Feed for aquaculture is growing at about 17%, according to the most recent Alltech’s annual Global Feed Tonnage Survey, to reach 40.4 million metric tons in 2013. Asia was the dominant region, accounting for 77% of the total market. Europe is a long way behind in second with 9.4%, followed by Latin America with 7.4%.
Fish oil is a critical lipid source in feeds for aquaculture, but severe pressure from a number of industries including nutraceutical, pharmaceutical, and aquaculture is pushing R&D professionals to remove fish meal and fish oil from fish feed.
“Several different terrestrial oilseeds are commercially used in fish feeds,” explained Stefanie Hixson and Christopher Parrisha from Memorial University of Newfoundland, and Derek Anderson from Dalhousie University, “however only a small proportion of fish oil can be replaced by these alternative oils due to their lack of long chain omega-3 polyunsaturated fatty acids.
“The ideal fish oil replacement should have a fatty acid composition that is highly digestible and should also provide high levels of precursor omega-3 fatty acids for biosynthesis of long chain omega-3 polyunsaturated fatty acids and low levels of omega-6 PUFA to maintain a high omega-3 to omega-6 ratio which is beneficial for fish and human health.”
One such vegetable oil to fit these criteria is camelina oil, which contains about 30% ALA (alpha-linolenic acid) and low omega-6 levels, and Hixson, Parrisha, and Anderson report the effects of using camelina oil as a full fish oil replacement for Atlantic salmon – the first study of its kind.
The data, published in the journal Food Chemistry, indicated that camelina oil and meal may have potential to replace fish oil and fish meal, but perhaps not at all lifestages: Results indicate it may be an effective strategy for Atlantic salmon during their the juvenile and grow-out phase.
Hixson, Parrisha, and Anderson examined the effect of replacing 100% of fish oil with camelina oil, as well as the effect of partial replacement of fish meal with camelina meal at a level of 10%.
The results indicated that, after 16 weeks of feeding, there were no differences between the camelina and control groups for weight and growth for the oil replacement group only, and, importantly, there were no difference in sensory quality of salmon fillets for the fish oil or camelina oil diets.
However, weight and growth rate were lower when fish meal was partially replaced by 10% camelina meal.
“It is questionable whether both camelina oil and specifically camelina meal cannot support growth, or whether other plant protein sources may be more suitable to include with camelina oil,” wrote the researchers.
“This data lends itself to a growing list of possible vegetable sources that may be used to replace fish oil.”
This study was supported by Genome Atlantic, Atlantic Canada Opportunities Agency – Atlantic Innovation Fund, and Research and Development Corporation of Newfoundland.
Source: Food Chemistry
Volume 157, Pages 51-61, doi: 10.1016/j.foodchem.2014.02.026
“Full substitution of fish oil with camelina (Camelina sativa) oil, with partial substitution of fish meal with camelina meal, in diets for farmed Atlantic salmon (Salmo salar) and its effect on tissue lipids and sensory quality”
Authors: S.M. Hixson, C.C. Parrish, D.M. Anderson