Saturated Fatty Acids In Muscle Research Articles

Altering the ratio of palmitic, stearic, and oleic acids in dietary fat affects nutrient digestibility, plasma metabolites, growth performance, carcass, meat quality, and lipid metabolism gene expression of Angus bulls

This study evaluated the effects of changing the ratio of palmitic, stearic, and oleic acids in dietary fat on nutritional metabolism, growth performance, and meat quality of finishing Angus bulls. Bulls received the following three treatments: (1) a control diet without fat supplement (CON), (2) CON + mixed fatty acid supplement (58% C16:0 + 28% cis-9 C18:1; MIX), (3) CON + saturated fatty acid supplement (87% C16:0 + 10% C18:0; SFA). In summary, both fat treatment diets simultaneously increased saturated fatty acids C16:0 (P = 0.025), C18:0 (P < 0.001) and total monounsaturated fatty acids (P = 0.008) in muscle, thus balancing the ratio of unsaturated to saturated fatty acids in muscle. MIX diet increased the digestibility of dry matter (P = 0.014), crude protein (P = 0.038), and ether extract (P = 0.036). SFA diet increased the daily gain (P = 0.032) and intramuscular fat content (P = 0.043). The high content of C16:0 and C18:0 in the SFA diet promoted weight gain and fat deposition of beef cattle by increasing feed intake, up-regulating the expression of lipid uptake genes and increasing deposition of total fatty acids, resulting in better growth performance and meat quality.

Effects of low protein diet with a balanced amino acid pattern on growth performance, meat quality and cecal microflora of finishing pigs.

The present study aimed to investigate the effects of low protein diets balanced with four amino acids on growth performance, meat quality and cecal microflora of finishing pigs. Fifty-four healthy hybrid barrows (Duroc × Landrace × Yorkshire) with an average body weight of 70.12 ± 4.03 kg were randomly assigned to one of the three dietary treatments with six replicate pens per treatment (three barrows per pen). The three dietary treatments included a normal protein diet (NP), a low protein diet (LP) and a very low protein diet (VLP). The average daily gain, average daily feed intake and feed conversion ratio of pigs were not significantly changed with the LP and VLP diets compared to the NP diet (P > 0.05). The water holding capacity and shear force of longissimus dorsi muscle were decreased, whereas the intramuscular fat content of the longissimus dorsi muscle was increased (P < 0.05) in pigs fed with the LP and VLP diets compared to the NP diet. The contents of saturated fatty acids in muscle were decreased (P < 0.05), whereas the content of polyunsaturated fatty acids in muscle was increased (P < 0.01) with the VLP diet compared to the NP diet. The contents of histamine, spermidine, spermine and tyramine of muscle were decreased with the VLP diet compared to the NP diet (P < 0.05). The relative abundance of Turicibacter, Terrisporobacter, Clostridium_sensu_stricto_1 and UCG-005 was higher (P < 0.05), whereas the relative abundance of Lactobacillus and Streptococcus was lower (P < 0.05) in pigs fed with the LP and VLP diets compared to the NP diet. Based on the correlation of cecal microbiota and cecal biogenic amine, the contents of tyramine, spermidine and histamine were negatively correlated with the abundance of Terrisporobacter (P < 0.01) and the content of histamine was positively correlated with the abundance of Lactobacillus (P < 0.01). Balanced with four essential amino acids, the VLP diet with crude protein levels decreased by > 4% increased the intramuscular fat content, changed the fatty acid and amino acid composition of longissimus dorsi muscle and the profile of cecum microbiota, and reduced the content of cecum bioamine, with no negative effect on the growth performance of pigs. © 2022 Society of Chemical Industry.

Effects of Different Roughage Diets on Fattening Performance, Meat Quality, Fatty Acid Composition, and Rumen Microbe in Steers.

