Dietary Lipid Sources Research Articles

Lipidomics profiling of goat milk, soymilk and bovine milk by UPLC-Q-Exactive Orbitrap Mass Spectrometry.

Lipids are very important for human health and milk is a rich dietary source of lipids. In this study, the lipid content in three types of milk (goat, soy and bovine) were determined by using UPLC-Q-Exactive Orbitrap Mass Spectrometry. A total of 13 classes of lipids (including Cer, SM, LPC, PC, PE, DG, TG, PA, PG, PI, PS, LPE, FA) were measured. Moreover, lipid profiles differed significantly between the different milk types. Soymilk is rich in phospholipids including PC, PE, PS, PG, while goat milk is rich in medium chain triglycerides (MCT), USFA, ω-6 FA and ω-3 FA, especially EPA and DHA. Furthermore, a PLS model was established for differentiation of milk types based on the lipid profiles. A total of 14 lipids were identified as biomarkers for differentiation of milk types, thus providing a basis for milk authentication and detection of adulteration.

Changes in fatty acid profile and chemical composition of meagre (Argyrosomus regius) fed with different lipid and selenium levels

This study aimed to evaluate changes in body composition, specially muscle and liver fatty acid profile in meagre (Argyrosomus regius) fed with different dietary lipid sources and levels, with or without selenium supplementation. Six hundred meagre were fed twice a day, 6 days per week, with eight experimental diets for 60 days. Diets were a combination of fish oil or a vegetable blend (45% linseed + 35% rapeseed + 20% soybean oil), at 12 or 17% of oil and 0 or 1 mg/kg of organic selenium, in a 2 × 2 × 2 factorial design. The whole body protein and lipid content were affected by the dietary oil source. Fish oil diets increased long‐chain (LC) PUFAs content in the edible tissues, while vegetable oil‐based diets increased short‐chain (SC) PUFAs. Vegetable oil diet tended to decrease the fish protein content. A higher lipid liver content was observed in meagre fed the vegetable oil blend. The results also suggested the ability of meagre to convert SC‐PUFA to LC‐PUFA when the vegetable oil is included in their diet. The possibility for partial substitution of fish oil by vegetable oil in meagre diets, resulting in lower dependence of fish oil in meagre farming, is also demonstrated here.Practical applications: The growing importance of aquaculture for basic food supply, and the urge for cost‐effective and sustainable feeds that maintain or even increase fish quality, makes the search for alternatives to common feeds a route of upmost importance, as the vegetable oil here addressed. SC‐PUFA and LC‐PUFA contents of the studied tissues increased with diets supplemented with 17% oil level, which may ultimately add more value to this farmed species. These results indicate the possibility of the partial substitution of fish oil by vegetable oil in meagre diets, resulting in lower dependence on fish oil for fish farming.Meagre were fed with different dietary lipid sources and levels, with or without selenium supplementation, in a total of eight experimental diets during 60 days, in a 2 × 2 × 2 factorial design. Fish oil diet increases HUFAs and vegetable oil diet increases PUFAs in body composition. There is great potential for partial substitution of fish oil by vegetable oil in meagre (Argyrosomus regius) diets, resulting in lower dependence of fish oil in meagre farming.

Dietary fat preference and effects on performance of piglets at weaning.

