Dietary Supplementation of Tetracarpidium conophorum (African Walnut) Seed Enhances Muscle n‐3 Fatty Acids in Broiler Chickens

The influence of dietary Tetracarpidium conophorum (African Walnut) seed meal (TCSM) on fatty acids, productivity parameters, and physicochemical properties of breast and thigh muscles in broiler chickens are assessed. A total of 180, 28‐d‐old Arbor acre broiler chickens are randomly assigned to dietary treatments containing 0% (control), 2.5%, and 5% w/w TCSM, fed for 28 d, and euthanized. Dietary TCSM reduces (p < 0.05) feed intake, body weight gain (BWG), carcass weight, and abdominal fat. Diet does not affect feed efficiency and hematological parameters. The control birds have higher (p < 0.05) serum total cholesterol and triglycerides than do the supplemented birds. Diet has no effect on pH, water holding capacity, carbonyl and malondialdehyde contents, and organoleptic properties of breast and thigh muscles. The 5% TCSM has higher redness in breast muscle than do other treatments. Dietary TCSM improves (p < 0.05) the concentration of C18:3n‐3 (4.80–8.76% vs 1.56%), C20:5n‐3 (0.54–0.79% vs 0.39%), C22:5n‐3 (0.64–0.89% vs 0.18%), and C22:6n‐3 (0.75–0.97% vs 0.19%), and reduces (p <  0.05) the fat content (2.15–2.45% vs 3.15%) in breast and thigh muscles. Dietary TCSM enhances muscle n‐3 fatty acids without instigating oxidative deterioration, but reduces BWG in broiler chickens. Practical Application: Albeit that broiler meat is rich in polyunsaturated fatty acids (PUFA), its omega 6 (n‐6)/omega 3 (n‐3) is >4. Elevated n‐6/n‐3 could have adverse effect on human physiology thereby promoting the pathogenesis of certain diseases. This heightens the need to enhance the n‐3 PUFA content of broiler meat. Dietary TCSM induced up to a fourfold increase in n‐3 PUFA content of the breast and thigh muscles in broiler chickens. Moreover, dietary TCSM induced up to a tenfold decrease in the n‐6/n‐3 of the breast and thigh muscles in broiler chickens. This finding assumes great significance because the health concerns regarding dietary fat are the foremost factors responsible for the bad image suffered by meat. These results provide insights on the potential of TCSM to improve the nutritional quality without compromising the oxidative shelf life, organoleptic traits, and physicochemical properties of broiler meat.     

In Vitro Antioxidant Properties of Berry Leaves and Their Inhibitory Effect on Lipid Peroxidation of Thigh Meat from Broiler Chickens

The present study is designed to evaluate the antioxidant compounds from bilberry, cranberry, and raspberry leaves in connection with their radical scavenging activities, and their potential in inhibiting the lipid peroxidation of thigh meat from broiler chickens. For this purpose, plant extracts are analyzed regarding the content in bioactive compounds, antioxidant properties analysis including 1,1‐diphenyl‐2‐picrylhydrazyl, superoxide, hydrogen peroxide, and hydroxyl radical‐scavenging activities. Lipid peroxidation is induced by an Fe⁺³/ascorbic acid system and the inhibitory effects of plants extracts are assessed using thiobarbituric reactive substances (TBARS) as biomarkers for quantifying lipid oxidation in meat. The overview of the analyzed antioxidant compounds shows that cranberry leaves present the highest concentrations of vitamin E, β‐carotene, lutein and zeaxanthin, and polyphenols and a total antioxidant capacity with 52% higher than bilberry and 360% than raspberry. Bilberry leaves extract shows the strongest effect (p  < 0.0001) in inhibiting meat lipid peroxidation. Practical Applications: The results demonstrate the positive effect of the selected berry leaves in the oxidative stability of broiler chicken meat under in vitro conditions, and may be suggested as an alternative source of natural antioxidants for animal nutrition, with benefits in inhibiting and delaying oxidation, and also enhancing the nutritional value of meat.     

