Muscle Fatty Acid Composition Research Articles

Changes in fatty acid composition in muscle of three farmed carp fish species (Labeo rohita, Cirrhinus mrigala, Catla catla) raised under the same conditions

This study was carried out to determine the proximate composition, fatty acid profile and biometric data for farm fish species Labeo rohita, Cirrhinus mrigala, Catla catla raised under identical conditions. The analysed fish species were found as source of high polyunsaturated fatty acids with low fat high protein. Fat content of the fish fillets was in range 2.57–3.11g/100g. Whereas fat content for feed was 14.90g/100g. The protein level for the three fish ranged from 20.00–23.57g/100g and in feed it was estimated in the range of 67.70g/100g. The palmitic acid and stearic acid were the main saturated fatty acids (SFA), oleic acid was the predominant MUFA while the docosahexanoic acid and eicopentanoic acid were the major PUFA. The percentage of DHA exceeded that of EPA in all fish species analysed. The n−3/n−6 ratio ranged from 1.69–1.91. PUFA/SFA ratio was much higher in L. rohita (1.40) due to abundance of n−3 PUFA, particularly DHA.

Low levels of dietary vitamin A increase intramuscular fat content and polyunsaturated fatty acid proportion in liver from lean pigs

The effect of the dietary vitamin A level and administration time on intramuscular fat (IMF) percentage and fatty acid composition of the subcutaneous outer layer, intramuscular and hepatic fat from lean pigs was investigated. One group received 13,000IU of vitamin A/kg diet for 11weeks (H); other group received 1300IU during the same period (L) and a third group received a vitamin A-enriched diet (13,000IU) for six weeks followed by a diet with 0IU of vitamin A for the last five weeks previous to slaughter (H-0). The dietary vitamin A level had no effect on growth performance and carcass traits. Pigs fed L showed higher IMF in Longissimus dorsi muscle when compared with group H. The L group also showed a higher saturated fatty acid (SFA) proportion and decreased MUFA/SFA ratio in the subcutaneous backfat outer layer. The dietary vitamin A level had no effect on the fatty acid composition of muscle. The suppression of vitamin A five weeks prior to slaughter did not affect IMF and fatty acid composition of the subcutaneous backfat outer layer, while in liver decreased SFA and increased PUFA.

Lipid and fatty acid compositions of cod (Gadus morhua), haddock (Melanogrammus aeglefinus) and halibut (Hippoglossus hippoglossus)

This study was conducted to compare lipid and fatty acid composition of cod, haddock and halibut. Three groups of cod (276 g ± 61 g), haddock (538 g ± 83 g) and halibut (3704 g ± 221 g) were maintained with commercial feeds mainly based on fish meal and marine fish oil for 12 weeks prior to sampling. The fatty acid compositions of muscle and liver were determined by GC/FID after derivatization of extracted lipids into fatty acid methyl esters (FAME). Lipids were also fractionated into neutral and polar lipids using Waters silica Sep-Pak?. The phospholipid fraction was further separated by high-performance thin-layer chromatography (HPTLC) and the FAME profile was obtained. Results of the present study showed that cod and haddock were lean fish and their total muscle lipid contents were 0.8% and 0.7%, respectively, with phospholipid constituting 83.6% and 87.5% of the total muscle lipid, respectively. Halibut was a medium-fat fish and its muscle lipid content was 8%, with 84% of the total muscle lipid being neutral lipid. Total liver lipid contents of cod, haddock and halibut were 36.9%, 67.2% and 30.7%, respectively, of which the neutral lipids accounted for the major fraction (88.1%–97.1%). Polyunsaturated fatty acids were the most abundant in cod and haddock muscle neutral lipid. Monounsaturated fatty acid level was the highest in halibut muscle neutral lipid. Fatty acid compositions of phospholipid were relatively constant. In summary, the liver of cod and haddock as lean fish was the main lipid reserve organ, and structural phospholipid is the major lipid form in flesh. However, as a medium-fat fish, halibut stored lipid in both their liver and muscle.