ObjectiveAn experiment was to evaluate the interplay of dietary lipid sources and feeding regime in the transition from sow milk to solid food of abruptly weaned piglets.MethodsSoon after weaning, 144 piglets were selected and were trained over a 15 day period to experience gradually reducing dietary fat content from 12% to 6% for lard (L), soybean oil (S), and coconut oil (C) and their feeding behavior and diet preference then tested in a behavior observation experiment. Another 324 weaned piglets were used in three consecutive feeding experiments to measure the effect of different dietary fats on performance and feed choice in the four weeks after abrupt weaning. The lipid sources were used as supplements in a 3% crude fat corn/soya basal diet, with 6% of each being included to form diets 9C, 9S, and 9L respectively, and their effects on performance measured. Combinations of these diets were then further compared in fixed blends or free choice selection experiments.ResultsPiglets pre-trained to experience reducing lipid inclusion showed different subsequent preferences according to lipid source, with a preference for lard at 9%, soybean oil at 3%, and coconut oil at 6% inclusion rate (p<0.001). Following abrupt weaning, whilst after 4 weeks those fed 9C had the heaviest body weights (18.13 kg, p = 0.006). Piglets fed a fixed 1:1 blend of 9C+9S had a poorer feed conversion ratio (FCR = 1.80) than those fed a blend of 9C+9L (FCR = 1.4). The 9C and 9L combination groups showed better performance in both fixed blend and free choice feeding regimes.ConclusionAfter abrupt weaning, they still have dependence on high oleic acid lipids as found in sow milk. A feeding regime offering free choice combination of lipids might give the possibility for piglets to cope better with the transition at weaning, but further research is needed.

Molecular cloning and characterization of unfolded protein response genes from large yellow croaker (Larimichthys crocea) and their expression in response to dietary fatty acids.

The unfolded protein response (UPR) is a mechanism to cope with perturbed endoplasmic reticulum (ER) functions or accumulation of unfolded protein in the ER in eukaryotic cells. Furthermore, the UPR also participates in a number of physiological and pathological processes, such as nutrient sensing, lipid synthesis, and inflammatory response. In this study, four UPR-related genes (GRP78/BiP, ATF6α, XBP1 and CHO) were isolated characterized from large yellow croaker (Larimichthys crocea), and their expression in response to dietary lipid sources (various fatty acids) such as fish oil (FO), palmic acid (PA), olive oil (OO), sunflower oil (SO), and perilla oil (PO), were examined following feeding. The results showed that the four UPR-related proteins contained highly conserved functional domains and had the closest phylogenetic relationships with other fishes. Additionally, these genes were ubiquitously expressed in large yellow croaker, as in zebrafish and medaka. Moreover, GRP78, ATF6α and spliced XBP1 (XBP1s) mRNA levels in the liver, not in adipose tissue, were significantly increased in the SO group compared to the other groups (P<0.05). These results indicated that dietary SO activated UPR, and the activation of UPR might provide a mechanism to improve ER function, but probably stimulated lipid synthesis and caused inflammatory response in the liver of large yellow croaker.

The implications of substituting dietary fish oil with vegetable oils on the growth performance, fillet fatty acid profile and modulation of the fatty acid elongase, desaturase and oxidation activities of red hybrid tilapia, Oreochromis sp.