This study aimed to evaluate different roughages on fatting performance, muscle fatty acids, rumen fermentation and rumen microbes of steers. Seventy-five Simmental crossbred steers were randomly divided into wheat straw group (WG), peanut vine group (PG) and alfalfa hay group (AG), with 5 replicates of 5 steers each. The results showed a highest average daily gain and lowest feed/gain ratio in AG group (P = 0.001). Steers fed alfalfa hay had the highest muscle marbling score and n-3 polyunsaturated fatty acid (PUFA), and also the rumen NH3-N and microbial protein (MCP) concentration among the three groups (P < 0.05). Correlation analysis showed that ruminal NH3-N and MCP were negatively correlated with muscle saturated fatty acid (SFA), while ruminal MCP was positively correlated with muscle PUFA and n-3 PUFA (P < 0.05). 16S rRNA analysis indicated that fed alfalfa hay decreased the abundance of Ruminococcaceae_UCG-001(P = 0.005). More importantly, muscle SFA deposition were positively correlated to the abundance of Ruminococcaceae_UCG-001 (P < 0.05), while the muscle PUFA and n-3 PUFA deposition were negatively correlated to it (P < 0.01). Therefore, alfalfa hay provides a better fattening effect on steers. Alfalfa rich in n-3 PUFA would reduce the abundance of Ruminococcaceae_UCG-001 involved in hydrogenation, increase the rumen protective effect of C18:3 n−3, which is beneficial to the deposition of muscle n-3 PUFA and PUFA.

Comparison of Muscle Quality of the Yellow Catfish Cultured in In-Pond Raceway Systems and Traditional Ponds

In order to understand the difference in muscle nutritional quality between yellow catfish (Pelteobagrus fulvidraco) cultured in in-pond raceway systems (IPR) and traditional ponds (TRP), two modes were used to culture the yellow catfish with the same initial body weight [average body weight (15.69 1 ± 2.28) g] for 60 days. The growth index, muscle texture characteristics, muscle nutritional components, amino acids and fatty acids of the fish were measured after the culture experiment. The results showed that the weight gain rate, specific growth rate and survival rate of IPR were significantly higher than TRP (p &lt; 0.05). The hardness, elasticity, chewiness and resilience of the yellow catfish cultured in IPR were significantly higher than those cultured in TRP (p &lt; 0.05). The crude protein content in the muscle of the yellow catfish cultured in IPR was significantly higher than that cultured in TRP (p &lt; 0.01), while the content of crude fat and water was significantly lower (p &lt; 0.01). The total amount of amino acids, essential amino acids and flavor amino acids of IPR were significantly higher than TRP (p &lt; 0.01). The percentages of saturated fatty acids in muscle of the yellow catfish cultured in IPR and TRP were 3.59% and 3.83%, respectively, and the percentages of unsaturated fatty acids were 96.41% and 96.17%, respectively. It was concluded that the nutritional quality of yellow catfish cultured in IPR was better than that of fish cultured in TRP.

Effects of Pantothenic Acid on Growth Performance, Oxidative Stress, and Lipid Content in High-Fat-Fed Megalobrama amblycephala

This study was to elucidate the effects of dietary pantothenic acid (PA) on growth, lipid metabolism, and antioxidant status in juvenile blunt snout bream Megalobrama amblycephala. Fish were fed with four experimental diets containing two lipid levels (5% and 11%) and two PA supplementation levels (24 mg kg-1 and 240 mg kg-1) for eight weeks. The results showed that diets containing 11% lipid significantly increased condition factor, mesenteric fat index, triacylglycerol (TG), and cholesterol (TCH) in the liver as well as total lipid content and TCH in the muscle ( P &lt; 0.05 ), but significantly decreased specific growth rate and whole-body protein ( P &lt; 0.05 ). As the dietary lipid level increased, hepatic antioxidant enzyme activities were significantly increased ( P &lt; 0.05 ) as well as malondialdehyde content ( P &lt; 0.05 ). Besides, cytosolic cytochrome c concentration was also significantly ( P &lt; 0.05 ) increased, while mitochondrial protein, cytochrome c, and Na+-K+-ATPase activities were significantly decreased ( P &lt; 0.05 ). There were no significant changes on growth performance and body composition of PA supplementation. Then, significantly negative ( P &lt; 0.05 ) interactions were observed between dietary lipid and PA supplementation on EPA, DHA, and EPA + DHA content of the muscle. Saturated fatty acid (SFA) and polyunsaturated fatty acid (PUFA) contents in the liver were significantly increased ( P &lt; 0.05 ) with dietary lipid level increased, while liver monounsaturated fatty acid (MUFA) was significantly decreased ( P &lt; 0.05 ). Muscle SFA, DHA, and EPA + DHA contents were significantly decreased ( P &lt; 0.05 ) when dietary fat level increased. Meanwhile, EPA, DHA, and EPA + DHA content was significantly decreased ( P &lt; 0.05 ) with dietary high PA supplementation. On the whole, a high PA supplementation level of 240 mg kg-1 could alleviate lipid content accumulated and oxidative damage induced by a high-fat diet.

