Essential fatty acids in Atlantic salmon: effects of increasing dietary doses of n-6 and n-3 fatty acids on growth, survival and fatty acid composition of liver, blood and carcass.

Atlantic salmon fry (4 g) were fed for 4 months on semi-synthetic diets containing fatty acid methyl esters of either 18:2 n-6, 18:3 n-3 or a mixture of equal amounts of 20:5 n-3 and 22:6 n-3. The different amounts of polyunsaturated fatty acids added were 0, 0.1, 0.2, 0.5, 1 and 2% (by dry weight). Increasing levels of dietary n-3 fatty acids up to 1% gave faster growth rates in salmon fry, and fish fed the mixture of 20:5 n-3 and 22:6 n-3 seemed to grow faster than fish fed only 18:3 n-3. No significant effect on growth rate was seen when the dietary level of 18:2 n-6 was increased. Dietary inclusions of n-3 fatty acids reduced the mortality of salmon, while dietary 18:2 n-6 had no such beneficial effects. The dietary treatments caused substantial changes in the fatty acid composition of blood and liver phospholipids (PL), whereas the total lipid fraction of the carcass was less affected. Increasing doses of 18:2 n-6 in the diet resulted in an increased percentage of 20:4 n-6 in liver and blood PLs, while the percentage of 20:3 n-9 decreased. The percentage of 18:2 n-6 also increased in liver, blood and carcass. Dietary 18:3 n-3 resulted in increased percentages of 18:3 n-3 and 20:5 n-3 in liver PLs, while the percentage of 20:3 n-9 decreased. There was, however, no significant increase in the percentage of 22:6 n-3. Dietary 18:3 n-3 produced no significant changes in the composition of blood fatty acids, but increased the percentage of 18:3 n-3 in the carcass. The dietary combination of the n-3 fatty acids 20:5 and 22:6 resulted in an increased percentage of 22:6 n-3 in blood and liver lipids and a decreased percentage of 20:3 n-9, but there were no changes in the percentage of 20:5 n-3.

[1]  Thomassen,et al.  Essential fatty acids in Atlantic salmon: time course of changes in fatty acid composition of liver, blood and carcass induced by a diet deficient in n-3 and n-6 fatty acids. , 2000 .

[2]  M. Spira,et al.  Lifetime energy budget in the sea hare Aplysia oculifera , 1996 .

[3]  J. G. Bell,et al.  Induction of Δ9-fatty acyl desaturation in rainbow trout (Oncorhynchus mykiss) liver by dietary manipulation , 1996 .

[4]  J. G. Bell,et al.  Requirement criteria for essential fatty acids , 1995 .

[5]  J. Bézard,et al.  The metabolism and availability of essential fatty acids in animal and human tissues. , 1994, Reproduction, nutrition, development.

[6]  T. Dick,et al.  Effects of dietary fatty acids on growth, feed efficiency and liver RNA and DNA content of Arctic charr, Salvelinus alpinus (L.) , 1993 .

[7]  B. March.  Essential fatty acids in fish physiology. , 1993, Canadian journal of physiology and pharmacology.

[8]  J. G. Bell,et al.  Dietary sunflower, linseed and fish oils affect phospholipid fatty acid composition, development of cardiac lesions, phospholipase activity and eicosanoid production in Atlantic salmon (Salmo salar). , 1993, Prostaglandins, leukotrienes, and essential fatty acids.

[9]  T. Refstie.  Application of breeding schemes , 1990 .

[10]  T. Takeuchi,et al.  Requirement of juvenile red seabream Pagrus major for eicosapentaenoic and docosahexaenoic acids. , 1990 .

[11]  M. Thomassen,et al.  Different fats in feed for salmon: Influence on sensory parameters, growth rate and fatty acids in muscle and heart , 1989 .

[12]  B. G. Hughes,et al.  Human absorption of fish oil fatty acids as triacylglycerols, free acids, or ethyl esters. , 1988, Biochemical and biophysical research communications.

[13]  M. Crawford,et al.  Differential oxidation of saturated and unsaturated fatty acids in vivo in the rat , 1987, British Journal of Nutrition.

[14]  T. Storebakken,et al.  Growth rate estimates for cultured Atlantic salmon and rainbow trout , 1987 .

[15]  Irene Mueller-Harvey,et al.  Lipid biomarkers in marine ecology , 1987 .

[16]  D. Tocher,et al.  The lipid composition and biochemistry of freshwater fish. , 1987, Progress in lipid research.

[17]  K. Bjerve,et al.  Alpha-linolenic acid deficiency in patients on long-term gastric-tube feeding: estimation of linolenic acid and long-chain unsaturated n-3 fatty acid requirement in man. , 1987, The American journal of clinical nutrition.

[18]  J. Mead,et al.  Distribution of Fatty Acids in the Tissue Lipids , 1986 .

[19]  R. J. Henderson,et al.  Chain-length specificities of mitochondrial and peroxisomal beta-oxidation of fatty acids in livers of rainbow trout (Salmo gairdneri). , 1985, Comparative biochemistry and physiology. B, Comparative biochemistry.

[20]  Takeshi Watanabe.  Lipid nutrition in fish , 1982 .

[21]  R. R. Brenner,et al.  Nutritional and hormonal factors influencing desaturation of essential fatty acids. , 1981, Progress in lipid research.

[22]  W. Yamanaka,et al.  Essential fatty acids deficiency in humans. , 1980, Progress in lipid research.

[23]  T. Takeuchi,et al.  Requirement for essential fatty acids of chum salmon (Oncorhynchus keta) in freshwater environment. , 1979 .

[24]  R. Sinnhuber,et al.  Effect of dietary ω3 and ω6 fatty acids on growth and feed conversion efficiency of coho salmon (Oncorhynchus kisutch) , 1979 .

[25]  R. Sinnhuber,et al.  Growth response of rainbow trout (Salmo gairdneri) to dietary ω3 and ω6 fatty acids , 1976 .

[26]  C. Ogino,et al.  Requirement of Rainbow Trout fot Essential Fatty Acids , 1974 .

[27]  C. Ogino,et al.  Effect of Dietary Methyl Linolenate on Growth of Rainbow Trout , 1974 .

[28]  R. Sinnhuber,et al.  Essential fatty acids in the diet of rainbow trout (Salmo gairdneri): lipid metabolism and fatty acid composition. , 1972, The Journal of nutrition.

[29]  R. Sinnhuber,et al.  Essential fatty acids in the diet of rainbow trout (Salmo gairdneri): physiological symptoms of EFA deficiency. , 1972, The Journal of nutrition.

[30]  R. Sinnhuber,et al.  Essential fatty acids in the diet of rainbow trout (Salmo gairdneri): growth, feed conversion and some gross deficiency symptoms. , 1972, The Journal of nutrition.

[31]  G. Waller,et al.  Dimethoxypropane Induced Transesterification of Fats and Oils in Preparation of Methyl Esters for Gas Chromatographic Analysis. , 1964 .

[32]  J. Folch,et al.  A simple method for the isolation and purification of total lipides from animal tissues. , 1957, The Journal of biological chemistry.