Embryonic fatty acid metabolism in diabetic pregnancy: the difference between embryoblasts and trophoblasts.

During the first days of development the preimplantation embryo is supplied with nutrients from the surrounding milieu. Maternal diabetes mellitus affects the uterine microenvironment, leading to a metabolic adaptation processes in the embryo. We analysed embryonic fatty acid (FA) profiles and expression of processing genes in rabbit blastocysts, separately in embryoblasts (EBs) and trophoblasts (TBs), to determine the potential consequences of maternal diabetes mellitus on intracellular FA metabolism. Insulin-dependent diabetes was induced by alloxan in female rabbits. On Day 6 post coitum, FA profiles in blastocysts (EB, TB and blastocoel fluid) and maternal blood were analysed by gas chromatography. The expression levels of molecules involved in FA elongation (fatty acid elongases, ELOVLs) and desaturation (fatty acid desaturases, FADSs) were measured in EB and TB. Maternal diabetes mellitus influenced the FA profile in maternal plasma and blastocysts. Independent from metabolic changes, rabbit blastocysts contained a higher level of saturated fatty acids (SFAs) and a lower level of polyunsaturated fatty acids (PUFAs) compared to the FA profile of the maternal plasma. Furthermore, the FA profile was altered in the EB and TB, differently. While SFAs (palmitic and stearic acid) were elevated in EB of diabetic rabbits, PUFAs, such as docosahexaenoic acid, were decreased. In contrast, in the TB, lower levels of SFAs and higher levels of oleic acid were observed. EB and TB specific alterations in gene expression were found for ELOVLs and FADSs, key enzymes for FA elongation and desaturation. In conclusion, maternal diabetes mellitus alters embryonic FA metabolism differently in EB and TB, indicating a lineage-specific metabolic adaptive response.

On the relevance of technical variation due to building pools in microarray experiments.

BACKGROUND: Pooled samples are frequently used in experiments measuring gene expression. In this method, RNA from different individuals sharing the same experimental conditions and explanatory variables is blended and their concentrations are jointly measured. As a matter of principle, individuals are represented in equal shares in each pool. However, some degree of disproportionality may arise from the limits of technical precision. As a consequence a special kind of technical error occurs, which can be modelled by a respective variance component. Previously published theory - allowing for variable pool sizes - has been applied to four microarray gene expression data sets from different species in order to assess the practical relevance of this type of technical error in terms of significance and size of this variance component. RESULTS: The number of transcripts with a significant variance component due to imperfect blending was found to be 4329 (23 %) in mouse data and 7093 (49 %) in honey bees, but only 6 in rats and none whatsoever in human data. These results correspond to a false discovery rate of 5 % in each data set. The number of transcripts found to be differentially expressed between treatments was always higher when the blending error variance was neglected. Simulations clearly indicated overly-optimistic (anti-conservative) test results in terms of false discovery rates whenever this source of variability was not represented in the model. CONCLUSIONS: Imperfect equality of shares when blending RNA from different individuals into joint pools of variable size is a source of technical variation with relevance for experimental design, practice at the laboratory bench and data analysis. Its potentially adverse effects, incorrect identification of differentially expressed transcripts and overly-optimistic significance tests, can be fully avoided, however, by the sound application of recently established theory and models for data analysis.

Higher body fatness in intrauterine growth retarded juvenile pigs is associated with lower fat and higher carbohydrate oxidation during ad libitum and restricted feeding.