Effects of different types of air supplementation on rainbow trout confined underwater

Salmonid are farmed far offshore in a submersible cage in China, and air supplementation in the swim bladder is an important issue while the fish are confined in the submersed cage. The objective of this study is to test the effects of different types of air supplementation on the growth, energy budget, and fatty acid composition of the rainbow trout, Oncorhynchus mykiss, confined underwater. The fish were divided into four groups with four replicates (63.84 ± 2.03 g, 13 fish per tank): The control group fish (Ctrl) were cultured in a glass fiber tank with airstone; The mesh group (ME) used a net in a tank to keep the experimental fish from the water surface, and an airstone above the net; The airstone group (AM) added an airstone under the net; And the airdome group (DM) added an airdome under the net. At the end of a 35-day trial, the final mean weight (70.00 ± 1.63 g), percent weight gain (7.09 ± 0.96%) and survival rate (76.92 ± 0.00%) of the fish in ME group were significantly lower than those in Ctrl group (91.54 ± 5.19 g, 43.49 ± 10.35% and 100.00 ± 0.00%, respectively). The final mean weight of AM group was significantly lower than that of Ctrl group, whereas there were no significant differences in other growth indexes between control group, DM and AM group. The proportion of feeding energy allocated to growth in ME group was the lowest, the proportion in AM was significantly higher than ME group and lower than Ctrl group, and there was no significant difference between those in DM and Ctrl groups. The muscle saturated fatty acid level in Ctrl group was significantly lower than those in other groups. In conclusion, the growth of rainbow trout confined underwater for 35 days will slow down due to lower proportion of feeding energy allocated to growth and higher proportion to respiration. The addition of an airdome or airstone can partially compensate for the growth of the fish confined underwater long time. Rainbow trout confined underwater can partially compensate for the loss of buoyancy through increasing the muscle saturated fatty acid content.

Optimizing the fatty acid profile of novel terrestrial oil blends in low fishmeal diets of rainbow trout (Oncorhynchus mykiss) yields comparable fish growth, total fillet n-3 LC-PUFA content, and health performance relative to fish oil

Identifying and effectively utilizing suitable, novel, terrestrial oil sources either alone or as blends to replace fish oil (FO) is a prerequisite for improving the sustainability of global aquaculture. Therefore, the present study evaluates several novel terrestrial oil blends (TOBs), optimized for their fatty acid profile, as alternatives to FO in low fishmeal diets fed to rainbow trout (Oncorhynchus mykiss) and describes the subsequent effects on fish growth, fatty acid composition and health. Insect oil (IO), genetically modified canola oil (CO), palm oil (PO) and linseed oil (LO) were used for the formulation of three TOBs viz., TOB-1 (30%IO+36%CO + 34%LO), TOB-2 (40%PO + 20%CO + 40%LO) and TOB-3 (50%TOB-1 + 50%TOB-2). Formulas TOB-1 and TOB-2 considered the total fatty acid profile based upon the general FO fatty acid profile, published fatty acid research for rainbow trout, and the fatty acid requirements of rainbow trout. A low fishmeal based basal diet containing 44% crude protein was formulated, and FO, TOB-1, TOB-2 and TOB-3 were incorporated in the basal diet to prepare the experimental diet groups, Control, TOB-1, TOB-2 and TOB-3, respectively. All experimental diets were fed to triplicate groups of rainbow trout juveniles (initial weight 7.9 ± 0.02 g) for 9 weeks. Growth performance (final weight, percent weight gain and specific growth rate) in TOBs fed groups were equal to the FO-based control group. Fish fed the TOB-3 diet consumed more feed followed by the control and TOB-1 diet groups. Significantly lower feed intake was observed in the TOB-2 diet group. Feed conversion ratio and protein efficiency ratio were not significantly influenced by dietary oil sources. Fish fed the control diet showed significantly higher hepatic lipid content compared to TOB groups, followed by TOB-2, TOB-3, and TOB-1, which was significantly lower in hepatic lipid content. Muscle lipid content and whole-body major nutrient compositions were not significantly influenced by the dietary oil sources. Fatty acid composition of muscle and liver reflected that of the diets. Maximum values for n3 LC-PUFAs (EPA and DHA), lauric acid (C12:0) and C18:3n-3 were observed in the FO, TOB-1 and TOB-2 groups, respectively. Except for C12:0, muscle saturated fatty acid contents were significantly lower in TOBs-based diet compared to the FO-based control diet fish. As expected, muscle C12:0 content was significantly higher in the TOB-1 group followed by the TOB-3 group. TOB-2 and control groups had significantly lower content of C12:0. The fillet total n-3 LC-PUFA was significantly higher in fish fed the control diet group followed by TOB-3 and TOB-2 groups, TOB-1 showed significantly lower content of total n-3 LC- PUFA. Hepatic delta-5 desaturase (Δ5fad), delta-6 desaturase (Δ 6fad) and fatty acid elongase-2 (Elovl-2) gene expressions were significantly influenced by dietary oil sources, where TOB-based groups showed higher Δ6fad and Elovl-2 expressions. Measured innate immunity and antioxidant markers were not affected by TOBs. Finally, we concluded that TOBs could serve as a substitute for FO in rainbow trout feed without negatively impacting performance. Moreover, fillet total n-3 LC-PUFA of TOB-fed fish satisfies the suggested daily serving for humans.