A 75-day feeding trial was carried out to examine the effects of fish oil (FO) replacement with various alternative vegetable oil (VO) on the growth performance and feed utilization efficiency of red hybrid tilapia (Oreochromis sp.). The VO evaluated included canola oil (high in monoenes), perilla oil (high in n−3 polyunsaturated fatty acids, PUFA), sunflower oil (high in n−6 PUFA) and refined, bleached, deodorized palm olein (high in saturates) added as the sole lipid source in semi-purified experimental diets. The ability of hybrid tilapia to biosynthesize long chain-polyunsaturated fatty acids (LC-PUFA) from dietary 18:2n−6 and 18:3n−3 was also determined. With the exception of sunflower oil, results showed that total FO replacement by various VO did not compromise (P>0.05) tilapia growth performance. However, dietary VO significantly (P<0.05) influenced the fatty acid composition of tilapia fillet and whole-body lipids through changes in the overall fatty acid metabolism. The total Δ5 and Δ6 fatty acid desaturase activities were exclusively triggered in tilapia fed VO-based diets. Tilapia fed the VO diets, which contained no PUFA longer than C18, recorded significant amounts of both n−6 and n−3 LC-PUFA in their tissue lipids. Dietary canola oil (CO) increased Δ-6 desaturation of 18:3n−3 to the greatest extent despite the dietary 18:3n−3 content being comparatively lower than dietary perilla oil (PeO). Beta-oxidation of 18:3n−3 was observed to be highest in fish fed the PeO diet, indicating that the 18:3n−3 content in the PeO diet exceeded the optimum substrate level for Δ-6 desaturase. Omega-3 LC-PUFA biosynthetic activities were highest in fish fed the CO diet and resulted in a comparatively higher eicosapentaenoic acid (EPA)+docosahexaenoic acid (DHA) content than in fish fed other VO diets. However, endogenous LC-PUFA synthesis induced by the VO diets was insufficient to rival the n−3 LC-PUFA content of fish fed the FO diet. It was also observed that β-oxidation of 18:3n−3 and 18:2n−6 was regulated by tissue n−3/n−6 PUFA ratio and proportional to their dietary level. This study provided the first comprehensive evidence of the significant impact of dietary oils with different fatty acid class profile on the in vivo fatty acid metabolism of tilapia. Statement of relevanceMarine fish oil (FO) was traditionally used as the major lipid source in commercial tilapia feeds to provide energy and essential fatty acids as well as to impart palability to the feed. With the rising costs of FO and limited global supplies, the use of alternative lipid resources in aquafeeds, including tilapia feeds, has become more critical to enable the continued sustainability and scalability of the global aquaculture industry. Terrestrial vegetable oil (VO) are viable alternatives since their production is more sustainable and cost-effective. However, unlike FO, which is rich in n−3 long chain-polyunsaturated fatty acids (LC-PUFA), VO are deficient in these essential fatty acids and but high in other fatty acid classes. The present study evaluated perilla oil (high levels of n−3 polyunsaturated fatty acids), sunflower oil (rich in n−6 PUFA), canola oil (high amounts of monounsaturated fatty acids) and palm oil (rich in saturated fatty acids) together with fish oil. By understanding how dietary lipid source with different major fatty acid classes modulates in vivo fatty acid metabolism, we can better formulate fish feeds that can optimize not only growth performance but also maintaining the health benefits of eating seafood for the human consumer in regards to eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels in farmed fish fillets. As far as we know, there is currently no information comparing the fatty acid metabolism of red hybrid tilapia fed diets with lipids containing different major fatty acid classes.

Effects of Vitamin E with Different Levels or Sources of Dietary Lipid on the Growth and Expression of Inflammatory, Oxidative Stress, and Apoptotic Genes in the Head Kidney of Olive Flounder, Paralichthys olivaceus

AbstractThis study has assessed the effects of vitamin E (−E, +LE, +HE; 0, 100, 1000 mg/kg, respectively) in fish diets containing high levels (HL; 10%) of fish oil (FO) or mixed vegetable oils (VO) on the growth and inflammatory, oxidative stress, and apoptotic gene expression in the head kidney of olive flounder, Paralichthys olivaceus. Consequently, the highest weight gain was achieved in the FO group and the lowest in the HL‐VO + LE group. The gene expression levels of each group were compared to the 5% FO group. The 5% VO group showed higher expression levels of tumor necrosis factor (TNF) α, interleukin (IL)‐1β, and scinderin‐like (ScinL) genes. Although lysozyme gene expression was higher in the HL‐VO + LE group, the other gene expression levels of the HL‐FO/VO + LE groups were not different from those of the FO group. The HL‐FO/VO−E/+HE groups showed a higher TNFα gene expression, but the cytochrome oxidase subunit III gene expression was higher in the HL‐FO−E and HL‐VO + HE groups. Lysozyme gene expression was higher in the HL‐FO−E and HL‐VO−E/+HE groups. IL‐6 and ScinL gene expression were higher in the HL‐VO‐E and HL‐VO + HE groups, respectively. In conclusion, mixed VO and too high or too low vitamin E levels in fish diets may affect inflammatory, oxidative stress, and apoptotic gene expression in the head kidney of olive flounder.

