercopyofthemagazine,ortosubscribetothepapereditionpleasecontactourCirculationandSubscriptionsManageronthelinkabove.

INFORMATIONFORADVERTISERS-CLICKHERE