Chemical Form of Dietary Selenium Affects the Fatty Acids Profile and Oxidative Stability of Muscles of Broilers Supplemented with Lycopene and Oils

AbstractThe aim of this study is to determine the effects of the addition of different chemical forms of selenium (Se)—selenate (SeVI) or selenized yeast (SeY) to chickens’ diet containing equal amounts of fish (FO) and sunflower oils and lycopene (Lyc) on fatty acids (FA) profile and peroxidation yield in thigh muscles of chickens. FA profile is analyzed by gas chromatography coupled with mass spectrometry while content of malondialdehyde is determined by ultra‐fast liquid chromatography (UPLC) with photodiode detection. The diets containing SeY or SeVI increase the feed conversion efficiency of chickens compared with the control diet. SeY or SeVI added to the diet containing Lyc and FO stimulates concentrations of monounsaturated and polyunsaturated (PUFA) FA in muscles. Muscles of chickens fed a diet only with Lyc and FO have the highest indices of atherogenic (A‐SFA) and thrombogenic (T‐SFA) saturated FA and the highest ratios of A‐SFA and T‐SFA to all assayed FA. Dietary Se‐compounds also decrease the PUFA peroxidation indices in muscles compared with the diet containing only FO and Lyc. Therefore Se‐compounds may be added to diets including FO and Lyc to improve the growth parameters, nutritive value, and oxidative stability of chicken meat.Practical Applications: Poultry meat, which is characterized by high protein content of high biological value, high minerals and vitamins, and low collagen and fat content, is recommended as particularly desirable in a balanced diet to replace red and highly processed meat. Also, relatively good price makes this type of meat one of the most popular among consumers. The present study aims to check if inclusion of different chemical forms of selenium into chickens’ diets improves nutritional value of broiler meat. Feeding chickens with seleno‐supplements significantly enhances poultry production efficiency and nutritional value of broilers’ meat, because it favorably modifies FA composition (enhanced monounsaturated and polyunsaturated FA and decrease atherogenic and thrombogenic saturated FA in muscles) and reduces lipid oxidation in chickens’ meat. These results are important from the both producers’ and consumers’ point of view and correspond to contemporary nutritional recommendations.

