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Tissue Fatty Acid Composition (tissue + fatty_acid_composition)

Distribution by Scientific Domains

Earth and Environmental Science	100%

Selected Abstracts

Effects of dietary vitamin E supplementation on growth performance, lipid peroxidation and tissue fatty acid composition of black sea bream (Acanthopagrus schlegeli) fed oxidized fish oil

AQUACULTURE NUTRITION, Issue 3 2009
S. PENG
Abstract A 9-week feeding experiment was conducted to evaluate the effects of dietary vitamin E supplementation on growth, lipid peroxidation and fatty acid composition of black sea bream fed oxidized oil. The FL and OL diets contained fresh fish oil and oxidized oil, respectively, without additional vitamin E supplementation. Another four ,-tocopherol levels (150, 250, 450 and 800 mg kg,1 diet) were used within the OL diet, giving a total of six experimental diets. Fish were hand-fed to apparent satiation twice daily. At end of the trial, the weight gain and survival rate of fish were significantly reduced by diets with oxidized oil, whereas hepatosomatic index was remarkably high in fish fed oxidized oil diet. However, vitamin E supplementation to diet significantly improved growth performance and increased vitamin E content in the liver. Although, liver thiobarbituric acid reactive substances and docosahexaenoic acid were significantly increased by dietary oxidized oil, their levels were reduced by dietary vitamin E supplementation. Our results indicate that the fish were performing the best at intermediate concentrations of ,-tocopherol and a dose of >150 mg ,-tocopherol kg,1 diet could reduce lipid peroxidation and improve fish growth performance when oxidized oils exist in diet. [source]

Effects of dietary protein, and fat level and rapeseed oil on growth and tissue fatty acid composition and metabolism in Atlantic salmon (Salmo salar L.) reared at low water temperatures

AQUACULTURE NUTRITION, Issue 4 2007
V. KARALAZOS
Abstract A 12-week feeding trial was conducted to elucidate the interactive effects of dietary fat, protein contents and oil source on growth, whole body proximate composition, protein productive value (PPV) and fatty acid (FA) composition of muscle and liver in Atlantic salmon (Salmo salar L.)` at low water temperatures (4.2 °C). Triplicate groups of Atlantic salmon (initial weight 1168 g) were fed six isoenergetic diets, formulated to provide either 390 g kg,1 protein and 320 g kg,1 fat (high-protein diets) or 340 g kg,1 protein and 360 g kg,1 fat (low-protein diets). Within each dietary protein/fat level, crude rapeseed oil (RO) comprised 0, 30 or 60% (R0, R30, R60, respectively) of the added oil. After 12 weeks, the overall growth and feed conversion ratio (FCR) were very good for all treatments [thermal growth coefficient (TGC): 4.76 (±0.23); FCR: 0.85 (±0.02)]. Significant effects were shown owing to the oil source on specific growth rate and TGC only. The liver and muscle FA compositions were highly affected by the graded inclusion of RO. The PPV was significantly affected by the dietary protein level. The results of this study suggest that more sustainable, lower protein diets with moderate RO inclusion can be used in Atlantic salmon culture at low water temperatures with no negative effects on growth and feed conversion, no major detrimental effects on lipid and FA metabolism and a positive effect on protein sparing. [source]

Evaluation of canola oils as alternative lipid resources in diets for juvenile red seabream, Pagrus auratus