Different Dietary Lipid Sources Affect Plasma Lipid Composition but Not Stress Tolerance or Growth of Hybrid Striped Bass

AbstractTo determine whether dietary lipid sources used in regimens to replace fish oil differentially impact the production performance and physiological status of hybrid Striped Bass (White Bass Morone chrysops × Striped Bass M. saxatilis), the growth performance and stress response of fish raised on diets containing oil from fish, canola, corn, or flaxseed were evaluated. Production performance was unaffected by diet. Net‐chasing and handling stress challenges elicited changes in hematology consistent with the generalized stress response, and there was a significant main effect of stressor exposure (P &lt; 0.01) on both plasma cortisol and osmolality, as well as a main effect of lipid source (P &lt; 0.05) on plasma osmolality. Across diets, cortisol and osmolality levels were highest 1 h after stressor exposure (411 ng/mL and 385 mOsm/kg, respectively) but decreased significantly by 4 h poststressor (169 ng/mL and 332 mOsm/kg, respectively). The plasma lipid fatty acid (FA) profile was influenced by diet and generally reflected the FA profile in the feed. However, higher levels of saturated and monounsaturated FAs and lower levels of polyunsaturated FAs were typically observed shortly after stressor exposure. Although differences in hematology were associated with differences in lipid source and stressor exposure, neither obvious impairment of physiological function nor gross effects (i.e., morbidity and mortality) were observed.

&lt;b&gt;Lipid sources in diets for egg-laying japanese quail: performance and egg quality

This study evaluated the effect of using lipid sources of plant and animal origin in diets for Japanese quail (Coturnix coturnix japonica) on production performance and internal egg quality. Japanese quails (n = 160) were distributed in a completely randomized design with four treatments and eight replications of five birds each. Lipid sources evaluated were: soybean oil, from poultry slaughterhouse, fish waste and grape seed. The characteristics of performance and internal egg quality were measured every 21 days for a total period of 84 days. Data were subjected to analysis of variance and the means were compared by Tukey’s test. There was no effect of treatments on the production performance of birds, except for feed intake, which was higher for birds fed grape seed oil in the diet. Lipid sources evaluated had no influence on the internal egg quality. It can be concluded that the lipid sources evaluated here in can be used as alternative energy in feed for laying quails, without affecting the performance and internal egg quality.

Liver and intestine oxidative status of gilthead sea bream fed vegetable oil and carbohydrate rich diets

This study investigated the effects of dietary lipid source and carbohydrate content on liver and intestine oxidative status of gilthead sea bream juveniles, by assessing antioxidant defences enzymes (superoxide dismutase, SOD; catalase, CAT; glutathione peroxidase, GPX; glutathione reductase, GR; and glucose-6-phosphate dehydrogenase, G6PD); total, reduced, and oxidized glutathione (GSH); and lipid peroxidation (LPO). Fish were fed for 13weeks with four diets (2×2 factorial design) differing in lipid source (Fish oil- FO or a blend of vegetable oil-VO) and carbohydrate level (0 or 20% of digestible starch). Dietary VO reduced liver and intestine LPO, and enhanced liver GSH redox status (total and reduced GSH), GPX, GR, and G6PD activities, while in the intestine a decrease of G6PD activity and an increase of catalase activity and of reduced GSH (only in the carbohydrate diet) were recorded. Dietary carbohydrate promoted an increase of hepatic SOD and G6PD activities, and a decrease of CAT activity, total, oxidized, and reduced GSH, LPO, and oxidative stress index (OSI) (only in the FO diet). In the intestine, dietary carbohydrate did not induce alterations in LPO or enzymatic antioxidant defences but negatively affected GSH redox status (OSI, reduced and oxidized GSH). Overall, few interactions between dietary lipid source and carbohydrates were recorded. Dietary VO appeared to have a protective role against LPO in both tissues. Dissimilarities in liver and intestine susceptibility to LPO by dietary carbohydrate may reflect differences in glucose and GSH metabolism in the two tissues. Statement of relevancePlant related macronutrients improve fish oxidative status.