PURPOSE: A thrifty energy metabolism has been suggested in intrauterine growth restricted (IUGR) offspring. We characterized energy metabolism and substrate oxidation patterns in IUGR pigs in response to food restriction (FR) and refeeding (RFD). METHODS: Female pigs with low (L; 1.1 kg; n = 20) or normal birth weight (N; 1.5 kg; n = 24) were fed ad libitum after weaning. Half of L and N pigs were food restricted (R; LR, NR) from days 80 to 100 (57% of ad libitum) and refeed from days 101 to 131, while the remaining pigs were fed ad libitum (control, C). Using indirect calorimetry, carbohydrate and fat oxidation (COX, FOX), energy expenditure (EE) and balance (EB), resting metabolic rate (RMR) [all related to kg body weight(0.62) (BW)] and RQ were determined at 4 days before (day 76) and after (day 83) beginning of FR, 4 days before (day 97) and after (day 104) end of FR and 25 days after beginning of RFD (day 125). Body fat and muscle weights were determined at day 131. RESULTS: In spite of higher relative food intake (FI), BW was lower in L pigs. In L pigs, physical activity was lower at age 76 and 83 days compared to N pigs. IUGR did not affect EE or RMR, but resulted in higher COX and lower FOX, causing greater and earlier onset of fat deposition. During FR, EE and RMR of R pigs dropped below that of C pigs, and BW gain was delayed by 30% irrespective of birth weight. In response to FR, COX decreased and FOX increased. During FR, in LR pigs FOX was ~50% of that in NR pigs. After 4 days, but not 25 days of RFD, EB and fat synthesis were higher in pigs previously subjected to FR, indicating early catch-up fat. In R pigs, BW and the abdominal fat proportion were lower at 131 days. CONCLUSIONS: Differences in food intake and substrate oxidation pattern, but not in EE and RMR, between L and N pigs were reflected in higher body fat proportions but lower body and muscle weights in L pigs. Refeeding following FR was initially associated with increased FI, a more positive EB and a more intense stimulation of fat synthesis which did not persist after 25 days of refeeding.

Dietary n-3 PUFA affect lipid metabolism and tissue function-related genes in bovine muscle.

Gene expression profiles of bovine longissimus muscle as affected by dietary n-3 v. n-6 fatty acid (FA) intervention were analysed by microarray pre-screening of >3000 muscle biology/meat quality-related genes as well as subsequent quantitative RT-PCR gene expression validation of genes encoding lipogenesis-related transcription factors (CCAAT/enhancer-binding protein ß, sterol regulatory element-binding transcription factor 1), key-lipogenic enzymes (acetyl-CoA carboxylase α (ACACA), fatty acid synthase (FASN), stearoyl-CoA desaturase (SCD)), lipid storage-associated proteins (adipose differentiation-related protein (ADFP)) and muscle biology-related proteins (cholinergic receptor, nicotinic, α1, farnesyl diphosphate farnesyl transferase 1, sema domain 3C (SEMA3C)). Down-regulation of ACACA (P = 0·00), FASN (P = 0·09) and SCD (P = 0·02) gene expression upon an n-3 FA intervention directly corresponded to reduced SFA, MUFA and total FA concentrations in longissimus muscle, whereas changes in ADFP (P = 0·00) and SEMA3C (P = 0·05) gene expression indicated improved muscle function via enhanced energy metabolism, vasculogenesis, innervation and mediator synthesis. The present study highlights the significance of dietary n-3 FA intervention on muscle development, maintenance and function, which are relevant for meat quality tailoring of bovine tissues and modulating animal production-relevant physiological processes.

Dietary fatty acid intervention of lactating cows simultaneously affects lipid profiles of meat and milk.

BACKGROUND: The present study investigated tissue-specific responses of muscle and mammary gland to a 10 week intervention of German Holstein cows (n = 18) with three different dietary fat supplements (saturated fat; linseed oil or sunflower oil plus docosahexaenoic acid-rich algae) by analysing fatty acid profiles and quality parameters of meat and milk. RESULTS: Plant oil/algae intervention affected neither fat content nor quality parameters of meat but decreased fat content and saturated fatty acid amounts of milk. Linseed oil/algae intervention caused significantly higher concentrations of C18:3n-3 (meat, 1.0 g per 100 g; milk, 1.2 g per 100 g) and C22:6n-3 (meat, 0.3 g per 100 g; milk, 0.14 g per 100 g). Sunflower oil/algae intervention increased n-6 fatty acid contents in milk (4.0 g per 100 g) but not in meat. Elevated amounts of C18:1trans isomers and C18:1trans-11 were found in meat and especially in milk of plant oil/algae-fed cows. C18:1cis-9 amounts were found to be increased in milk but decreased in meat after plant oil/algae intervention. CONCLUSION: The present study demonstrated that dietary fatty acid manipulation substantially shifted the fatty acid profiles of milk and to a lesser extent of meat, whereas meat quality traits were not affected. Indications of tissue-specific responses of mammary gland and muscle were identified.

Comparison of different methylation methods for the analysis of conjugated linoleic acid isomers by silver ion HPLC in beef lipids.