Regulation of the α-tocopherol transfer protein in mice: Lack of response to dietary vitamin E or oxidative stress

The α-tocopherol transfer protein (TTP) plays an important role in the regulation of plasma α-tocopherol concentrations. We hypothesized that hepatic TTP levels would be modulated by dietary vitamin E supplementation and/or by oxidative stress. Mice were fed either a High E (1150 mg RRR-α-tocopheryl acetate/kg diet) or a Low E (11.5 mg/kg diet) diet for 2 wk. High E increased plasma and liver α-tocopherol concentrations approximately 8- and 40-fold, respectively, compared with Low E-fed mice, whereas hepatic TTP increased approximately 20%. Hepatic TTP concentrations were unaffected by fasting (24 h) in mice fed either diet. To induce oxidative stress, chow-fed mice were exposed for 3 d to environmental tobacco smoke (ETS) for 6 h/d (total suspended particulate, 57.4±1.8 mg/m3). ETS exposure, while resulting in pulmonary and systemic oxidative stress, had no effect on hepatic α-tocopherol concentrations or hepatic TTP. Overall, changes in hepatic TTP concentrations were minimal in response to dietary vitamin E levels or ETS-related oxidative stress. Thus, hepatic TTP concentrations may be at sufficient levels such that they are unaffected by either modulations of dietary vitamin E or by the conditions of environmentally related oxidative stress used in the present studies. The first and second investigators contributed equally to this work.     

Growth Performance,Carcass Characteristics,Fatty Acid Composition,and Blood Biochemical Parameters of Lamb Fed Diet with the Addition of Lingonberry Leaves and Oak Bark

The aim of the study is to determine the effect of natural additives supplemented to the lamb diet on lamb performance, fatty acid (FA) composition of edible parts of lambs, and biochemical plasma indices. The study is carried out on 18 male lambs, allocated to three groups in a randomized complete block design. Control animals (CON) are fed a basic diet, while the experimental lambs additionally receive lingonberry leaves (VVI) or oak bark (QUE) (10 g d^?1), as a different source of tannins. Supplementing lambs with the VVI diet decreases fat content in the longissimus dorsi muscle (MLD). The VVI diet decreases monounsaturated fatty acid (MUFA) concentration (including C18:1 cis‐9) in the MLD, increases the proportion of C16:0, C16:1, C17:1, and C22:6 n‐3 in the semitendinosus muscle, as well as increases the n‐6/n‐3 ratio and thrombogenic index in the liver. The addition of QUE to lamb diets decreases C17:1 concentration and increases the content of C18:1 trans‐11 in the MLD. Tannins‐enriched diets increase low density lipoprotein concentrations in the blood plasma. The VVI diet increases the activity of alkaline phosphatase, while QUE supplementation decreases gamma‐glutamyl transferase activity in blood plasma. Modifications of FA composition in lamb tissues may suggest an indirect effect of tannins on FA ruminal biohydrogenation. Practical Applications: The use of VVI and QUE in lamb nutrition as natural resources is of a great interest to scientists. The present study shows that primarily VVI addition to lamb diets affects the quality of meat, due to higher proportion of catechin than QUE. Decreased concentration of fat, as well as increased proportion of C22:6 n‐3 and desirable fatty acids (including MUFA, polyunsaturated fatty acid, C18:0) after VVI supplementation increases health‐promoting properties of lamb meat and is related to humans. However, the presence of biologically active substances (tannins) in the examined additives makes it necessary to further research and discover their full potential in many areas.     

