May 2010
Pancreas Disease Success reported by Landcatch Natural Selection
Landcatch Natural Selection (LNS), the Scottish international salmon breeding company, has recently been getting recognition within the industry for the transfer of its award winning IPN resistance breeding success to its commercial stocks. This work, carried out in conjunction with The Roslin Institute, which cloned Dolly the sheep, led to the identification of genetic markers for a quantitative trait locus (QTL) which accounts for over 80% of the variation in IPN resistance. Fish with the resistant variant of the QTL have better survivability when exposed to IPN in freshwater or seawater. Every generation of Landcatch eggs and smolts are selected to have a resistance built-in at the IPN QTL. This is an industry first!
More recently the company has turned its attention to solving the problem of pancreas disease (PD), a very different condition. PD is primarily a chronic disease of the heart and skeletal muscles, although the pancreas is also affected. It is caused by an alphavirus. These viruses are more familiar in association with insect borne infections in man and animals but, of late, the PD alphavirus has become a severe problem to salmon farmers. The virus is believed to be transferred horizontally from fish to fish in the sea and can be responsible for major economic losses. In Norway for example, where it is particularly serious, losses in 2009 have been estimated to exceed $150 million.
A commercial vaccine has now been developed against the PD alphavirus, and it shows some level of protection although there are concerns about the duration of this. Using this expensive vaccine can still result in high mortalities in severely affected areas (80% is possible in the worst situation, although 20-40% is more normal). Since there is no suitable therapy, farmers generally have to resort to reduced feeding and careful, stress free, husbandry in the hope of nurturing a crop back to health. Apart from mortality losses, the resultant poor growth of survivors also affects final profit margins from the crop.
In view of the successes achieved with its IPN resistance selective breeding work, LNS has turned its efforts to PD resistance, to see what can be done to improve resistance to this disease in the Landcatch strain of salmon.
Working with PD is much more difficult than with IPN. Since it is a more chronic condition, with many fish suffering damage without dying, and since there is no good experimental infection model with clear-cut results, the normal means of testing siblings for resistance is not reliable. If field testing is used, there is no guarantee that there will be a natural outbreak at a particular site where trial stock are located, so this also is rather uncertain in output. Thus the Landcatch scientists, again working with colleagues in The Roslin Institute and in Ireland, have had to depend on field data from locations in which selected Landcatch fish have been placed where it is known that the disease can be expected to occur and where fish from other origins are also available for benchmarking against, in order to obtain comparative information on the success of the selected stock.
Initial studies were in Ireland, where there has been a long history of losses from the disease. Here an independent study indicated that there were significant differences in response to challenge by PD between the two most popular strains of salmon farmed in Ireland. Figure 1 shows typical results monitored and published by an independent group of scientists.
Click Here to See Figure 2
Figure 1. Comparative mortality of two strains of salmon in four PD outbreak sites
in Ireland in 2003-4. Strain B has been reported to be Landcatch.
Subsequently, in western Norway, where PD is now a very serious problem, smolts supplied by Landcatch were studied on a site in Austevoll. These fish were stocked in autumn of 2008 alongside PD vaccinated smolts from another source and once they had settled they showed the typical good growth pattern of Landcatch fish. During the following summer (2009), when fish were averaging 2kg and thus of very considerable economic value, PD struck the whole area. Fish went off feed, growth ceased and mortalities began to appear.
The Landcatch fish had NOT been vaccinated, which helped to ensure that any differential mortality demonstrated only the value of genetic enhancement and was unrelated to vaccination. The results were remarkable. Losses in Landcatch fish on the site were less than 5%. The mortality range across the adjacent cages, containing the fully vaccinated fish from another source, was between 15-40%.
Click Here to See Figure 2
Figure 2. Comparative mortality from pancreas disease on a Norwegian site where unvaccinated Landcatch smolts had been placed alongside vaccinated fish from a local source.
Unvaccinated Landcatch smolts have been placed in equally challenging PD environments in other areas of Norway over 3 years and each time have shown remarkably high levels of resistance to infection and very low, or indeed no, resultant mortality. LNS collaborates with experts in virology such as Dr David Graham of the Northern Ireland Veterinary Institute, where the PD virus was first isolated and world renowned research institutions such as The Roslin Institute to investigate genetic resistance to virus infection. Identification of quantitative trait loci (QTLs) associated with resistance to PD and their use in breeding will further enhance the high level of resistance observed in Landcatch stock. This process was pioneered by LNS for IPN resistance. Landcatch are continuously looking to add resistance for specific diseases such as PD to the range of traits that are taken into account as part of our individual broodstock fish selections. If QTLs for PD resistance are found, then it will be possible to further increase inherent genetic resistance to PD at every subsequent generation of the four-year breeding cycle.