Four different methods for the methylation of conjugated linoleic acid isomers (CLA) in ruminant lipids were compared by silver ion (Ag+) HPLC. The combination of base-catalyzed methods followed by an acid-catalyzed method with BF3/MeOH was tested under different temperatures (room temperature and at 60 degrees C), along with based-catalyzed methylation with NaOCH3 and methylation with BF3/MeOH after saponification with NaOH. The comparison among these four methods was done on muscle and adipose tissue samples from bulls. The repeatability theta of the combined base- and acid-catalyzed methylation (NaOCH3/BF3) at ambient temperature for 20 min and at 60 degrees C for 10 min was most suitable for the quantitative Ag+-HPLC analysis of CLA isomers. At 60 degrees C the combined methods supplied the highest concentrations of most CLA isomers. The base-catalyzed methylation and the saponification followed by BF3/MeOH methylation for 5 min generated significantly lower concentrations for most CLA isomers compared to the combined methods.

Diet alters the fatty acid composition of individual phospholipid classes in beef muscle.

The objective of this study was to investigate the effect of diet on the distribution of phospholipid classes and fatty acid profiles of individual phospholipid classes in longissimus muscle of beef. An experiment was established to examine the effect of pasture-based versus concentrate diet offered to two different breeds (German Holstein and German Simmental bulls) to enhance the content of beneficial fatty acids in beef and improve the meat quality for the consumer. High-performance thin-layer chromatography was utilized to separate the phospholipid classes. The fatty acid composition of the individual phospholipid classes was determined by gas chromatography. The main phospholipid classes in the muscle were phosphatidylethanolamine and phosphatidylcholine, representing approximately 60% of the total phospholipids, followed by phosphatidylinositol ranging between 11.8 and 14.8%. The results have shown that the fatty acid profiles in the detected seven phospholipid classes can be affected by different feeding systems. Pasture-based feeding resulted in an enrichment of total and individual n-3 fatty acids in all phospholipid classes of muscle lipids of bulls compared with those fed on concentrate. In contrast, pasture-based diet significantly decreased the proportion of total and individual n-6 fatty acids in phospholipid classes, except in the sphingomyelin fraction. The total saturated fatty acid proportions in the phospholipid classes were different and ranged between 4.5% in the cardiolipin fraction and 50.5% in the sphingomyelin fraction of muscle lipids of bulls. Furthermore, the diet effects on the saturated fatty acid proportion in the different phospholipid classes differ widely. The results have shown that the C18:1 trans and CLA profiles in the detected seven phospholipid classes can be affected by different feeding systems.

Vaccenic acid and cis-9,trans-11 CLA in the rumen and different tissues of pasture- and concentrate-fed beef cattle.

The objective of present study was the comparison of trans-11 18:1 (VA) and cis-9,trans-11 CLA concentrations in the rumen and different tissues in beef cattle, and to examine the diet and breed effects on the compound concentration and deposition. Sixty-four German Holstein and German Simmental bulls were randomly assigned to two dietary treatments, based on concentrate or pasture. The concentration of cis-9,trans-11 CLA and VA in rumen, duodenal digesta and different tissues was determined by gas chromatography. The results showed that pasture relative to concentrate feeding significantly increased the concentration of VA in duodenal digesta, plasma and erythrocyte phospholipids. Pasture-based feeding resulted in a significant enrichment of cis-9,trans-11 CLA in plasma lipids and erythrocyte phospholipids, but not in rumen and duodenal digesta, compared to concentrate-fed diet. Diet did not affect the cis-9,trans-11 CLA concentrations (mg/100 g fresh tissue) in semitendinosus muscle and subcutaneous fat. There was a breed effect on the deposition of cis-9,trans-11 CLA in longissimus muscle with lower concentration in pasture-fed German Simmental bulls compared to concentrate-fed bulls. However, pasture feeding significantly increased both, the VA and cis-9,trans-11 CLA concentrations in liver and heart tissues. Both diet and breed effects on Delta(9)-desaturase index was observed in muscle and subcutaneous fat tissues. There was a linear relationship between the concentration of VA and cis-9,trans-11 CLA and the coefficients of determination (R (2)) varied between 0.29 and 0.87 from rumen to the different tissues.

Effects of dietary supplementation of vitamins D(3) and E on quality characteristics of pigs and longissimus muscle antioxidative capacity.