Effect of dietary fish oil replacement by rapeseed oil on the growth, fatty acid composition and serum non-specific immunity response of fingerling black carp, Mylopharyngodon piceus

An 8-week experiment on fingerling black carp Mylopharyngodon piceus was conducted to evaluate the effects of dietary fish oil (FO) supplement on growth, fatty acid composition and non-specific immunity responses. Five triplicate fingerling groups (initial weight = 2.72 ± 0.35 g) were fed isoenergetic and isonitrogenous diets in which the dietary FO was replaced with rapeseed oil (RO) in graded increments of 25% (0–100%). No significant effects were observed on specific growth rates, survival rates and feed conversion ratios, but there were significant differences in whole body moisture and liver lipid contents (P < 0.05), and the 100% RO replacement diet significantly enhanced hepatosomatic indexes compared to control group (P < 0.05). Other approximate whole body constituents, viscerasomatic ratios and condition factors were not influenced by dietary oil treatments. Fatty acid composition of muscle and liver was influenced by dietary fatty acid input, α-linoleic acid and γ-linolenic acid were significantly increased with increasing RO, but eicosapentaenoic acid, docosahexaenoic acid and the n-3/n-6 ratio were significantly reduced (P < 0.05). Alternative complement pathway, lysozyme and superoxide dismutase activities were not significantly influenced. These results indicate that black carp fed diets with FO supplement had similar growth and non-specific immunity to the fish fed diet with RO.

Dietary Inclusion of Tea Catechins Changes Fatty Acid Composition of Muscle in Goats

This study was conducted to examine dietary tea catechins (TC) supplementation on the fatty acid composition of muscle and ruminal bacteria in goats fed a maize stover-based diet. Forty goats, 8months old (16.2±1.2kg), were randomly divided into four equal groups (10 animals in each group) and assigned to four experiment diets with TC supplementation at four levels (0, 2,000, 3,000 and 4,000mg TC/kg feed, namely TC0, TC2000, TC3000 and TC4000, respectively). After a 60-day feeding period, all the goats were slaughtered and sampled. The results showed that dietary TC inclusion increased the average daily gain (ADG), protein content in the semimembranosus muscle and dry matter in the longissimus dorsi muscle (LD). Dietary TC supplementation increased the ratio of n-6 to n-3 fatty acid, the ratio of polyunsaturated fatty acids to saturated fatty acids was higher in TC3000 and TC4000 than in TC0 and TC2000 for LD. The current results implied that dietary inclusion of a suitable TC dose could improve the growth performance and increase the proportions of unsaturated fatty acids in muscle, and the biohydrogenation of ruminal microorganisms might change the profiles of fatty acids in the muscle of growing goats.

Variations in fatty acids composition in different tissues of the European eel (Anguilla anguilla L.) males during induced sexual maturation

Summary As no studies have been carried out to investigate the role of fatty acids in male European eel (Anguilla anguilla) maturation, the main aim of this work was to determine which fatty acids could play a central role in sexual maturation. To this end, European eel males were hormonally induced to sexual maturation and variations in fatty acid composition in muscle, liver, testis and milt were studied. Eels were injected weekly with hCG (Human Chorionic Gonadotropin) for 13 weeks and 10 eels per week were sacrificed. Histological analysis was performed to determine the spermatogenic stage of each male. In muscle, no variations or preferential utilization of fatty acids were detected. In liver, MUFAs (Monounsaturated Fatty Acids) were the most abundant fatty acids in the first weeks, while in the last week PUFAs (Polyunsaturated Fatty Acids) showed the highest concentrations. In testes, PUFAs content increased due to DHA (Docosahexaenoic acid), EPA (Eicosapentaenoic acid) and AA (Arachidonic acid) accumulation, while MUFAs diminished especially due to oleic and palmitoleic acid decrease. Linolenic (EPA and DHA precursor) and linoleic (AA precursor) acids also decreased. As evidenced by histology, main changes in testes matched the appearance of spermatids and first spermatozoa, at the end of meiotic divisions. In milt, no variations were appreciated and PUFAs were the most abundant fatty acids, close to 50%. Due to their increase in testes and the high concentration in milt, PUFAs probably play an important role in the sexual maturation of European eel. Further research is necessary to determine the relationship between feeding, fatty acids and sperm quality.