In the meantime, however, commercial eggs and smolts, derived from the families with the same genetically enhanced resistance to viral disease observed in the Landcatch stocks at Hordaland are now available from Landcatch, and while PD is not yet conquered, field data to date indicate that using Landcatch stock, along with the PD vaccine, can be expected to significantly reduce losses from this scourge, even while the scientists seek the specific QTL(s) that will allow much greater accuracy for individual broodstock selection.
For further information please contact:
Alan Stewart on +44 (0)7767380234 May 18 2010
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October 2008
Landcatch health policy is planned and proactive
A commitment to stringent standards of fish health management and biosecurity are essential for anyone seeking to establish and maintain a sustainable and successful aquaculture business.
This was the message delivered in Chile on October 9 by Dr Marianne Pearson, head of veterinary services at Landcatch.
“An integrated approach to fish health management and biosecuity is required to control fish disease, both on-farm and at a national level.,” she told delegates to the International Seminar “Sanitary Aspects Critical in the Production of Salmon in Chile” held in Puerto Montt, Chile. “There are, however, no margins for error in combating global diseases and related health issues, particularly if we’re to realise our potential as a major food source for the future.”
Focusing primarily on broodstock health management and biosecurity operations in her own company, Landcatch, Dr Pearson pointed out that the foundations of national fish disease controls in Scotland were established as long ago as 1937. Since then, new business orders and regulations, many of which come from EU headquarters in Brussels, have been passed at regular intervals to create the highly structured disease control framework which governs aquaculture in Scotland today.
“The maintenance of Landcatch broodstock health standards is, in many ways, a microcosm of what happens at a national level,” she said. “Our on-farm approach is shaped by adherence to EU legislation, UK legislation, national surveillance programmes and a voluntary industry code of good practice. In addition, we have created the Landcatch veterinary health plan and biosecurity initiatives which form the basis of our system of health monitoring at farm level.
“As a business, we are planned and proactive in our approach to fish health management. We take the view that aquaculture businesses cannot afford to be merely reactive to an ever changing environment of existing and emerging diseases.
“Applying this philosophy to our business in a practical manner, our fish health calendar and biosecurity activities, are all geared to minimise the risk of disease introduction to our breeding base at Ormsary in Argyll, or any of our production units, This is essential for our continued success as a recognised international provider of salmon germplasm.
“We are also committed to minimising the impact of disease by making sure we’re developing the Landcatch strain of salmon to be resistant to disease challenges such as IPN, PD and SRS, which are all too commonly faced by fish farmers today.”
June 2008
Harvest weights averaging an impressive 5 kilos have been achieved by Landcatch-bred salmon on-grown by Lingalaks at their Sltkjelen site in Hardanger Fjord, close to Bergen.
Delivered to Lingalaks during late March and early April last year as 96-gram smolts, the stock were harvested in early June this year at an average weight of 5 kilos. This is an excellent result for Rolv Haugarvol in a part of Norway which has often been blighted by pancreas disease.
May 2008
Freedom Foods renewal
All Landcatch production sites in Scotland have successfully had their certificates renewed for the Freedom Food farm assurance and food labeling scheme monitored by the RSPCA.
“We applied for and achieved Freedom Food status for the first time last year,” said Neil Manchester, Landcatch Operations Director. “Our customers appreciate the welfare assurances associated with Freedom Food and we’re delighted to be entering our second year of fully approved status.”
Landcatch also has GLOBALGAP approval, a private sector scheme covering voluntary standards for the certification of agricultural products around the globe. GLOBALGAP is designed to reassure consumers about how food is produced, not only in minimizing detrimental environmental impacts, such as reducing the use of chemicals, but also ensuring a responsible approach to both health and safety and animal welfare.
May 2008
The 21st and 22nd of May saw a welcome return of the UK aquaculture Industry get-together in Aviemore. The first AquacultureUK exhibition was held at the MacDonald Aviemore Highland Resort in three exhibition halls. Landcatch and Landcatch Natural Selection were present and hosted a prize draw in aid of the Sandpiper Trust. The draw was made on Thursday 22nd May and the prize winners were as follows:
Lakeland Ltd. Two Virgin Atlantic air tickets – London to New York return.
Ms Gillian Rodger. One night dinner bed and breakfast for two people plus Spa day at the Highland Resort.
Miss Kate Lithgow. Salmon fishing for four rods on the River Teith at Lanrick.
Fish Farmer Magazine. A shooting experience for two people at Rothiemurcus Estate
Mr. Mike Newstead. A meat hamper from Ormsary Estate
Marine Harvest Ltd. A smoked salmon from Glenfeshie Seafoods
The Sandpiper Trust is a great cause and the charity trustees are extremely grateful to members of our Industry and others who have generously donated over £2,000 in raffle ticket receipts. Landcatch Ltd would like to add a note of thanks to everyone who supported the prize draw.
