Comparative characteristics of the fatty acid composition of lipids in factory and wild juveniles of Atlantic salmon <i>Salmo salar</i>
Differences between a factory and a wild juvenile salmon (fingerlings at the 0+ age and 1+ parrs) were shown in the content of physiologically significant fatty acids and their ratios. Factory juveniles (age 0+ and 1+) have a very low content of a physiologically significant 18:3 n -3 and 20:4 n -6 fatty acids compared with the wild individuals, whereas relatively high amounts of 22:6 n -3 (age 0+) and 18:2 n -6 fatty acids (age 1+) were noted. Simultaneously, the factory juveniles (age 0+ and 1+) differ from the wild juveniles in a lower ratio 18:3 n -3/18:2 n -6 of essential fatty acids (in 7.9 and 6.4-fold, respectively). The ratio of total polyunsaturated fatty acids of n -3/ n -6 families is reliably equal in the wild and the factory fingerlings (age 0+), whereas in parrs (age 1+) it is in 2-fold lower than for the factory fish. A relatively high content of oleic 18:1 n -9 fatty acid and minor 20:1 n -9, 22:1 n -11 fatty acids were found in the factory juveniles, but the level of saturated fatty acids was decreased due to 16:0 and 18:0. A high metabolic rate of fatty acid metabolism in the wild juveniles is evidenced by a higher ratio of 16:0/18:1 n -9 compared to that in the factory fish (1.50 and 1.47 vs 0.84 and 0.46 for fingerlings (age 0+) and parrs (age 1+), respectively. A lower metabolic rate of fatty acid metabolism in the factory juveniles, especially for parrs (age 1+), is accompanied by a high accumulation of their body mass (in 4-fold) compared with the wild individuals of the same age.