Effect of dietary n-3 HUFA on growth performance and tissue fatty acid composition of gibel carp Carassius auratus gibelio

A 12-week growth trial was conducted with gibel carp Carassius auratus gibelio (initial weight: 2.69 g) to evaluate the effects of dietary n-3 highly unsaturated fatty acids (n-3 HUFA) on growth performance and tissue fatty acid composition. Five diets of different n-3 HUFA levels from 0 to 17 g kg(-1) diet were supplemented at 80 g kg(-1) dietary lipid by including fish oil (FO) at 0, 25, 50, 75 and 100% of supplemental lipid. The remainder was coconut oil. The results showed that fish fed FO25 and FO50 obtained highest specific growth rate and lowest with FO0. Feed efficiency was highest at FO100 and lowest at FO0. Apparent digestibility coefficient of lipid increased with increasing dietary n-3 HUFA. The fish fed FO0 diet had the lowest thiobarbituric acid reactive substance in serum and muscle and highest moisture and lowest lipid content in viscera. Fatty acid compositions of muscle and liver were correlated with dietary fatty acids. Fish muscle concentration of 20:5n-3 increased with increasing dietary n-3 HUFA while the concentration of 22:6n-3 was distinctly reduced in FO0 group. It suggested that 4 g kg(-1) n-3 HUFA in diet could permit gibel carp normal growth performance and provide considerable n-3 HUFA in fish muscle. Excessive n-3 HUFA showed impact on growth performance of gibel carp.

Carcass characteristics, chemical and fatty acid composition of Longissimus muscle of Purunã bulls slaughtered at 18 or 24 months of age

This study was carried out to evaluate carcass characteristics, chemical and fatty acid composition of the Longissimus muscle of 78 Puruna bulls (39 bulls/treatment) slaughtered at 18 or 24 months old. The experimental design was completely randomized. The bulls were distributed into two systems: 1) Finished in feedlot 13 to 18 months old (T18), or 2) Finished in feedlot from 21 to 24 months old (T24). The diet, roughage:concentrate ratio of 52:48 (dry matter basis), contained 12% crude protein and 72% total digestible nutrients. The T18 system showed lower (p < 0.05) conformation (12.46 vs. 13.41 points), higher (p < 0.05) subcutaneous fat thickness (3.82 vs. 3.11 mm), lower (p < 0.05) Longissimus area (66.17 vs. 70.87 cm 2 ), lower (p < 0.05) muscle percentage (60.64 vs. 64.26%) and higher (p < 0.05) fat percentage (23.56 vs. 20.00%). Moisture (73.27%), ash (1.05%), crude protein percentages (22.56%) and total cholesterol content (36.47 mg/100 g of muscle) were similar (p < 0.05) between both slaughter ages. The total lipid percentage was higher (p < 0.05) for the T18 system (1.61 vs. 1.33%). Longissimus muscle fatty acid composition was not influenced (p < 0.05), with exception of C18:1 n-9 and C18:3 n-3, which were lower (p < 0.05) for the T18 system. Saturated fatty acids, monounsaturated fatty acids, polyunsaturated fatty acids, n-6, n-3 percentage and PUFA/SFA and n-6/n-3 ratio did not change (p < 0.05) according to slaughter age.

