Effect of dietary linolenic and linoleic acids upon growth and lipid metabolism of rainbow trout (Salmo gairdneri)

Abstract

Nine diets, each containing different levels of linoleic acid (18:2 omega 6) and linolenic (18:3 omega 3) were fed to duplicate groups of rainbow trout for 14 weeks. The growth rate, feed efficiency, accumulated mortality, and fatty acid composition of neutral fat and phospholipids of these groups of fish were determined. The growth was slow in the groups of fish receiving diets containing (A) low concentration of 18:3 omega 3and (B) high concentration (5%) of 18:2 omega 6. The accumulated mortality was high in these groups of fish. The diet containing 1% of 18:3 omega 3 alone supported rapid fish growth with low mortality . The feed efficiency of this diet was also high. The metabolism of 18:2 omega 6 and 18:3 omega 3 in fish and their conversion to more unsaturated fatty acids typical of fish lipids was investigated.

Effects of temperature and dietary n-3 and n-6 fatty acids on endocytic processes in isolated rainbow trout (Oncorhynchus mykiss, Walbaum) hepatocytes

“…A lag phase before onset of degradation represents transport of the endocytosed marker to a degradative compartment within the cell. The fatty acid composition of the hepatocytes was affected by dietary fat in a similar manner to other cells and tissues from rainbow trout (Yu and Sinnhuber 1974;Castledine and Buckley 1982;Henderson and Sargent 1984;Boggio et al 1985;Sowizral et al 1990;Finstad and Thomassen 1991). The activation energy for the degradation of 125 I-TC-manBSA in trout hepatocytes between 2-20°C (164.2 kJ/mol) was found to be similar to what have been found for degradation of glycoproteins in rat hepatocytes between 20-40°C (125-140 kJ/mol) (Tolleshaug et al 1980).…”

Effects of dietary lipids on growth, fatty acid composition, intestinal absorption and hepatic storage in white sturgeon (Acipenser transmontanus R.) larvae

“…In freshwater fish, both the n -3 and n -6 series of PUFA are important for adequate nutrition, and 18 : 3 n -3 (linolenate) and 18 : 2 n -6 (linoleate) satisfy the essential fatty acid requirements for the n -3 and n -6 fatty acids, respectively (Bell et al 1986). The slower growth rates in the larvae may have resulted in part from the 2-3 times higher levels of 18 : 2 n -6 in the experimental diets than in the C17 diet because excess amounts of this dietary fatty acid have been shown to depress growth in rainbow trout (Yu and Sinnhuber, 1975). The relatively slow growth of larvae on the experimental diets may have resulted in part from the large amounts of the n -6 fatty acid in these diets.…”

Lipid metabolism and FA composition in tissues of Eurasian perch Perca fluviatilis as influenced by dietary fats

“…It is important therefore to develop alternatives to fish oil in fish feed formulations (25). During the past three decades, although many studies on n-3 and n-6 FA nutrition and metabolism have been conducted in both marine and freshwater fish (9,11,22,23,26,28,29,(31)(32)(33), limited information has been published on lipids, FA composition, and metabolism of percid fish (34-37). In fact, no study has yet addressed the influence of dietary fat source on lipid metabolism and FA composition of Eurasian perch Perca fluviatilis.…”