AQUACULTURE NUTRITION, Issue 5 2003
B. Glencross
Abstract This study examined three potential oil resources, crude and refined canola oil and refined soybean oil as replacements for added dietary fish oil in diets for juvenile red seabream. These oil resources were evaluated for their potential to replace added fish oil (40 g kg,1) in fishmeal based (600 g kg,1) diets, with 100 g kg,1 of total lipids. Each of the three plant oils was used to replace 25%, 50%, 75% or 100% of the added dietary fish oil. Each of the three plant oils showed potential as a replacement for dietary fish oil, although a significant reduction in growth and feed utilisation was observed with the complete (100%) replacement of added fish oil by crude canola oil. No other significant effects of oil type or inclusion level on growth were apparent. A negative control (no added fish oil or plant oil, 60 g kg,1 of total lipid) yielded poorer growth than all treatments except the diet containing 40 g kg,1 of added crude canola oil (100% replacement). This observation confirmed that the added oils were utilized by the fish. A positive control diet containing 80 g kg,1 of added fish oil (140 g kg,1 total dietary lipid) sustained the best growth in the study, confirming that the 13 experimental diets were energy limiting as planned. Notably, few effects of the alternative oils were seen on the proximate composition of the fish. However, the influence of the alternative oils on the tissue fatty acid composition was considerable, irrespective of plant oil type or processing grade. Particularly notable was the overall increase in the level of polyunsaturated fatty acids in the tissues of the fish fed the plant oil diets, with these trends becoming more apparent with the greater levels of fish oil replacement. Minimal reductions in the levels of the long-chain polyunsaturated fatty acids of eicosapentaenoic (20:5n-3) and docosahexaenoic (22:6n-3) acid were observed from any of the plant oil treatments. Sensory assessment, by an Australian taste panel, of the fish fed the fish oil reference, or the 100% replacement by refined canola or refined soybean diets showed a preference in order of canola oil > soybean oil > fish oil fed fish. Clearly, both canola and soybean oils have considerable potential as replacements of fish oils in diets for this species. [source]

Effects of dietary lipid level on liver and muscle lipid deposition in juvenile haddock, Melanogrammus aeglefinus L.

AQUACULTURE RESEARCH, Issue 2001
D A Nanton
Abstract The effects of dietary lipid levels on growth, feed utilization, hepatosomatic index (HSI), liver lipid deposition and tissue fatty acid composition in haddock were investigated. Triplicate tanks of juvenile haddock (6.9 g) were fed graded levels of herring oil to supply 14, 16, 19 and 22% lipid (DM, dry matter) in fish meal-based, isonitrogenous diets. Growth and feed conversion ratio of juvenile haddock was not significantly (P < 0.05) affected by increasing the lipid content of the diet. A significant increase in HSI (9.8,12.1%), total liver lipid (63.2,69.0%) and whole body gross energy content (6.03,6.39 kcal g,1 DM) were observed in haddock fed 14% vs. 22% lipid. Although the HSI of these cultured haddock was high in comparison to wild gadoids, histological analyses of these haddock livers did not reveal any overt pathology. Muscle lipid levels (1.0%) did not increase significantly with dietary lipid. Liver fatty acid levels mirrored dietary fatty acid (FA) composition. The muscle consisted mainly of polar lipid (84.3 ± 2.5% of total lipid) and a large proportion (52.6 ± 0.8%) of polyunsaturated FA. A dietary lipid level of 14% DM or less is recommended for juvenile haddock. [source]

Influence of dietary palm oil on growth, tissue fatty acid compositions, and fatty acid metabolism in liver and intestine in rainbow trout (Oncorhynchus mykiss)

AQUACULTURE NUTRITION, Issue 4 2005
J. FONSECA-MADRIGAL
Abstract This study aimed to investigate the effects of dietary crude palm oil (CPO) on fatty acid metabolism in liver and intestine of rainbow trout. Triplicate groups of rainbow trout for 10 weeks at 13 °C were fed on diets in which CPO replaced fish oil (FO) in a graded manner (0,100%). At the end of the trial, fatty acid compositions of flesh, liver and pyloric caeca were determined and highly unsaturated fatty acid (HUFA) synthesis and fatty acid oxidation were estimated in isolated hepatocytes and caecal enterocytes using [1- 14C]18:3n-3 as substrate. Growth performance and feed efficiency were unaffected by dietary CPO. Fatty acid compositions of selected tissues reflected the dietary fatty acid composition with increasing CPO resulting in increased proportions of 18:1n-9 and 18:2n-6 and decreased proportions of n-3HUFA, 20:5n-3 and 22:6n-3. Palmitic acid, 16:0, was also increased in flesh and pyloric caeca, but not in liver. The capacity of HUFA synthesis from 18:3n-3 increased by up to threefold in both hepatocytes and enterocytes in response to graded increases in dietary CPO. In contrast, oxidation of 18:3n-3 was unaffected by dietary CPO in hepatocytes and reduced by high levels of dietary CPO in enterocytes. The results of this study suggest that CPO can be used at least to partially replace FO in diets for rainbow trout in terms of permitting similar growth and feed conversion, and having no major detrimental effects on lipid and fatty acid metabolism, although flesh fatty acid compositions are significantly affected at an inclusion level above 50%, with n-3HUFA reduced by up to 40%. [source]