Effects of methanolic leaf extract of Clinacanthus nutans on body weight and fatty acid composition in male obese mice

Background: In general, obesity refers to abnormal accumulation of fat associated with negative effects on health. It is a severe public health challenge in the 21st century in Southeast Asia and elsewhere in the world. Obesity results in reduced life expectancy and causes enormous economic and social problems. Therefore, the prevention and management of obesity is a key focus of population health. Aims and Objectives: This study aims to estimate the potential antiobesity effect of a methanolic leaf extract of Clinacanthus nutans (MECN) on high-fat diet-induced male mice by evaluating the body weight, visceral fat, and muscle saturated fatty acid (SFA) compositions (15.57%) (F = 16.24, P = 0.0001). Materials and Methods: A total of 60 4-week-old male Institute of Cancer Research mice were randomly assigned into two groups. Group 1 consists of 10 mice that were fed with normal diet (NC), while Group 2 consists of 50 mice that were fed with a high-fat diet (HFD) of 60% dietary energy from fat for 16 weeks. When these mice turned 20 weeks old, those in Group 2 were randomly assigned to five groups of 10 mice each, while animals from Group 1 continued to be fed with the Normal chow diet (NC). The five HFD groups derived from Group 2 were divided into mice treated with HFD only (HFDC), mice fed with an HFD and orlistat at 15.9 mg/kg (HFD + Orlistat). Mice in three other HFD groups were treated with MECN at 500 mg/kg (HFD + CN500), 1000 mg/kg (HFD + CN1000), and 1500 mg/kg (HFD + CN1500). All animals were then subjected to 21 days of the treatment. Results: The results showed that the MECN significantly reduced (P < 0.05) the body weight (33.38 ± 1.12 g) (F = 2.46, P = 0.04), visceral fat (1.62 ± 0.27) (F = 6.39, P = 0.0002), and muscle saturated fatty acid compositions (15.57%) (F = 16.24, P = 0.0001), especially in mice fed with 1500 mg/kg of MECN compared to the HFDC group. Conclusion: Therefore, MECN is a potentially useful natural supplement for alleviating obesity and obesity-mediated metabolic diseases.

Growth, biochemical, fatty acid composition, and mRNA levels of hepatic enzymes in genetically improved farmed tilapia (GIFT,Oreochromis niloticus) (Linnaeus, 1758) at different stocking densities

Investigated were the effects of stocking density on juvenile growth performance, serum biochemistry, fatty acid composition, and mRNA levels of enzymes involved in lipid metabolism in genetically improved farmed tilapia (GIFT), Oreochromis niloticus. Juvenile fish (n = 900) were distributed into 15 tanks at five initial stocking densities (75, 150, 225, 300, and 375 g/m3 per 800-L tank, represented as D1–D5, respectively). Temperature was maintained at 28 ± 0.3°C, and water flow rate into the tanks was about 8 L/min. The fish accepted floating pelleted feed (crude protein 28%, crude lipid 6%, and gross energy 149.2 KJ/g diet). The feed amount offered was 4%–8% of body weight. At the end of the 60-day experiment, the final stocking densities were 1,454.18, 2,010.60, 2,913.13, 3,819.73, and 4,380.80 g/m3, respectively. Growth and body mass coefficient of variation were significantly affected (p < .05). No differences in feed conversion rate or survival were found (p > .05). Muscle lipid contents decreased with stocking density from D1 to D5. Serum total protein and cholesterol levels were not affected by the stocking density but the D5 group produced the highest serum cortisol and lactate levels and the lowest glucose levels compared to those of the other groups. Lower muscle saturated fatty acid and n−3 polyunsaturated fatty acid contents were observed in the D4 group than in the other groups, whereas the reverse was found in the n−6 polyunsaturated fatty acid content. Hepatic glucose 6-phosphate dehydrogenase, fatty acid synthetase, hormone-sensitive triglyceride lipase, and lipoprotein lipase mRNA levels were significantly upregulated in response to a high density. These data suggest that the GIFT adapted to high-density conditions by altering the composition of muscle fatty acid and stimulating lipid metabolic enzymes. These mechanisms may help fish respond to high stocking density stress in intensive aquaculture systems.