Effect of dietary vitamin E levels on fatty acid profiles and nonenzymatic lipid peroxidation in the guinea pig liver

Guinea pigs were fed for five weeks with three diets containing different levels of vitamin E: LOW (but nondeficient, 15 mg of vitamin E/kg diet), MEDIUM (150 mg/kg diet), and HIGH (1,500 mg/kg diet). Dietary vitamin E supplementation did not change oxidative stress indicators in the hydrophilic compartment but increased liver α-tocopherol in a dose-dependent way and strongly decreased sensitivity to nonenzymaticin vitro liver lipid peroxidation. This last effect was already observed in group MEDIUM, and no further decrease inin vitro lipid peroxidation occurred from group MEDIUM to group HIGH. The protective effect of vitamin E againstin vitro lipid peroxidation was observed even though an optimum dietary concentration of vitamin C for this animal model was present in the three different vitamin E diets. Both HIGH and LOW vitamin E decreased percentage fatty acid unsaturation in all phospholipid fractions from membrane origin in relation to group MEDIUM. The results, together with previous information, show that both vitamin E and vitamin C at intermediate concentrations are needed for optimal protection against lipid peroxidation and loss of fatty acid unsaturation even in normal nonstressful conditions. These protective concentrations are higher than those needed to avoid deficiency syndromes.     

Antioxidant activity of lipid-soluble phenolic diterpenes from rosemary

A high-performance liquid chromatography method for analyzing the phenolic diterpenes present in rosemary (Rosmarinus officinalis L.) and commercial rosemary extracts is reported. Carnosic acid was the major phenolic diterpene present in rosemary leaves, with lesser amounts of 12-methoxycarnosic acid and carnosol. Several commercial rosemary extracts also were analyzed by this method, and in addition to these three compounds other phenolic diterpenes, such as 7-methoxyrosmanol, 7-methoxy-epirosmanol, and rosmanol, were found in some samples. These latter three compounds seem to be artifacts, produced from carnosic acid by oxidation and cyclization. The major phenolic diterpenes were isolated, and their relative antioxidatn activities in soybean oil were measured by the Rancimat. The potency of carnosic acid was more than twice that of any other compound. The antioxidant activity of pure carnosic acid was compared to butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and tertiary butylhydroquinone (TBHQ) and was several times greater than BHT and BHA but less than TBHQ. Nuclear magnetic resonance data for several of the compounds that were incompletely characterized in previous literature are reported.     

Dietary modifications of animal fats: status and future perspectives

The purpose of modifying animal fats is to produce high quality products, which meet the dietary recommendations for a reduced intake of fat in the human diet, notably that of certain saturated fatty acids and cholesterol, and an increased intake of mono- (MUFA) and polyunsaturated fatty acids (PUFA) in order to minimize the risk for obesity, cancer, cardiovascular, and other life-style diseases. The body fat of farm animals is partly synthesized from dietary carbohydrates, partly from dietary fatty acids. In monogastric animals, preruminants and poultry PUFAs are readily absorbed and deposited in the edible parts of the body and incorporated into egg yolk lipids. In ruminants, however, PUFAs are hydrogenated to mainly saturated fatty acids by the rumen microorganisms with some formation of MUFAs, trans-, odd-, branched chain, and conjugated fatty acids. The latter fatty acids are absorbed, deposited in adipose and muscle tissue and incorporated into milk lipids, unless dietary PUFAs are protected against hydrogenation. Thus, it is relatively easy to change the fatty acid composition of pork, poultry meat, lamb, and veal, whereas beef and milk can only be enriched significantly with PUFAs by manipulation. Products enriched with PUFAs are, however, prone to oxidation, and enrichment with antioxidants, notably with dietary vitamin E, is necessary in order to prevent the risk of oxidative damage.     