The effects of addition of vitamin D(3) and vitamin E to pig diets on blood plasma calcium concentration, meat quality (longissimus muscle) and antioxidative capacity were investigated. Two treatments consisted of supplementation with vitamin D(3) (500,000IU/d) for 5 days separately (group D) and a combination of vitamin E (500mg α-tocopheryl acetate/kg diet) for 30 days and vitamin D(3) (500,000IU/d) for 5 days (group D+E) to growing-finishing pigs before slaughter. Pigs fed with vitamin D(3) had higher (P<0.01) plasma calcium concentration compared with control pigs. Dietary supplementation of vitamin E significantly (P<0.05) increased the concentration of α-tocopherol in meat (longissimus muscle). Vitamin D(3) supplementation resulted in higher (P=0.07) a(∗) values of loin chops at 5 days of storage. Vitamin D(3) and vitamin E supplementation did not affect other meat quality characteristics or tenderness (quantified by Warner-Bratzler shear force). Antioxidative capacity (measured as MDA production after incubation of longissimus muscle homogenates with Fe(2+)/ascorbate) was improved by vitamin E and partly by vitamin D(3) supplementation.

Analysis of fatty aldehyde composition, including 12-methyltridecanal, in plasmalogens from longissimus muscle of concentrate- and pasture-fed bulls.

In a large study, 64 German Holstein and German Simmental bulls were randomly allocated to either an indoor concentrate system or periods of pasture feeding followed by a finishing period on a concentrate containing linseed to enhance the contents of beneficial fatty acids in beef. This paper reports the diet effects on the concentration of 12-methyltridecanal (12-MT) and further fatty aldehydes released from plasmalogens in the phospholipids of longissimus muscle of the bulls. Because of the trace level of the important odorant 12-MT in beef, the determination of fatty aldehydes in phospholipids was done by acidic hydrolysis and the reaction of the aldehydes with 2,4-DNPH followed by high-pressure liquid chromatography (HPLC) analysis. The diet affected the 12-MT concentrations in the muscle phospholipids of both breeds. Pasture feeding significantly increased the 12-MT concentrations up to 350 microg/100 g fresh muscle in the muscle phospholipids of German Holstein and German Simmental bulls as compared with the concentrate-fed bulls. Furthermore, pasture feeding resulted in a significant increase of n-octadecanal in the muscle phospholipids of both breeds up to 39.5 mg/100 g fresh muscle. The concentration of n-hexadecanal was not affected by the diet. Pasture feeding as compared to concentrate feeding significantly decreased the concentration of n-octadec-9-enal in the muscle phospholipids. Summarizing, pasture feeding increased the 12-MT concentration, which can be associated with meat of more intensive aroma and better taste.

Effect of pasture vs. concentrate diet on CLA isomer distribution in different tissue lipids of beef cattle.

This study examined the effects of feeding pasture vs. concentrate on the distribution of CLA isomers in the lipids of longissimus and semitendinosus muscle, liver and heart muscle, and subcutaneous fat in beef bulls. Sixty-four German Holstein and German Simmental bulls were randomly allocated to either an indoor concentrate system or periods of pasture feeding followed by a finishing period on a concentrate containing linseed to enhance their beef content of n-3 PUFA and CLA. The concentrations of CLA isomers in the different tissues were determined by GC and silver ion HPLC. The diet affected the distribution of individual CLA isomers in the lipids of the different tissues. The concentration (mg/100 g fresh tissue) of the most prominent isomer, cis-9,trans-11 18:2, was increased up to 1.5 times in liver and heart tissue of bulls fed on pasture as compared with concentrate. However, no diet effect was observed for cis-9,trans-11 18:2 in the lipids of longissimus muscle and subcutaneous fat. In all tissues, the second-most abundant CLA isomer in concentrate-fed bulls was trans-7,cis-9 18:2. In contrast, trans-11,cis-13 18:2 was the second-most abundant CLA isomer in all investigated tissue lipids of pasture-fed bulls. The concentration of the trans-11,cis-13 18:2 isomer was up to 15 times higher in tissues of pasture-fed bulls as compared with concentrate-fed animals. Furthermore, diet affected the concentrations of the CLA trans,trans 18:2 isomers. Pasture feeding significantly increased the concentrations of some trans,trans 18:2 isomers as compared with concentrate, predominantly trans-12,trans-14 18:2 and trans-11,trans-13 18:2. Overall, pasture feeding resulted in significantly increased concentrations of the sum of CLA isomers in the lipids of longissimus muscle, subcutaneous fat, heart and liver muscle of German Holstein and German Simmental bulls, but not in semitendinosus muscle.

