Effects of dietary n?3 polyunsaturated fatty acids on lipid and fatty acid composition and haematology of juvenile Arctic charr Salvelinus alpinus (L.) |
| |
| Authors: | X Yang J L Tabachek T A Dick |
| |
| Institution: | (1) Department of Zoology, University of Manitoba, Winnipeg, Manitoba, Canada, R3T 2N2;(2) Department of Fisheries and Oceans, Freshwater Institute, 501 University Crescent, Winnipeg, Manitoba, Canada, R3T 2N6 |
| |
| Abstract: | The effect of dietary n−3 and n−6 polyunsaturated fatty acids (PUFAs) on juvenile Arctic charr Salvelinus alpinus (L.) were investigated with respect to essential fatty acid (EFA) deficiency and lipid metabolism using one commercial and
12 casein-based test diets. Arctic charr with mean weight of 1.6g were fed test diets for 12 weeks at 10°C. At the end of
the feeding, blood, liver, muscle and whole fish were sampled to determine haematocrit, haemoglobin, water content, lipid
and fatty acid composition. Charr fed diets containing 0–1.0% n−3 PUFAs showed typical EFA deficiency signs: fatty liver or
elevated water content in whole body or substantial accumulation of 20:3n−9 in liver polar lipids. These signs were less apparent
or disappeared when charr were fed diets containing ≥ 2.0% 18:3n−3. No correlation was found between dietary PUFAs and haematocrit
or haemoglobin values. Significant changes in fatty acid composition of liver polar lipids in charr fed dietary PUFAs indicate
that charr can convert 18:3n−3, 18:2n−6 and 20:5n−3 into long-chain PUFAs. While charr had a direct incorporation of dietary
22:6n−3 into liver and muscle there appears to be preferential utilization of n−3 PUFAs for elongation and desaturation. The
conversion of 18:4n−3 was less in muscle than in livers. These findings, combined with data on growth and feed efficiency
reported previously by Yang and Dick (1993), indicate that charr require 1−2% dietary 18:3n−3 (dry weight). Small amounts
of dietary 18:2n−6 (up to 0.7%) did not have detrimental effects on charr. |
| |
| Keywords: | Arctic charr diet haemoglobin haematocrit lipids metabolism polyunsaturated fatty acids desaturation desaturase |
| 本文献已被 SpringerLink 等数据库收录！ |
|