Lipidomic investigation of eggs' yolk: Changes in lipid profile of eggs from different conditions

Eggs are one of the main foods eaten worldwide. Nutritionally they are one of the main sources of dietary lipids, impacting human health. Egg yolk lipid composition changes depending on different conditions associated with hens raising. Therefore, the purpose of our work was to use a lipidomic approach as a tool to evaluate if different diets (vegetable versus animal) and raising environments (free range versus indoor) interfere in the triacylglycerol (TAG) and phospholipid (PL) profiles of eggs' yolks and to use such differences to differentiate eggs according to their origin. To achieve that goal, total lipid extracts were obtained and then fractionated by solid-phase chromatography. TAGs fraction was analysed by ESI-MS and PLs fraction by HILIC-LC-MS/MS. TAG and five PL classes were identified, namely PC, LPC, PE, LPE and SM. Fatty acids (FA) esterified to the glycerol backbone of PL ranged between C16:0 and C22:6. On the other hand, FA esterified to TAG ranged from C14:0 to C20:0. Major differences on the PL profile were observed regarding eggs from free-range hens and fed with vegetable origin food and eggs from the remaining conditions, once the former presented higher levels of PC (O-34:0), PC (34:1) and PE (34:1). Eggs from hens fed with animal origin food contained PL and TAG molecular species richer in n-6 FA, according to GC–MS and to LC-MS/MS data. The lipidomic approach used herein proved to be promising in differentiating eggs from hens with different raising conditions.

An experimental analysis of the effects of dietary lipid sources and feeding ration on the reproductive performance, egg and larval quality of Nile tilapia, Oreochromis niloticus (L.)

An experimental analysis of the effects of dietary lipid sources and feeding ration on the reproductive performance, egg and larval quality of Nile tilapia, Oreochromis niloticus (L.)

사료 지질원이 비단잉어(Cyprinus carpio var. koi) 치어의 성장 및 체조성에 미치는 영향

사료 지질원이 비단잉어(Cyprinus carpio var. koi) 치어의 성장 및 체조성에 미치는 영향

Evaluation of Dietary Lipid Sources for the Juvenile Lost River Sucker

AbstractThe establishment of a propagation program is among the recommended actions of the U.S. Fish and Wildlife Service recovery plan for the endangered Lost River Sucker Deltistes luxatus. As an initial step in diet development, a feeding trial was conducted to identify appropriate dietary lipid sources to feed juvenile Lost River Suckers at a rate of 0.47 g/fish. Six dietary treatments were produced by adding the following to a basal diet: (1) marine fish oil (Fish) as a control, (2) flaxseed oil (Flax), (3) soybean oil (Soy), or a 1:1 mixture of (4) fish and flax oil (Fish/Flax), (5) fish and soy oil (Fish/Soy), or (6) flax and soy oil (Flax/Soy). At the conclusion of the feeding trial weight gain of fish fed the control diet (Fish) was not significantly different than that of fish fed the other dietary treatments. However, weight gain of fish fed Soy was significantly higher than that of fish fed Fish/Flax. Whole‐body lipid was significantly higher in fish fed Soy than in fish fed Fish, Flax, Fish/Flax, or Fish/Soy, but not significantly different than that in fish fed Flax/Soy. Generally, whole body fatty acid profiles reflected the fatty acid profiles of their respective dietary treatments. These results suggest soybean oil is an appropriate dietary lipid source for the Lost River Sucker, but more research on quantitative dietary requirements is needed for successful propagation of this species.

Regulation of glucose and lipid metabolism by dietary carbohydrate levels and lipid sources in gilthead sea bream juveniles.

