Rosenlund G, Torstensen BE, Stubhaug I, Usman N, Sissener NH. Atlantic salmon require long-chain n-3 fatty acids for optimal growth throughout the seawater period.
J Nutr Sci 2016;
5:e19. [PMID:
27293556 DOI:
10.1017/jns.2016.10]
[Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 03/02/2016] [Indexed: 12/28/2022] Open
Abstract
The nutritional requirement for n-3 long-chain PUFA in fast-growing
Atlantic salmon (Salmo salar) during grow out in the sea is not well
documented. Diets were formulated with levels of EPA (20 : 5n-3) and DHA
(22 : 6n-3) ranging from 1·3 to 7·4 % of fatty acids (4–24 g/kg feed).
Two long-term trials were conducted through the seawater phase, the first at 6 and 12°C,
and the second at 12°C. In the first trial, growth at both temperatures was significantly
lower in fish fed 1·4 % EPA+DHA of total fatty acids compared with the 5·2 % EPA+DHA
group. In the second trial, growth was significantly lower in fish fed 1·3 and 2·7 %
compared with 4·4 and 7·4 % EPA + DHA. Fatty acid composition in the fish reflected diet
composition, but only after a 7-fold increase in body weight did the fatty acid profile of
the fish stabilise according to dietary fatty acids (shown for EPA and DHA). The retention
efficiency of DHA increased with decreasing dietary levels, and was 120–190 and 120–200 %
in trials 1 and 2, respectively. The retention efficiency of EPA was lower (60–200 %), and
values >100 % were only achieved at the lowest dietary levels in both trials.
Temperature did not affect fatty acid retention efficiency. These results suggest that
Atlantic salmon have a specific requirement for EPA + DHA >2·7 % of fatty acids for
optimal long-term growth in seawater, and that short-term growth trials with less weight
increase would not show these effects.
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