Soybean Oil and Selenium Yeast Supplementation in Quail's Diet: Productive Performance,Fatty Acid Profile,Enzyme Activity,and Oxidative Stability of Meat

The objective of this study is to evaluate the influence of different soybean oil (SO) and selenium yeast (SeY) levels in the diet of meat quails on productive performance, physicochemical, quality measurements, fatty acid profile, enzyme activity estimation, and oxidative stability of meat. A total of 288 one-day old commercial meat quails are allocated into four groups according to a completely randomized experimental design, with two levels of SO (1.5% and 3.0%) and SeY (0 and 0.15 mg kg⁻¹) in the feed. The supplementation period is 42 days. The use of up to 3% supplementation of SO in the diet improves (p < 0.05) the productive performance. The polyunsaturated acid content and thiobarbituric acid value in the meat are increased (p < 0.05) as an effect of the SO increase in the diet. The use of SeY in quail diets associates with 3% inclusion of SO and promotes improvements in the qualitative parameters of the quail meat. Therefore, the inclusion of 0.15 mg kg⁻¹ of SeY in the diets is a viable alternative for improving the oxidative stability of meat since it improves the qualitative parameters of quail meat in diets with a high inclusion of SO. Practical Applications: These results have practical applicability in the meat industry, since it is possible to change the lipid profile of this raw material, meeting the requirement of the consumer market for healthy foods, reducing the total cholesterol content, and nutritionally desirable, through enrichment with polyunsaturated fatty acids.     

Lower Concentration of n‐3 in the Red Blood Cells and Plasma of Lambs when their Dams were Fed a Diet High Compared with Low in n‐6 Fatty Acids at Joining

Feeding ewes a diet high in n‐6 in late gestation can affect fatty acid concentrations in the newborn lamb. The effect of feeding ewes a high n‐6 diet prior to conception and in early gestation on lamb n‐6 and n‐3 status has not previously been examined. The aim of the current study was to determine whether the concentration of n‐6 was higher and n‐3 was lower in lamb red blood cells (RBC) and plasma when Merino dams were fed a diet high in n‐6 either pre‐conception only or both pre‐conception and in early gestation. Dams were fed a diet low (silage) or high (oats/CSM) in n‐6 for either 6 weeks pre‐mating only or 6 weeks pre‐mating and 17 days post‐mating. The fatty acid status of lamb RBC and plasma was determined following birth and compared with dam fatty acids around parturition. The concentration of lamb RBC and plasma n‐3 was lower (p < 0.05) when dams received the high n‐6 compared with low‐n‐6 diet around mating, independent of the length of time of feeding. The concentration of n‐3 in lamb plasma was also higher when lambs were assessed as being likely rather than unlikely to have suckled prior to blood collection. Lamb RBC and plasma n‐3 fatty acids were lower when dams were fed the high compared with the low n‐6 diet for only a short time around mating. Transfer of fatty acids via the placenta and milk may account for the differences.     

Physicochemical Properties,Lipid Oxidation,and Fatty Acid Composition of Sausage Prepared with Meat of Young Nellore Bulls Fed a Diet with Lauric Acid

This study evaluates the quality of sausage obtained from the meat of Nellore cattle fed diets containing different levels (0, 5, 10, and 15 g per kg total DM) of lauric acid (C12:0) from palm kernel cake. A linear reduction (p ≤ 0.05) in lipid oxidation, as reflected by linear decreases in the lightness (L*), yellowness (b*), and saturation (C*) color parameters, is observed on days 7, 14, and 21 of maturation of sausage, and these decreases are accompanied by linear increases in the redness (a*) color and the linoleic (C18:2n–6) and linolenic (C18:3n–3) fatty acid contents. The inclusion of lauric acid in the diet induces linear reductions in the shear force and cooking loss and does not significantly affect various indices, including the centesimal composition, water activity, water holding capacity, composition of most fatty acids (FA), hypocholesterolemic‐to‐hypercholesterolemic FA ratio, atherogenicity, thrombogenicity, and desirable fatty acids. The use of dietary lauric acid from palm kernel cake is recommended at doses up to 15 g per kg because its presence reduces lipid oxidation and improves color parameters, softness, and linoleic and linolenic FA without affecting the FA composition of sausage from Nellore bull's meat. Practical applications : Sausages are products manufactured from chopped or ground meats packaged into animal casings. This product appeared in Brazil through the adaptation of traditional recipes brought by German and Italian immigrant families to weather conditions and the national palate. However, due to its production characteristics, sausage can become a product with lipid characteristics that are undesirable for human consumption. The inclusion of lauric acid (C12:0) in the animal diet might change the biohydrogenation process in the rumen, improve the quality of the deposited FA and reduce lipid oxidation in sausage manufactured from meat. The FA composition and physicochemical properties of sausage predict its acceptance by the consumer market. An optimal advantage would be achieved if these products can be used as not only preservatives but also functional ingredients with antioxidant properties and products for the treatment of metabolic syndrome and cardiovascular diseases through atherogenic action.     