The long-term effects on growth performance, body composition, plasma metabolites, liver and intestine glucose and lipid metabolism were assessed in gilthead sea bream juveniles fed diets without carbohydrates (CH-) or carbohydrate-enriched (20 % gelatinised starch, CH+) combined with two lipid sources (fish oil; or vegetable oil (VO)). No differences in growth performance among treatments were observed. Carbohydrate intake was associated with increased hepatic transcripts of glucokinase but not of 6-phosphofructokinase. Expression of phosphoenolpyruvate carboxykinase was down-regulated by carbohydrate intake, whereas, unexpectedly, glucose 6-phosphatase was up-regulated. Lipogenic enzyme activities (glucose-6-phosphate dehydrogenase, malic enzyme, fatty acid synthase) and ∆6 fatty acyl desaturase (FADS2) transcripts were increased in liver of fish fed CH+ diets, supporting an enhanced potential for lipogenesis and long-chain PUFA (LC-PUFA) biosynthesis. Despite the lower hepatic cholesterol content in CH+ groups, no influence on the expression of genes related to cholesterol efflux (ATP-binding cassette G5) and biosynthesis (lanosterol 14 α-demethylase, cytochrome P450 51 cytochrome P450 51 (CYP51A1); 7-dehydrocholesterol reductase) was recorded at the hepatic level. At the intestinal level, however, induction of CYP51A1 transcripts by carbohydrate intake was recorded. Dietary VO led to decreased plasma phospholipid and cholesterol concentrations but not on the transcripts of proteins involved in phospholipid biosynthesis (glycerol-3-phosphate acyltransferase) and cholesterol metabolism at intestinal and hepatic levels. Hepatic and muscular fatty acid profiles reflected that of diets, despite the up-regulation of FADS2 transcripts. Overall, this study demonstrated that dietary carbohydrates mainly affected carbohydrate metabolism, lipogenesis and LC-PUFA biosynthesis, whereas effects of dietary lipid source were mostly related with tissue fatty acid composition, plasma phospholipid and cholesterol concentrations, and LC-PUFA biosynthesis regulation. Interactions between dietary macronutrients induced modifications in tissue lipid and glycogen content.

Effects of dietary lipid sources on growth performance, lipid metabolism and antioxidant status of juvenile Russian sturgeonAcipenser gueldenstaedtii

Six isonitrogenous and isoenergetic diets were used to test the influence of lipid source on growth performance, antioxidant status and lipid metabolism of juvenile Russian sturgeon, Acipenser gueldenstaedtii. Each diet was supplemented with 90 g kg−1 of lipid from each of six sources including fish oil (FO), beef tallow (BT), sunflower oil (SO), linseed oil (LO) and equal combinations of FO + SO + BT (FSB) or LO + SO + BT (LSB). After 56 days, fish fed LSB demonstrated highest weight gain, specific growth rate and lowest hepatosomatic index among all groups. The n-6 polyunsaturated fatty acids (PUFAs) in the whole fish were highest in the SO group, and n-3 PUFAs were highest in fish fed LO. The fish fed FO contained highest n-3 highly unsaturated fatty acids. Triglyceride in the serum of fish fed LSB was lowest, but was not significantly different from that in the SO group. Triglyceride in the serum of fish fed FO and BT was highest among all groups. Lipase, malate dehydrogenase and lipoprotein lipase activities were highest in fish fed LSB. Serum malondialdehyde in fish fed LSB was significantly lower than in fish fed FO or SO, but no significant differences were found among fish fed LSB, BT, LO or FSB. Fish fed LSB showed higher catalase activity and total antioxidant capacity than fish fed FO or FSB. This study indicates that linseed, sunflower oil and BT mixed oil are a suitable lipid source and can benefit growth performance and antioxidation in juvenile sturgeon.

Growth performance, tissue composition, and gene expression responses in Atlantic salmon (Salmo salar) fed varying levels of different lipid sources