Effects of dietary olive and linseed oil on lipid composition, meat quality, sensory characteristics and muscle structure in pigs.

The aim of this study was to alter the fatty acid composition of porcine tissue by accumulating essential fatty acids without adversely affecting carcass composition, muscle structure or meat eating quality. A total of 13 female and 12 castrated Pietrain×German Landrace pigs were fed a basal concentrate diet supplemented with 5% olive oil or 5% linseed oil during the growing-finishing period. Carcass composition and meat quality were not affected by the diet. Feeding linseed oil to pigs significantly increased the relative content of linolenic acid and long chain n-3 fatty acids in lipids of muscle, backfat and heart at the expense of arachidonic acid. Oleic acid was accumulated in muscle, backfat and heart lipids by feeding olive oil. The overall flavour of combined meat/backfat samples from castrates was negatively influenced by linseed oil supplementation compared to supplementation with olive oil. The oxidative stability of muscle lipids was lower in linseed oil-fed pigs compared to olive oil fed pigs. The greater cross section areas of the longissimus muscle of females were caused by an increased diameter of red, intermediate and white fibres.

Effect of diet on the deposition of n-3 fatty acids, conjugated linoleic and C18:1trans fatty acid isomers in muscle lipids of German Holstein bulls.

This study examined the effects of feeding diets rich in either n-3 or n-6 polyunsaturated fatty acids (PUFA) on the fatty acid composition of longissimus muscle in beef bulls. Thirty-three German Holstein bulls were randomly allocated to either an indoor concentrate system or periods of pasture feeding (160 days) followed by a finishing period on a concentrate containing linseed to enhance the contents of n-3 PUFA and conjugated linoleic acids (CLA) in beef muscle. The relative proportion and concentration (mg/100 g fresh muscle) of n-3 fatty acids in the phospholipid and triglyceride fractions were significantly increased (p < or = 0.05) in muscle lipids of pasture-fed bulls. The pasture feeding affected the distribution of individual CLA isomers in the muscle lipids. The proportion of the most prominent isomer, CLA cis-9,trans-11, was decreased from 73.5 to 65.0% of total CLA in bulls fed on concentrate as compared to pasture. The second most abundant CLA isomers were CLA trans-7,cis-9 and CLA trans-11,cis-13 in bulls fed on concentrate and pasture, respectively. Diet had no effect on the concentration of C18:1 trans-11. In contrast, the concentration of the C18:1 trans-13/14, trans-15, and trans-16 isomers in the muscle lipids was up to two times higher in pasture-fed as compared to concentrate-fed bulls. Pasture feeding enhanced the concentration of n-3 fatty acids, but the diet had no effect on the concentration of CLA cis-9,trans-11.

Impact of dietary protein level and source of polyunsaturated fatty acids on lipid metabolism-related protein expression and fatty acid concentrations in porcine tissues.

The study assessed the effects of reduced protein (RPD) vs high protein diet (HPD) in combination with n-3/n-6 PUFA-containing plant oils [linseed oil (LO)/sunflower seed oil (SO)] supplementation on lipid metabolism-related protein expression and fatty acid concentrations in porcine tissues. Forty male Landrace pigs (castrates) were allocated into four groups fed diets different in dietary protein and PUFA level and one control group. SCD-1 protein expression in pig muscle, back fat, and liver was not affected by diet. The protein expression of precursor (pSREBP-1c) and active nuclear form of SREBP-1c (mSREBP-1c) in muscle and back fat was affected by diet, however not in liver of pigs. In contrast, the expression of ACC and FAS expression was significantly affected by diet only in the liver. The fatty acid concentrations in muscle, liver, and back fat resulted in higher n-3 PUFA concentrations of LO groups compared to the SO groups.

Fatty acid profiles and adipogenic gene expression of various fat depots in Japanese Black and Holstein steers.