Effects of α-linolenic acid and eicosapentaenoic acid from linseed and algae, respectively, on reindeer (Rangifer tarandus tarandus L.) muscle fatty acid composition

In an earlier study, we concluded that pellet-fed reindeer could not elongate 18:3n − 3 (α-linolenic acid – ALA) sufficiently towards long-chain polyunsaturated fatty acids (LC PUFA) and need supplementation of LC PUFA. The present work investigated that the addition of n − 3 LC PUFA to feed in combination with ALA would increase the LC PUFA in the meat. Two groups of reindeer were fed pellets containing either linseed cake or linseed cake combined with algae (Nannochloropsis oculata) for 6 weeks before slaughter. Dietary n − 6/n − 3 ratio had a distinct influence on meat fatty acid (FA) composition when comparing linseed and linseed algae-fed animals with animals fed a conventional diet. Increased dietary proportions of ALA and eicosapentaenoic acid (EPA) increased these FA in muscle and docosapentaenoic acid (DPA) and docosahexaenoic acid in the polar lipid fraction compared to the conventional-fed animals. We concluded that an increased proportion of dietary EPA might lead to an increased elongation towards DPA in muscle. Algae and linseed are possible additives to reindeer feed in order to assure a similar valuable FA composition as in pasturing animals.

The effect of linseed diet on carcass value traits and fatty acid composition in muscle and fat tissue of fattening pigs

The aim of the study was to evaluate the effect of linseed in the diet of fattening pigs on carcass value traits and changes in the fatty acid profile in muscle and fat tissue. Thirty crossbred gilts were divided into two groups (control C and experimental L) and fed a commercial feed mixture for fattening pigs. Ground linseed was added to a feed mixture for the experimental group. The average daily gain, lean meat percentage and intramuscular fat content were not affected by the linseed diet but pH1 value and drip loss were significantly influenced by dietary treatment (P &amp;lt; 0.01). The inclusion of linseed increased linoleic and alpha-linolenic acid content in L group (P &amp;lt; 0.05, P &amp;lt; 0.01) while arachidonic acid content was decreased in both muscle (P &amp;gt; 0.05) and fat tissue (P &amp;lt; 0.01). The content of total n-6 PUFA and n-3 PUFA and their ratio were also determined. A significant decrease in the n-6/n-3PUFA ratio was found in L group compared to C group (P &amp;lt; 0.01). The total SFA content in muscle tissue was not significantly affected (P &amp;gt; 0.05) by the linseed diet but it was decreased (P &amp;lt; 0.01) in backfat. The MUFA/SFA ratio was not affected by the linseed diet (P &amp;gt; 0.05) whereas the SFA/PUFA ratio was reduced (P &amp;lt; 0.01).

Relationship between Lipid Peroxidation and Antioxidant Status in the Muscle of German Holstein Bulls Fed n-3 and n-6 PUFA-Enriched Diets

This study evaluated the influence of different n-3 and n-6 PUFA-enriched diets on the relationship between lipid peroxidation and antioxidant status by analyzing fatty acids (FA), lipid peroxidation, antioxidant capacity (AOC), antioxidant enzymes, trace elements, and fat-soluble vitamins in the longissimus muscle. Diet caused significant changes in muscle FA composition, leading to accumulation of beneficial n-3 FA. beta-Carotene and catalase activity were significantly elevated in muscle of the n-3 PUFA-enriched diet group compared to the n-6 PUFA-enriched diet group. Lipid peroxidation was higher in muscle of the n-3 PUFA-enriched diet group after 15 min of reaction time. There was no significant effect of diet on AOC, but it increased with reaction time. The present results suggest that the antioxidant defense in muscle of the n-3 PUFA-enriched diet group could balance reactive substances under low oxidative conditions. However, the antioxidant capacity was not sufficient under abundant accumulation of reactive substances.

Modelling the predictable effects of dietary lipid sources on the fillet fatty acid composition of one-year-old gilthead sea bream ( Sparus aurata L.)