Simultaneous extraction of rosemary and spinach leaves and its effect on the antioxidant activity of products

Mixed vegetal extracts are interesting target of new products as nutraceuticals, superior ingredients for the design of functional food, singular ingredients for cosmetics, etc. In this work the extraction of a mixture of spinach and rosemary leaves (50 wt.% of each plant) was investigated in terms of its antioxidant activity, and compared with the extraction of the separate species. Phenolic diterpenes of rosemary and carotenoids of spinach were target compounds due their recognized biological activities. Two different extraction techniques were applied, namely pressurized liquid extraction using hexane at two different temperatures (100 and 150 °C) and supercritical fluid extraction with pure carbon dioxide at 40 °C and two different pressures (20 and 30 MPa). For each extraction technique and conditions three different raw materials were employed: spinach leaves, rosemary leaves and the mixture 50:50 of spinach and rosemary leaves.The antioxidant activity of the samples produced was evaluated with the ABTS assay and showed to be enhanced when the species are simultaneously extracted, with antioxidant values around 20% higher than the values corresponding to mixing the extracts obtained by separate. A possible synergic effect between carotenoids and phenolic diterpenes was studied, although no specific synergic activity could be observed. However, the enhanced antioxidant activity could be attributed to a definite increase of the concentration of carnosic acid, which was observed in the samples produced by the simultaneous extraction.     

The Synergism of Biochemical Components Controlling Lipid Oxidation in Lamb Muscle

Lipid oxidation of M. longissimus lumborum in fresh or vacuum packaged (aged) lamb meat stored at 3 °C for 0 or 4 weeks, respectively and displayed under refrigerated conditions for a further 4 days was assessed by measuring the concentration of malondialdehyde (MDA) in meat using the thiobarbituric acid reactive substances procedure. The effects of vitamin E, heme iron and polyunsaturated fatty acids (n-6 and n-3) on lipid oxidation were examined. Results showed a strong positive relationship between heme iron, n-6 and n-3 fatty acids and lipid oxidation when vitamin E was below 2.95 mg/kg muscle. When lipid oxidation was related to vitamin E concentration and the other three variables, respectively, any increase in heme iron or n-6 or n-3 fatty acids concentration did not influence lipid oxidation. Management of diet to elevate muscle vitamin E concentration above 3.45 mg/kg muscle is beneficial to maintain the level of lipid oxidation below 2.4 mg MDA/kg muscle in meat stored for up to 4 weeks. This demonstrates that vitamin E concentration in muscle has a greater influence on controlling lipid oxidation in muscle tissues than do heme iron or polyunsaturated fatty acids.     

Metabolic effects of selenium as related to vitamin E

Trace amounts of dietary selenium, which prevent certain vitamin E deficiency symptoms, have been found to affect the composition of chick tissues. Both selenium and vitamin E increased liver coenzyme A levels to normal when cystine was omitted from the diet. Liver and plasma total fatty acids were unaltered by selenium but vitamin E increased the arachidonic acid content slightly. There was no effect of either selenium or vitamin E on total lipid, cholesterol, phopholipid or coenzyme Q in liver. Low dietary levels of either selenium or vitamin E, which were insufficient in preventing deficiency symptoms, completely eliminated mortality from toxic amounts of a dietary antioxidant. The ability of dietary selenium to reducein vitro lipid peroxidation in chick liver homogenates was not demonstrable with rat liver. Presented at the AOCS meeting in Toronto, Canada, 1962.     