We investigated the influence of dietary fatty acid (FA) composition on growth performance, muscle tissue FA composition, and lipid-related hepatic gene expression in Atlantic salmon. Currently the commercial feed industry primarily uses terrestrial-based fats and oils as the main lipid component in the diet, with minimal provision of fish oil (FO). Therefore, we compared the growth and tissue FA response of salmon smolts (mean initial weight 256gfish−1) after 16weeks on three different terrestrial-based diets, with inclusion at three increasing levels of substitution with FO. The lipid sources used in this study were: FO, camelina oil (CO), canola oil (CA), and camelina oil with poultry fat (CO+PF). The terrestrial-based lipid sources had different FA signatures, on account of varied proportions of the C18 FA: 18:2n−6, 18:3n−3, or 18:1n−9. Inclusion of terrestrial FA and removal of marine FA (20:5n−3, 22:6n−3) were reflected in the FA composition of the muscle, and affected growth performance (based on lipid source and inclusion level) and hepatic gene expression of several lipid metabolism-relevant genes. Multiple regression analysis revealed that dietary lipid source affected growth performance, even when inclusion level (as a replacement of FO) was not a factor; suggesting that either inclusion or removal of certain FA in particular lipid sources, even at minimal levels, influenced growth performance. A breakpoint analysis of final weight indicated that dietary levels of <1% each of 20:5n−3 and 22:6n−3 resulted in lower final weight. A multidimensional scaling plot showed that the muscle tissue FA composition of salmon fed diets with CO were distinguishable from salmon fed CA and PF, mainly on account of 18:3n−3, while salmon fed FO were distinct from the terrestrial-based treatments. Salmon fed CO diets maintained 22:6n−3 levels in muscle tissue, and increased in n−3 and n−6 intermediary biosynthesis products in the muscle suggesting endogenous production of 22:6n−3 via dietary 18:3n−3. In addition, significant correlations were observed among dietary and/or muscle tissue FA with elovl2, fadsd5, and srebp1 transcript expression, further supporting FA biosynthesis. Significant relationships were also observed among lipid and cholesterol metabolism-related genes with dietary and tissue sterol and 20:4n−6 content, and they were most often related to cholesterol catabolism (or reduction in synthesis), such as hmgcr, dhcr7, and pparβ1. Correlations among gene expression with dietary and tissue lipid classes and FA content provided evidence to support the link between dietary FA input and phenotypic response.

Dietary oils influence ovary and carcass composition and embryonic development of zebrafish

To evaluate the effect of different dietary lipids on zebrafish reproduction, we examined parameters including ovary and carcass composition, oestradiol (E2) levels, eclosion rate and embryonic development. In our study, zebrafish were subjected to a 5-month feeding trial whereby olive (OLV), linseed (LIN), fish (FIS) or corn (CRN) oil were used to compose four isonitrogenous and isoenergetic diets. A positive correlation was found between ovary EPA and whole-body E2 concentration (P = 0.005). The developmental dynamics was affected by dietary lipids and embryos from CRN treatment females; which had higher percentage of ARA in ovary (1.48 ± 0.44%) (P = 0.015), developed faster at 8–9 h postfertilization (hpf) than the ones originated from females receiving other diets (P = 0.0069). This effect was not sustained during later observation periods, suggesting ARA may act as a modulator of developmental dynamics only during initial phases. There was no clear effect of dietary lipid source on ovary protein content (P = 0.304) and eclosion rates at 72 hpf (P = 0.0623). Dietary fatty acids play an important role in reproductive outcome; however, additional studies are necessary to elucidate the mechanisms by which HUFA affect embryonic development.

Cold storage effects on flesh quality of rainbow troutOncorhynchus mykiss(Walbaum, 1792) fed diets containing different vegetable oils

The intention of this experiment was to assess the effects of different sources of dietary lipid on the fatty acid composition of the fillet and liver and the flesh quality traits of rainbow trout (Oncorhynchus mykiss) after a 70-day feeding period. Four iso-nitrogenous (approx. 51% crude protein) and iso-lipidic (approx. 14% crude lipid) experimental diets were formulated. The control diet contained only fish oil (FO) as the primary lipid source. In the other three dietary treatments, fish oil was replaced by 100% (LO30/SO35/SFO35) and 70% (FO30/LO35/SO35 or FO30/SO35/SFO35) sesame oil (SO), linseed oil (LO), or sunflower oil (SFO). Triplicate groups of 40 rainbow trout (~46 g) held under similar culture conditions were hand-fed daily to apparent satiation for 70 days. At the end of the feeding trials, no difference in growth performance among experimental groups was noted (P > 0.05). There were some differences in the proximate composition of fish fillets (P < 0.05): the eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) levels were highest in fish fed the control diet (P < 0.05); and EPA and DHA levels in fish fed the FO30/LO35/SO35 diet were closest to the control diet (P < 0.05). In contrast, fish fed the diet containing 100% plant oils (LO30/SO35/SFO35) had the highest level of total n-6 fatty acids in the fillet and liver. In a 12-day refrigerated storage at 1°C the thiobarbituric acid (TBA), trimethylamin nitrogen (TMA-N) and pH values gradually increased in all dietary groups (P < 0.05). The chemical indicators of spoilage, TBA, TMA-N, and pH values were within the limit of acceptability for human consumption.

