Robust fish: Feed for cardiovascular health of salmonids

Viral cardiac diseases pose serious threat to Norwegian salmonid industry. The prevalence of viral cardiac diseases has been increased in farmed Atlantic salmon during recent years. To date, no in vitro tests are available for heart diseases in Atlantic salmon. However, challenge studies are possible but costly, require special labs and may result in inconsistence results. Although there is limited information regarding functional effects of viral diseases in the heart where the heart is one of the primary targets. Relating pathology to physiology is surprisingly challenging. However, relation between cardiovascular health and swimming performance has been established in salmonids such as rainbow trout and Atlantic salmon. The purpose of the study is to investigate whether nutrients addition in regular feed beyond the need for optimal growth of salmonids can enhance the cardiovascular health, swimming performance, fish welfare and feed intake. This is achieved by feeding different diets and document fish cardiovascular health by swimming tests. Expected distress for the animal is minimal. Fish will be quickly recovered or humanely sacrificed post fatigued. This non-lethal method will reduce the number of animals sacrificed for terminal samplings to document health status of the fish as practiced at farms. This work will reduce poor fish growth, provide robust fish with enhanced immune responses, fewer outbreaks of disease and thus reduce mortality. A diet that can support cardiovascular health and provide better animal welfare and eventually reduced risk of outbreaks and mortality, as well as increased financial gain and better reputation for the aquaculture industry. Total 344 Atlantic salmon and 140 rainbow trout will be used over the period of 2 years. No cardiac cell lines or in vitro tests for salmonids available to date. For cardiovascular health assessment and swimming tests on salmonid, live animals must be used, however, the number used in the experiment is limited to that which will provide significant differences between control and experimental groups (assuming an alpha value of 0,05 and a power of 0,8).