Fatty Acid Profile and Oxidative Stress of Thigh Muscles in Chickens Fed The Ration Enriched in Lycopene, Selenium Compounds or Fish Oil

Abstract The aim of the study was to determine the influence of the addition for 6 weeks of 12 ppm lycopene (Lyc), 2% fish oil (FO) or 0.25 ppm Se as selenate (Sevi) or selenized yeast (SeY) to an isoenergetic and isonitrogenous ration containing sunflower oil as the source of energy on the profile of fatty acids (FA) and the oxidative stress in thigh muscles of female and male chickens. The ration with FO most efficiently increased the concentration of saturated fatty acids (SFA), atherogenic SFA and thrombogenic SFA as well as the concentration sum of all assayed FA in muscles of chickens. the rations with lyc, sevi or SeY revealed negligible and inconsistent impact on the concentration of individual SFA in muscles compared with the control. The ration with FO most efficiently increased the concentration of polyunsaturated FA (PUFA), especially n-3 long-chain PUFA and the sum of conjugated linoleic acid isomers in muscles. The ration with SeY most effectively increased the concentration of long-chain PUFA (LPUFA), especially n-6 LPUFA, in muscles of chickens. the Fo, lyc or sevi-fed chickens had a lower concentration of cholesterol in muscles than the control or SeY fed birds. Lyc added to the ration most efficiently stimulated the accumulation of α-tocopherol in muscles of chickens. The ration with Sevi most effectively stimulated the formation of malondialdehyde in muscles.

Fatty Acid Profiles and Stearoyl-CoA Desaturase Gene Expression in Longissimus dorsi Muscle of Growing Lambs Influenced by Addition of Tea Saponins and Soybean Oil.

This study was conducted to determine the effects of dietary addition of tea saponins (TS) and soybean oil (SO) on fatty acid profile and gene expression of stearoyl-CoA desaturase (SCD) in longissimus dorsi (LD) muscle of growing lambs. Thirty-two Huzhou lambs were assigned to four dietary treatments in a 2×2 factorial arrangement with main effects of TS (0 or 3 g/d) and SO (0 or 30 g/kg of diet DM). The diet without additives was considered as NTNS (no TS or SO). After a feeding trial for 60 d, four lambs of each treatment were slaughtered to collect the samples of LD muscle. Percentage of trans-11 vaccenic acid was enhanced (p<0.05) in muscle of lambs fed TS and SO. The proportion of total conjugated linoleic acid (CLA) was increased (p<0.05) by SO, but decreased (p<0.05) by TS in LD muscle. The percentage of total saturated fatty acids in muscle was decreased (p<0.05) by addition of TS and SO, while addition of SO increased (p<0.05) the percentage of total polyunsaturated fatty acids. The ratio of cis-9, trans-11 CLA to tran-11 vaccenic acid was decreased (p<0.05) by TS, but increased (p<0.05) by SO. The same effects were observed in SCD mRNA expression. From these results it is indicated that including TS and SO in the diet of growing lambs affect the fatty acid profiles of LD muscle and that the proportion of cis-9, trans-11 CLA in the muscle influenced by TS and SO may be related to the SCD gene expression.

Influence of dietary selenium level on the concentration of conjugated linoleic acid isomers, other fatty acids and amino acids in the liver and femoral muscles of rats