Serum Lipids Profile of Growing Rats Feed with Different Sources of Lipids

IntroductionDiet lipid profile is important to prevent chronic diseases and improve the quality of life of individuals.Objectiveanalyze the effect of different sources of dietary lipids on sera triglycerides (TG), total cholesterol (TC) and fatty acid profile of growing rats.Methodsweanling Wistar rats were fed during 40 days with experimental diet containing: 15 Kcal of lipids % (F%) provided by butter (B group) and olive oil (O group). Control group(C) received diet according to AIN’93 (soy oil and F%=15). Sera levels of TG and TC were determined by enzymatic‐colorimetric method. Diets, serum fatty acids profiles were determined by gas chromatography. Statistical analysis used ANOVA and Dunnett/Kruskal‐Wallis as post tests (*p&lt;0.01).ResultsSera (mean±SD, mg/dL) TG B15=122.9±28.4*; O15=94.6±23.7; C=62.2±27.3; TC B=65.7±8.8; O=69.5±7,0; C=62.1±9.6. Results of fatty acids expressed as % Area (*p&lt;0.01) were: PALMITIC B=20.66±1.86* O=19.44±2.05 C=16.08±2.15 OLEIC B=19.26±1.97* O=20.42±3.51* C=11.29±2.27 LINOLEIC B=5.71±3.35* O=8.40±0.96* C=18.50±3.31 LINOLENIC B=0.33±0.16* O=0.35±0.15* C=0.81±0.22.ConclusionTG were statistical higher in B compared with C. Experimental groups B and O showed higher sera oleic acid levels with lower linolenic and linoleic levels compared to C. Conclusions: The increase of TG would be a consequence of the type of lipid received. The results of sera fatty acids suggest that it was exacerbated ω9 family with diminution of essential fatty acids. The sources of dietary lipids provoked changes in sera fatty acids profiles.Support or Funding InformationSupported by UBACyT 20020120200068.

Uncoupling EPA and DHA in Fish Nutrition: Dietary Demand is Limited in Atlantic Salmon and Effectively Met by DHA Alone.

Due to the scarcity of marine fish oil resources, the aquaculture industry is developing more efficient strategies for the utilization of dietary omega-3 long-chain polyunsaturated fatty acids (n-3 LC-PUFA). A better understanding of how fish utilize EPA and DHA, typically provided by fish oil, is needed. However, EPA and DHA have different physiological functions, may be metabolized and incorporated into tissues differently, and may vary in terms of their importance in meeting the fatty acid requirements of fish. To address these questions, Atlantic salmon were fed experimental diets containing, as the sole added dietary lipid source, fish oil (positive control), tallow (negative control), or tallow supplemented with EPA, DHA, or both fatty acids to ~50 or 100% of their respective levels in the positive control diet. Following 14 weeks of feeding, the negative control diet yielded optimum growth performance. Though surprising, these results support the notion that Atlantic salmon requirements for n-3 LC-PUFA are quite low. EPA was largely β-oxidized and inefficiently deposited in tissues, and increasing dietary levels were associated with potential negative effects on growth. Conversely, DHA was completely spared from catabolism and very efficiently deposited into flesh. EPA bioconversion to DHA was largely influenced by substrate availability, with the presence of preformed DHA having little inhibitory effect. These results clearly indicate EPA and DHA are metabolized differently by Atlantic salmon, and suggest that the n-3 LC-PUFA dietary requirements of Atlantic salmon may be lower than reported and different, if originating primarily from EPA or DHA.