Effects of tocopherols and tocotrienols on the inhibition of autoxidation of conjugated linoleic acid

The effect of eight vitamin E homologues, i.e. α‐, β‐, γ‐, and δ‐tocopherol and α‐, β‐, γ, and δ‐tocotrienol, on the inhibition of autoxidation of conjugated linoleic acid (CLA) were investigated. The oxidation was carried out in the dark for 21 days at 50 °C and monitored by peroxide values (PV) and TBA values. The levels of the individual vitamin E homologues in CLA during storage were determined by HPLC. γ‐Tocopherol exhibited the highest antioxidant activity among the homologues tested in this study when the antioxidant activities of the individual homologues in CLA were compared by PV. The order of antioxidant activity of eight homologues was γ‐tocopherol > δ‐tocopherol = δ‐tocotrienol ≥ γ‐tocotrienol > β‐tocopherol = β‐tocotrienol > α‐tocopherol = α‐tocotrienol. The degradation rates of α‐tocopherol and α‐tocotrienol were faster than those of the other homologues, whereas δ‐tocopherol had the highest stability in CLA during storage. All homologues exhibited an antioxidant activity by inhibiting the formation of secondary oxidation products. It appears that α‐tocotrienol and β‐tocotrienol have significantly higher antioxidant activities for secondary oxidation in CLA than α‐tocopherol and β‐tocopherol. Meanwhile, the other homologues, namely γ‐tocopherol, γ‐tocotrienol, δ‐tocopherol, and δ‐tocotrienol, exhibited similar antioxidant activity for secondary oxidation in CLA.     

Effect of omega fatty acid-rich oil blend supplementation on the growth,carcass, meat quality,and gene expression of Barbari goats

This study investigated the effect of supplementing omega fatty acids-rich oil blend, composed of sunflower oil (1.5% and 3.0%), linseed oil (1.5% and 3.0%), and FineXNV1810 (20 g) on the carcass, meat quality, fatty acid profile, and genes (peroxisome proliferator-activated receptor-α, stearoyl-CoA desaturase, acetyl-CoA carboxylase, hydroxy-3-methylglutaryl coenzyme A, and leptin) of Barbari goats. The goat kids (n = 18) were divided into three groups, namely, group A: basal diet; group B: basal diet + oil blend level 1; and group C: basal diet + oil blend level 2, and subjected to the feeding trial for 120 days followed by slaughter and meat quality studies. No treatment effect was recorded in carcass characteristics, pH, water holding capacity, and proximate composition of meat. However, a significant (p < 0.05) treatment effect was observed in cooking loss, lightness, yellowness, and shear force values of meat. There were significant differences (p < 0.05) in linoleic acid, α-linolenic acids, conjugated linoleic acid (CLA), polyunsaturated fatty acids (PUFA), n − 3 and n − 6 PUFA, PUFA/saturated fatty acids and n − 6/n − 3 ratios, and thrombogenic index among groups. An upregulation of the studied genes in the supplemented groups was observed. There were upregulations in the studied genes in the supplemented groups. Practical applications: Goat meat is in great demand the world over, especially in tropical countries, including India, and does not carry any social or religious prohibition. Although goat meat has relatively less fat, consumers express their concern over the presence of undesirable fatty acids. The present study shows that the fatty acid configuration of goat meat can be improved by a dietary supplementation of an oil blend rich in omega fatty acids. The amount of n − 3 PUFA, n − 6 PUFA, and CLA in goat meat was significantly increased due to the dietary oil blend making it healthy for the consumers. Moreover, the dietary oil blend at the studied levels did not significantly affect the growth and meat quality parameters of the goats. Thus, the studied approach can be successfully followed to produce healthier goat meat.     