The present study aimed to ascertain the different fatty acid (FA) descriptors linking dietary and muscle FA composition in one-year-old gilthead sea bream. For that purpose, our own published data along with additional data from the present study were compiled and analysed. High linear correlations ( r 2 = 0.90, P < 0.001) between dietary and muscle fatty acid composition were reported for monoenes, C18 polyunsaturated FA (PUFA) and long-chain PUFA (LC-PUFA). Prediction deviations due to changes in muscle fatness were analysed in an independent trial with two different feeding levels (full ration size, 30% restriction ration). Regardless of feeding regimen, predicted values for muscle FA at low concentrations deviated ( P < 0.001) from observed values, but good predictions with less than 6% deviations were found for abundant fatty acids (16:1 n−7, 18:1 n−9, 18:2 n−6, 18:3 n−3, 20:4 n−6, 20:5 n−3, 22:6 n−3). All this highlights the predictable effects of dietary oils in the muscle FA composition of gilthead sea bream, although further research is needed to cover all the range of commercial fish size and for the up-scaling of laboratory results to different fish farming conditions.

Fatty acid composition in adductor muscle of juvenile scallops ( Pecten maximus) from five Norwegian populations reared in the same environment

Adductor muscle fatty acid (FA) composition was compared in Pecten maximus juveniles originating from five locations along the Norwegian coast from 59°N to 65°N to detect possible population differences. Broodstock sized scallops were translocated to sea conditions by a scallop hatchery near Bergen (60°N) before spawning in February 2006. The scallop larvae and juveniles were reared in the same environment for two years and 10 individuals from each population were sampled in May 2007 and in May 2008 for analysis of the FAs in the adductor muscle. The total lipid content determined as total amount of FAs were 5.7 ± 0.3 mg per g tissue, and no significant difference was found among the five populations. The polyunsaturated FAs made up close to 60% of the total, with 20:5n3 and 22:6n3 dominating. The saturated FA content was approximately 30%, while the monounsaturated FA were less abundant (7–10%). The FA composition of the muscles of the five populations was similar within each year, with larger differences between the years. Multivariate, supervised learning method PLS, applied pairwise, showed distinct FA composition, between the scallops from the five locations, indicating population differences. The relatedness between the populations was different in the two years, but the distinct FA profiles of the adductor muscle could be used to distinguish between scallop populations on a local scale. The results indicate habitat-specific lipid metabolism which may have important implications for the scallop aquaculture industry in the context of producing well adapted individuals for the specific locations.

Effect of Groundnut Cake Substitution by Glandless Cottonseed Kernels on Broilers Production: Animal Performance, Nutrient Digestibility, Carcass Characteristics and Fatty Acid Composition of Muscle and Fat

Effect of Groundnut Cake Substitution by Glandless Cottonseed Kernels on Broilers Production: Animal Performance, Nutrient Digestibility, Carcass Characteristics and Fatty Acid Composition of Muscle and Fat

Soybean, palm kernel, and animal-vegetable oils and vitamin E supplementation effect on lipid oxidation stability of sous vide chicken meat

There is an increasing demand in precooked chicken meat products for restaurants and catering services. Because cooked chicken meat develops lipid oxidation relatively fast, sous vide chicken meat was studied to assess its shelf-life. Six hundred Cobb x Ross broilers were fed for 6 wk with a basal corn-soybean meal diet including soybean, palm kernel, or animal-vegetable oil, each supplemented with 33 or 200 mg/kg of dl-alpha-tocopheryl acetate. Broilers were randomly assigned into 6 treatments and 4 repetitions with 25 birds each. Boneless breast or thigh muscle pieces were dissected into 5 x 5 x 5 cm cubes, vacuum-packed, cooked in water bath (until 74 degrees C internal temperature), chilled, and stored at 4 degrees C for 1, 5, 10, 25, and 40 d. For each storage day, each pouch contained 3 pieces of meat, either breast or thigh. Thiobarbituric acid reactive substances analysis, to quantify malonaldehyde (MDA) values, was conducted to estimate the lipid oxidation development. Nonheme iron values of cooked meat were analyzed. Fatty acid methyl esters analysis was performed in chicken muscle to determine its fatty acid composition. There was no interaction between dietary fat and vitamin E level in all of the variables studied except in nonheme iron. Dietary fat significantly influenced the fatty acid composition of the muscle (P < 0.01), but it did not affect the MDA values, regardless of differences in the muscle fatty acid composition between treatments. Supplementation of the high level of vitamin E significantly reduced the MDA values in both breast and thigh meat (P < 0.01). The maximum MDA values were observed at d 40 of storage in thigh and breast meat in animal-vegetable and soybean oil treatments with the low levels of vitamin E, 0.91 and 0.70 mg/kg, respectively. Nonheme iron values in thigh meat differed between treatments at 1 or 25 d of storage but not in breast meat. In conclusion, refrigerated sous vide chicken meat has a prolonged shelf-life, which is enhanced by dietary supranutritional supplementation of vitamin E.