The purpose of the present study was to determine the influence of diets containing conjugated linoleic acid isomers (CLAmix) with or without low (&lt;sub&gt;L&lt;/sub&gt;Se) or high (&lt;sub&gt;H&lt;/sub&gt;Se) concentration of selenised yeast (SeY) on body weight gain (BWG), feed conversion efficiency (FCE), and concentrations of CLA isomers and other fatty acids (FA) in the liver and femoral muscle of rats. The investigation was performed on 48 female rats (Wistar, Hsd Brl Han: WIST), aged 8 weeks with an initial body weight of 195.7 &amp;plusmn; 0.8 g. After one week of submaintenance feeding, for 6 weeks the rats were fed ad libitum the Labofeed H diet supplemented with 1.5% CLAmix with or without low (0.2 &amp;mu;g Se/g diet) or high (0.5 &amp;mu;g Se/g diet) concentration of Se as SeY. The diet enriched with &lt;sub&gt;L&lt;/sub&gt;Se or &lt;sub&gt;H&lt;/sub&gt;Se elevated the BWG of rats compared with the control group, while the &lt;sub&gt;L&lt;/sub&gt;Se diet resulted in the most efficient increase in BWG. The diet containing CLAmix, irrespective of the presence of SeY, stimulated the accumulation of Se in the liver and muscles in comparison with the diet enriched with SeY. The addition of SeY to the diet enriched with CLAmix stimulated the accumulation of cis9trans11 (c9t11), t10c12 and cc isomers of CLA in the liver. The diet containing CLAmix and LSe most efficiently increased the concentration of these CLA isomers in muscles. The diets enriched with SeY increased the concentration of essential, endogenous and total amino acids (AA) in the liver, whereas the diets enriched with SeY or CLAmix reduced the concentration of these AA in muscles. The diets enriched with CLAmix and/or SeY decreased the &amp;Delta;9-desaturase index in the liver and muscles compared with the control group. These diets increased &amp;Delta;4-, &amp;Delta;5- and &amp;Delta;6-desaturase indexes in muscles, but significantly reduced the elongase index compared with the control group. Our study shows that dietary CLAmix increased the concentration of C14:0, C18:0 and the sum of saturated FA (SFA) in the liver, whereas the diets enriched with SeY, irrespective of the presence of CLAmix, slightly reduced the concentration of C14:0, C18:0, and SFA in muscles compared with the control group. The diets containing SeY and/or CLAmix increased the accumulation of arachidonic acid (ArA), linolenic acid (&amp;alpha;LNA) and c4c7c10c13c16c19C22:6 in the liver compared with the control rats. Negative effects of dietary SeY and/or CLAmix on the accumulation of &amp;alpha;LNA, c5c8c11c14c17C20:5, c7c10c13c16c19C22:5, c4c7c10c13c16c19C22:6, linoleic acid, ArA and c8c11c14C20:3 in muscles were found out. The CLAmix diet increased the &amp;Delta;4-, &amp;Delta;5-desaturase and elongase indexes in the liver. It also increased the &amp;Delta;4-, &amp;Delta;5- and &amp;Delta;6-desaturase indexes in muscles, but significantly reduced the elongase index compared with the control group. The finding that the diet with CLAmix and &lt;sub&gt;H&lt;/sub&gt;Se fed to rats decreased total FA and most efficiently increased the content of Se and essential AA in muscles is valuable information for nutritionists carrying out research on farm animals to improve the nutritive value of food from the aspect of human health.

Non‐gelatinized starch influences the deposition of n‐3 fatty acids in the muscle of a tropical freshwater fish, Labeo rohita

A 60-day feeding trial was conducted to study the influence of gelatinized (G) to non-gelatinized (NG) starch ratio in the diet on fatty acids profiles and oxidative status in Labeo rohita fingerlings. Two hundred and thirty-four fingerlings (average weight: 2.53 g) were distributed in six treatment groups with each of three replicates. Six semi-purified diets either containing NG and/or G corn starch (42.43%) viz., T(1) (100% NG and 0% G starch), T(2) (80% NG and 20% G starch), T(3) (60% NG and 40% G starch), T(4) (40% NG and 60% G starch), T(5) (20% NG and 80% G starch) and T(6) (0% NG and 100% G starch) was fed to respective groups. Catalase, superoxide dismutase and malic enzyme activities decreased linearly with the increasing level of G starch, whereas reverse trend was found for glucose-6-phosphate dehydrogenase. Total saturated fatty acids in muscle increased with the increasing level of G starch in the diet. Total n-3 fatty acids decreased linearly with the increasing level of G starch in the diet. Among the n-3 fatty acids, linolenic acids content was more in NG starch fed group. Similarly, eicosapentaenoic acid contents gradually decreased with increasing level of G starch content. The n-6/n-3 ratio was higher in G starch fed group. This suggests that dietary starch type may be manipulated for quality improvement of fish flesh.

Effects of Tasco (a seaweed extract) and heat stress on N metabolism and meat fatty acids in wether lambs fed hays containing endophyte-infected fescue