Pea (<Emphasis Type="Italic">Pisum</Emphasis><Emphasis Type="Italic">sativum</Emphasis> L.) Seeds as an Alternative Dietary Protein Source for Broilers: Influence on Fatty Acid Composition,Lipid and Protein Oxidation of Dark and White Meats

An experiment was conducted to evaluate the production parameters, breast and leg muscle fatty acid composition and lipid and protein oxidative stability of broilers fed peas (Pisum sativum L.). The trial involved 120 birds (Hubbard strain) allotted to two groups: group I—control group, fed a basal diet containing soybean meal (195 g kg⁻¹) as the main protein source; whereas group II—experimental group fed diet containing peas (400 g kg⁻¹) as a substitute for conventional soybean. No significant differences were observed for body weight, feed intake or feed conversion ratio (P > 0.05). The total lipids were lower (P < 0.05) in the breast and leg muscles of broilers fed peas. The content of total n-3 polyunsaturated fatty acids were higher (P < 0.05) in the white and dark meat of birds fed the pea diet compared with soybean control diet. After 7 days of refrigerated storage, the levels of thiobarbituric acid-reactive substances, lipid hydroperoxides and carbonyl proteins expressed as dinitrophenylhydrazine were similar (P > 0.05) in white and dark meat of chicks fed either diet. The data indicates that dietary pea inclusion does not cause detrimental changes in lipid and protein oxidation of poultry dark and white meats, suggesting the possibility of replacing soybean meal with peas.     

Dietary ALA,But not LNA,Increase Growth,Reduce Inflammatory Processes,and Increase Anti‐Oxidant Capacity in the Marine Finfish Larimichthys crocea

Whilst aquaculture feed is increasingly formulated with the inclusion of plant oils replacing fish oil, and increasing research effort has been invested in understanding the metabolic effects of reduced dietary n‐3 long chain poly unsaturated fatty acids (n‐3 LC‐PUFA), relatively little information is available on the potential direct metabolic roles of dietary alpha‐linolenic acid (ALA, 18:3n‐3) and alpha‐linolenic acid/linoleic acid (LNA, 18:2n‐6) ratio in cultured marine finfish species. In this study, four plant oil based diets, with varying ALA/LNA ratio (0.0, 0.5, 1.0 and 1.5) were fed to juvenile large yellow croakers (Larimichthys crocea) and compared to a fish oil‐based control diet (CD) to evaluate the resulting effects on growth, nonspecific immunity, anti‐oxidant capacity and related gene expression. High dietary LNA negatively impacted fish growth performance, nonspecific immunity and antioxidant capacity, but growth and immunity were maintained to levels comparable to CD by increasing the ratio of dietary ALA/LNA. The over‐expression of genes associated with inflammation (cyclooxygenase‐2 and interleukin‐1β) and fatty acid oxidation (carnitine palmitoyl transferase I and acyl CoA oxidase) in croakers fed high concentrations of LNA were reduced to levels comparable to those fed CD by increasing dietary ALA/LNA. This study showed that dietary ALA, by increasing the overall n‐3/n‐6 PUFA ratio, exerts direct anti‐inflammatory and antioxidant effects, similar to those exerted by dietary n‐3 LC‐PUFA.     

Effect of dietary organic selenium on fatty acid composition in nutria (Myocastor coypus Mol.) livers

Young, female nutrias (n = 13) were fed a diet supplemented with 0.36 mg/kg selenium in selenium‐enriched yeast (SeY; Sel‐Plex; Alltech, Inc., Nicholasville, KY) for 60 days (total Se concentration in the basal diet was ～0.1 mg/kg). Concentrations of fatty acids (FA) in the liver were compared to those of nutrias on a control diet (n = 11). Animals were sacrificed at 8 months of age and liver samples (approximately 30 g) were collected. The gas‐chromatographic analysis of tissue samples from the experimental group revealed a significant decrease in saturated fatty acids (p<0.001), monounsaturated fatty acid (p = 0.006), and polyunsaturated fatty acid (PUFA) (p = 0.02) compared to controls. The linoleic and linolenic acids, which are precursors of n‐6 and n‐3 PUFA, respectively, were significantly lower (p = 0.01 and p<0.001, respectively) in the supplemented group. The n‐6 to n‐3 PUFA ratio was significantly affected (p = 0.001) by the SeY dietary supplement (13.17 vs. 8.93, respectively).     