Comparative fatty acid profiles in edible parts of wild scallops from the Tunisian coast

Muscle and gonad fatty acid compositions from the Pectinids: Pecten jacobaeus, Chlamys varia and Flexopecten glaber, from the Tunisian coast, were analysed. The recorded main fatty acid components in both organs for the three species were C16:0, C18:0, C18:1, C20:5 ω3 and C22:6 ω3. Meanwhile, high proportions of EPA and DHA were recorded in the muscle of C. varia (10.1–20.4%), P. jacobaeus (7.68–14.9%), whereas the highest rates (8.98–7.78%) were recorded in gonad for F. glaber. Highest ω3/ ω6 ratios were recorded in muscle and gonad of C. varia (9.01 and 7.72, respectively). In P. jacobaeus, the muscle and the gonad had similar nutritional values. Muscle of C. varia had a better fatty acid composition than had the gonad, whilst the gonad value was higher than the muscle in the case of F. glaber.

Effects of different dietary lipid sources in the diet for Pangasius hypophthalmus (Sauvage, 1878) juvenile on growth performance, nutrient utilization, body indices and muscle and liver fatty acid composition

Four isonitrogenous (300 g kg−1 crude protein), isoenergetic (21 kJ g−1) experimental diets were formulated to contain fish oil (FO), soybean oil (SBO), crude palm oil (CPO) and linseed oil (LO), respectively, as lipid sources each at inclusion level of 120 g kg−1 and fed to triplicate groups of 15 juvenile iridescent shark, Pangasius hypophthalmus (Sauvage, 1878) (mean weight 10.00 ± 0.70 g) to apparent satiation twice daily for 12 weeks. The results showed that survival of fish was consistently over 95% for all treatments whereas growth performance in the SBO and CPO treatments was similar and significantly (P < 0.05) higher than for fish fed the LO diet. However, fish fed all vegetable oil-based diets performed better than those fed the FO diet. Muscle and liver fatty acid composition for all treatments generally reflected the composition in the diet and the ratio of n-3/n-6 was found to play an important role in P. hypophthalmus, suggesting that excessive amounts of n-3 fatty acids reduce the overall growth performance. Results of this study thus suggests that P. hypophthalmus fed diets containing vegetable oils (especially CPO and SBO) produce better growth than those fed FO diet without showing any signs of nutrient deficiency.

Tissue-specific robustness of fatty acid signatures in cultured gilthead sea bream (Sparus aurata L.) fed practical diets with a combined high replacement of fish meal and fish oil1