Objective of the study was to assess the breed effect on fatty acid (FA) composition of different adipose tissues and on mRNA expression of genes involved in adipogenesis and fat metabolism. Japanese Black (JB) and Holstein (HS) steers were kept under equivalent conditions with high energy intake resulting in large differences in intramuscular fat (IMF) accumulation in longissimus muscle (LM). The relative FA composition of muscle, intermuscular fat, visceral fat, and perirenal fat was comparable between JB and HS steers. Circulating fatty acids were also similar in both breeds. Most relevant breed effects were identified in IMF, underlining the uniqueness of this adipose tissue site. JB steers had more monounsaturated FA and less saturated FA. Perilipin 1 and adipose differentiation-related protein (ADFP) mRNA levels were higher in IMF of JB. The results suggest advanced maturity of IMF cells in JB and altered local conditions in muscle influencing IMF accumulation and composition.

How selected tissues of lactating holstein cows respond to dietary polyunsaturated fatty acid supplementation.

The effect of a 10-week supplementation with polyunsaturated fatty acids [via sunflower oil/DHA-rich algae (SUNA) or linseed oil/DHA-rich algae (LINA) enriched diets] versus saturated fatty acids (SAT) of lactating German Holstein dairy cows in mid-lactation on expression patterns of lipid metabolism-associated genes and gene products in hepatic, longissimus muscle and subcutaneous/perirenal/omental adipose tissue was assessed. Most pronounced transcriptomic responses to dietary PUFA were obtained in hepatic [down-regulated ACACA (FC = 0.83, SUNA; FC = 0.86, LINA), FADS1 (FC = 0.60, SUNA; FC = 0.72, LINA), FADS2 (FC = 0.64, SUNA; FC = 0.79, LINA), FASN (FC = 0.64, SUNA; FC = 0.72, LINA), SCD (FC = 0.37, SUNA; FC = 0.47, LINA) and SREBF1 (FC = 0.79, SUNA, LINA) expression] and omental adipose [up-regulated ACACA (FC = 1.58, SUNA; FC = 1.22, LINA), ADFP (FC = 1.33, SUNA; FC = 1.32, LINA), CEBPA (FC = 1.75, SUNA; FC = 1.40, LINA), FASN (FC = 1.57, SUNA; FC = 1.21, LINA), LPL (FC = 1.50, SUNA; FC = 1.20, LINA), PPARG (FC = 1.36, SUNA; FC = 1.12, LINA), SCD (FC = 1.41, SUNA; FC = 1.17, LINA) and SREBF1 (FC = 1.56, SUNA; FC = 1.18, LINA) expression] tissue. Interestingly, gene/gene product associations were comparatively low in hepatic and omental adipose tissue compared with longissimus muscle, perirenal adipose and subcutaneous adipose tissue, indicating matches only in regard to minor concentrations of SCD product 18:1c9, FADS1 product 20:4n-6 and FADS2 product 18:3n-6 in hepatic tissue, and higher concentrations of ACACA and FASN gene products 12:0 and 14:0 and SCD product 18:2c9,t11 in omental adipose tissue. Whereas all analyzed tissues accumulated dietary PUFA and their ruminally generated biohydrogenation products, tissue-divergent preferences for certain fatty acids were identified. This descriptive study reports tissue-divergent effects of dietary PUFA and outlines the significance of a PUFA intervention with regard to dairy cows' nutritional management.

High-fat diets rich in ω-3 or ω-6 polyunsaturated fatty acids have distinct effects on lipid profiles and lipid peroxidation in mice selected for either high body weight or leanness.

OBJECTIVE: The aim of the study is to determine the response of muscle lipid peroxidation and the fatty-acid profile of three groups of mice-high body weight (DU6) obesity-prone mice, high treadmill performance (DUhTP) lean mice, and unselected control mice (DUK) fed high-fat diets (HFDs) rich in ω-3 or ω-6 polyunsaturated fatty acids (PUFA). METHODS: The isocaloric HFDs were enriched with either ω-3 PUFA (27% fish oil, ω-3 HFD) or ω-6 PUFA (27% sunflower oil, ω-6 HFD), and the control group was fed standard chow (7.2% fat). Statistical calculations were done with procedure GLM of SAS. RESULTS: As expected, the ω-3 and ω-6 PUFA-rich HFDs showed significant effects on fatty-acid concentrations of skeletal muscle in all three lines of mice compared with the standard chow. The investigations of muscle lipid peroxidation revealed that the ω-3 PUFA-rich HFD caused the highest lipid peroxidation values in muscle of lean DUhTP mice and unselected control DUK mice. However, lower lipid peroxidation levels were observed in the obesity-prone DU6 mice. In contrast, the ω-6 PUFA-rich HFD did not influence lipid peroxidation in muscle of any of the different lines of mice. The present study suggests that a higher overall antioxidant capacity in the muscle tissue of obesity-prone DU6 mice may lead to lower levels of reactive oxygen species formation by ω-3 PUFA-rich HFDs in comparison with lean DUhTP mice. CONCLUSION: These studies raise the possibility that obesity per se may be protective against oxidative damage when high ω-3 PUFA diets are used.