Wether lambs ( n = 27, average BW = 40 kg) were used to test response to forage treated with Tasco-Forage (an extract of the brown kelp Ascophyllum nodosum) prior to conserving, or to direct feeding of the extract (Tasco-EX). Hays made from endophyte ( Neoyphodium coenophialum)-infested tall fescue ( Festuca arundinacea)-based pasture received 0 or 3 kg of Tasco/ha prior to harvest. Lambs, blocked by weight, were randomly allotted to three diets: (1) control hay, (2) treated hay, and (3) #1 + Tasco-EX fed at 1% of the diet. Hays were low in CP (<7%) so all lambs were fed soybean meal (12% of the diet) in addition to trace mineralized salt. Diets were fed at 1.5% BW to prevent refusals. Total collections (7 d) were made during periods without or with applied heat stress. After each period, rumen contents were obtained to determine pH, NH 3 and VFA. Lambs were sacrificed post-trial. A subset was used to evaluate sensory traits and muscle fatty acids. Lambs were in negative N balance during the study and Tasco treatments did not affect N metabolism. Fecal N tended ( P < 0.10) to increase with short duration heat stress causing a concomitant decrease ( P < 0.05) in apparent N digestibility (58.6 versus 56.1%; S.E. = 0.7). Urinary N loss decreased ( P < 0.001) with heat stress (8.0 versus 5.9 g/d; S.E. = 0.2), resulting in increased ( P < 0.001) N retention (−2.1 versus −0.3 g/d; S.E. = 0.2). Apparent OM digestibility was not affected by heat stress but was greater ( P < 0.05) for lambs fed Tasco-EX treatment than those fed treated hay. Treatment diets decreased ( P < 0.05) ruminal butyrate. Heat stress increased ( P < 0.05) acetate and total VFA and decreased ( P < 0.01) ruminal pH. A tendency ( P < 0.11) of increased 14:1ω5, decreased ( P < 0.05) 18:0 and total saturated fatty acids in muscle was observed with Tasco diets. Meat sensory characteristics were not affected by treatment. Tasco may alter some aspects of rumen or lipid metabolism but has no effect on N metabolism or meat sensory characteristics of sheep fed restricted, low-quality diets.

The effect of linseed oil and selenium on the content of fatty acids and some elements in the liver and selected tissues of sheep

The effect of selenium (as Na 2 SeO 4 ) and linseed oil on the mass of M. biceps femoris and liver of sheep, as well as on the fatty acid composition and Se, Zn, Fe, Mg and Ca levels of M. biceps femoris, liver and intermuscular fat was investigated. Twenty male lambs of body weight of 25±2 kg were divided into four treatment groups and fed a control diet or experimental diets enriched in 5% linseed oil (LO), 2 ppm Se (SE) or combined addition of 5% LO and 2 ppm Se (LOSE). All experimental diets statistically or numerically decreased the concentration of cis-9C18:1 and saturated fatty acids in muscles and liver, while feeding SE usually significantly or numerically decreased the sum of all assayed fatty acids in muscles and liver. Diets enriched in Se (SE and LOSE) significantly increased the Se concentration in these samples, as well as numerically increased the Zn content in muscles and liver. LO and LOSE significantly or numerically decreased Δ9 desaturation in muscles, liver and fat. LOSE numerically decreased the content of conjugated linoleic acid isomers in all assayed samples.

Fatty acid profiles and sensory and carcass traits of tissues from steers and swine fed an elevated monounsaturated fat diet.

Twelve Angus X Hereford steers were assigned to either a control high-energy diet or a test diet consisting of 20% rapeseed at the expense of 20% corn. Twelve pigs were allotted to a control diet and two test diets containing either 10 or 20% canola oil (CO). Both CO and oil in the rapeseed contained 60 to 64% oleic acid. Cattle fed rapeseed exhibited little effect from the diet due to apparent indigestibility of the rapeseed. Total saturated fatty acids decreased from 40% in adipose tissue of the control pigs to 15% in the 20% CO-fed pigs. The ratio of monounsaturated to saturated fatty acids (M/S) increased from 1.19 in adipose tissue from control pigs to 3.63 with the addition of 20% CO to the diet. In muscle, the M/S ratio increased from 1.21 in control pigs to 2.46 in the 20% CO treatment group. The percentage of the saturated fatty acids in muscle decreased from 42% in the control to 23% in the 20% CO treatment. Significant increases in "oiliness" and decreases in fat firmness were observed when increasing levels of canola oil were fed. Sensory traits, cooking loss and shear-force values of pork chops were similar among treatment groups. In conclusion, monounsaturated fatty acid content can be elevated substantially in pork without adversely influencing the quality of the meat, thus producing a product perceived to be more healthful by the consumer.