The present study aimed to determine the tissue-specific robustness of fatty acid (FA) signatures of gilthead sea bream (Sparus aurata L.) by analyzing the changes in lipid class and FA composition of skeletal muscle, brain, liver, and mesenteric adipose tissue. Triplicate groups of fish were fed to visual satiety over a 14-mo production cycle with 2 practical plant protein-based diets formulated with either fish oil or a blend of vegetable oils (66% of fish oil replacement) to contain 53% CP and 21% crude fat on a DM basis. Growth rates (P = 0.22) and tissue lipid class composition were not altered by the dietary treatment (P = 0.34 and 0.52 for neutral lipids and phospholipids, respectively). The FA signatures of neutral lipids reflected the composition of the diet, although the output of principal components analysis revealed a divergent FA profile for liver compared with skeletal muscle, brain, and mesenteric adipose tissue. Because the theoretical EFA needs were met by the 2 diets, the FA composition of phospholipids remained almost unaltered in all tissues. Interestingly, however, the brain showed the greatest robustness and regulatory capacity to preserve the phenotype of fish fed fish oil-based diets. The FA signatures of total lipids are a combinatory result of neutral and polar lipids, and the most relevant fat storage tissues (mesenteric adipose tissue and skeletal muscle) were more easily influenced by dietary FA composition. The present study provides new insights into fish tissue FA composition and reinforces the use of FA signatures as useful criteria in determining whether EFA requirements for a wide range of physiological processes, including those of neural tissues, can be met with practical fish feeds.

Fish oil in feeds for entire male and female pigs: Changes in muscle fatty acid composition and stability of sensory quality

A total of 72 crossbred [(Norwegian Landrace x Yorkshire) x Duroc] male and female growing-finishing pigs were restrictedly fed diets containing fish oil to study the fatty acid composition of Musculus longissimusdorsi and sensory quality of belly and neck. Six diets were used: two low-fat diets with or without 0.5% fish oil added, and four medium-fat diets with palm kernel oil to fish oil in ratios given as % inclusion: 4.1:0.0, 3.9:0.3, 3.6:0.5 and 3.4:0.7. Feeding fish oil gave a dose-dependent response between fatty acids in the diets and in the M.longissimusdorsi and increased the level of very long chain n-3 fatty acids, especially the C22:5n-3 (DPA). A more efficient n-3 fatty acids deposition was obtained when given as a medium-fat diet rather than the low-fat diet. Female pigs had a significant higher percentage of monounsaturated fatty acids and C18:1 than males suggesting a gender related difference in the delta-9-desaturase activity. No significant differences were found in sensory attributes for short-term stored neck and belly. For pigs fed the highest level of fish oil (0.7%) long-term stored (12 months at -80 degrees C, 6 months at -20 degrees C) belly showed a slight increase in fish oil flavour. After warmed-over treatment, fish oil odour and flavour as well as rancid flavour were increased in this group. The results suggest levels of dietary fish oil up to 0.5% produce a healthier meat fatty acid composition, without negative effects on sensory attributes, even in long-termed stored belly.

Effects of Dietary L-carnitine Supplementation on Growth, Muscle Fatty acid Composition and Economic Profit of Rainbow Trout (Oncorhynchus mykiss)

In this study, the effect of dietary L-carnitine on growth, proximate and muscle fatty acid compositions of rainbow trout (Oncorhynchus mykiss) were investigated. The fish were fed with diets containing 300 mg kg -1 L-carnitine (LC300), other group was fed with diets containing 600 mg kg -1 L-carnitine (LC600) and control group was not supplementary L-carnitine for 63 days. The weight gain of LC600 fed with L-carnitine supplemented was found to be 7.73% higher than in control group. Feed conversion ratio in LC600 (1.66) and LC300 (1.60) is better than in control group (2.00). L-carnitine supplemented groups would be lower cost of production than control. Economic conversion ratio (ECR) of LC300 (2.71 US.$ kg -1 ) would represent a saving of 0.44 US.$ kg -1 compared to the control. L-carnitine administration did not affect proximate composition of muscle except for protein percent. Protein content of L-carnitine supplemented groups was higher than control group. Total saturated monounsaturated and polyunsaturated muscle fatty acid content increased by L-carnitine supplementation in rainbow trout. The results indicate that supplementation of 600 mg L-carnitine/kg diet is more effective on growth than the other L-carnitine supplementation level 300 mg kg -1 and control diet in commercial cage conditions.