Supplementation with Docosahexaenoic Acid and Vitamin E Improves Hepatic Triglyceride Accumulation Induced by High-Fat Diet in Mice

The study aims to investigate the effect of combined supplementation with docosahexaenoic acid (C22:6 n-3, DHA) and vitamin E (VE) on the oxidative stress and liver triglycerides (TG) accumulation induced by high-fat diet (HFD) in mice. C57BL/6J mice are fed either a control diet or an HFD for 8 weeks. Animals are supplemented with DHA, VE, or DHA + VE, respectively. Supplementation with DHA alone shows significant improvement in oxidative stress and hepatic steatosis in mice. Supplementation with DHA significantly reduces the liver TG and total cholesterol contents, and the alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels, compared with the HFD. Supplementation with DHA also significantly decreases the mRNA expression level of sterol regulatory element-binding protein 1C. However, supplementation with VE alone does not show improvement in oxidative stress and hepatic steatosis. DHA + VE supply obtains a superior effect in alleviation of hepatic steatosis than DHA supplementation alone in mice fed by HFD. The efficacy of DHA potentiated by VE can be due to that VE enhances the effect of DHA in decrease of ALT and AST levels and increase of antioxidant enzyme activity and glutathione level in mice fed by HFD. Practical Applications: Supplementation with DHA significantly improves the oxidative stress and hepatic steatosis induced by HFD in mice. The efficacy of DHA in the alleviation of hepatic steatosis induced by HFD is potentiated by VE. These findings may provide a rational basis for the use of DHA and VE co-supplementation in patients with liver steatosis.     

Dietary saturated and omega‐3 fatty acids affect growth and fatty acid profiles of Malaysian mahseer

The current study was conducted to determine optimal levels of dietary saturated fatty acids (SFA), n‐3 PUFA and to study potential n‐3 sparing effect of dietary SFA for Malaysian mahseer Tor tambroides. Juvenile T. tambroides were fed four trial diets with similar basal composition but different oil mixtures in a 2 × 2 factorial experimental design for 10 weeks. The two factors were the levels of dietary SFA and the levels of dietary n‐3 PUFAs. Growth performance and fatty acid profile of tissues were analyzed at the end of the experiment. Significant differences in growth performance were observed among treatments, and fish fed the diet low in n‐3 and high in SFA showed the best growth performance. T. tambroides fed the high n‐3 diets showed a significantly higher (p<0.05) muscle total n‐3 PUFA content compared to fish fed the low n‐3 diets. The highest 22:6 n‐3 and total n‐3 PUFA content of the liver were also observed in fish fed the low n‐3 and high SFA diet. However, the significant interaction (p<0.05) between dietary SFA and n‐3 PUFA levels was observed for the total n‐3 PUFA content of both muscle and liver tissues, suggesting an n‐3 sparing action by dietary SFA. The results of this study suggest that 2.5% n‐3 PUFA in the diet of T. tambroides, with an SFA to n‐3 ratio of 15.3, is sufficient to provide the best growth performance and to retain the n‐3 content of tissues. Practical applications: The continuous increase of world population and growth of aquaculture industry put severe pressure on the marine resources such as fish oil and fishmeal. Here we show that fish oil can be substituted with palm oil, a cheaper and more available source of oil in tropical countries, in the diet of Malaysian mahseer without a reduction of growth. Moreover, palm oil as a source of SFA may spare omega‐3 in the fish tissues. Omega‐3 is an essential fatty acid for humans as final consumer of edible fish.