Dietary PUFA Intervention Affects Fatty Acid- and Micronutrient Profiles of Beef and Related Beef Products.

The study investigated the dietary impact of 18:3n-3 vs. 18:2n-6 on fatty acid- and micronutrient concentration of beef muscle and the extent of diet- and processing-induced changes of lipid- and micronutrient concentrations of beef products made thereof (German Corned beef (GCB), tea sausage spread (TSS), scalded sausage (SS)). Beef and beef products were obtained from German Holstein bulls which either received a control diet consisting of maize silage and concentrate with soybean meal (41%), or an experimental diet of grass silage and concentrate plus rapeseed cake (12%) and linseed oil (3%). The study revealed that upon an 18:3n-3 vs. 18:2n-6 intervention the amounts of 18:3n-3, EPA and Σn-3 LC-PUFA were significantly increased by 2.6, 2.3 and 1.7 fold, respectively. Experimental diet significantly increased ß-carotene contents, and the γ-tocopherol contents were decreased. During beef processing, n-3 PUFA from beef were found to be product-specifically transferred into the corresponding beef products. 18:3n-3 and Σn-3 LC-PUFA contents were found to be 1.4 and 1.5 times higher in GCB from grass silage- than maize silage-fed bulls. The trace element contents in GCB (iron, copper, zinc, selenium) were not affected by the diet; however γ-tocopherol contents were decreased by experimental diet. In conclusion, dietary n-3 PUFA were completely transferred into beef products unaffected by beef processing conditions.

Different dietary protein and PUFA interventions alter the fatty acid concentrations, but not the meat quality, of porcine muscle.

The present study investigated the effect of a reduced protein diet in combination with different vegetable oils (sunflower seed oil or linseed oil) on carcass traits, meat quality and fatty acid profile in porcine muscle. Forty male Landrace pigs were allocated into four experimental groups (each n = 8) and one control group (n = 8) at a live weight of approximately 60 kg. The pigs were fed ad libitum from 60 kg to 100 kg live weight and restricted to 2.8 kg/day until they reached 120 kg. In contrast to other studies, the intramuscular fat content (IMF) did not increase in animals of groups fed a reduced protein diet and vegetable oils. The IMF ranged between 1.2% and 1.4%. The growth performance and meat quality of the longissimus muscle was not affected by the diet, but the average daily gain (ADG) and drip loss were affected. The muscle fatty acid concentrations were significantly affected by the diet, resulting in higher n-3 FA concentrations up to 113 mg/100 g muscle and lower n-6/n-3 PUFA ratio for pigs fed linseed oil-containing high- and reduced protein diets, compared to sunflower seed oil-containing diets.

Trans-18:1 and CLA isomers in rumen and duodenal digesta of bulls fed n-3 and n-6 PUFA-based diets.

The aim of the study was to investigate the effect of n-6 PUFA (maize silage/grass silage, soybean meal and soybean oil, control) and n-3 PUFA (grass silage, rapeseed cake and rapeseed oil, experiment) based diets on the occurrence of rumen- and duodenal digesta trans-C18:1 and CLA isomers of German Simmental bulls. The results based on rumen and duodenal digesta samples immediately taken from the bulls just after slaughter. The diet affected the occurrence of individual trans-C18:1 and CLA isomers in the rumen and duodenal digesta in different ways. The isomer trans-11,cis-13 CLA was detected as the most abundant isomer in the rumen of n-3 PUFA based diet fed bulls compared to n-6 PUFA based diet fed bulls. The trans-7,cis-9 CLA isomer was not detected in the rumen samples of bulls fed both diets, however abundant trans-7,cis-9 CLA was identified and quantified in the duodenum digesta. Both the concentration of the sum of trans-18:1 fatty acids and individual isomers in the rumen were not affected by the diet, except trans-16-18:1. The concentration of trans-16-18:1 was significantly decreased in the rumen of n-3 PUFA supplemented-fed bulls compared to n-6 PUFA supplemented-fed bulls.