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 profile of plasma, muscle and adipose tissues in Chilota lambs grazing on two different low quality pasture types in Chiloé Archipelago (Chile).

There is no information about the effect of different pasture types on tissue fatty acid profiles of a native rustic lamb breed of the Chiloe Archipelago, the Chilota. Eight Chilota lambs were grazed on a 'Calafatal' pasture (CP), a typical secondary succession of Chiloé Archipelago (Chile) and eight Chilota lambs were located to graze on naturalized pasture (NP) of Chiloé. Botanical, chemical and lipid composition of the two types of pastures and of different lamb tissues (muscle, subcutaneous - and tail adipose tissues) and plasma were performed. Both pasture types induced high n-3 polyunsaturated fatty acids (PUFA) and CLAcis-9,trans-11 proportions in Chilota meat. Thus, in muscle, Chilota lambs grazing CP showed higher sum PUFA, sum n-6 PUFA proportion and n-6/n-3 PUFA ratio compared with Chilota lambs grazing NP. In tail fats of Chilota lambs grazing CP significantly higher proportions of 18:3n-3, sum saturated fatty acids, sum PUFA, n-3 and n-6 PUFA were detected compared with Chilota lambs grazing NP. Feeding of different pasture types (CP vs. NP) caused significant differences in fatty acid composition of muscle and the two fat depots in Chilota lambs, but also point to tissue-specific responses of de novo synthesized fatty acid deposition in the tissues.

Enhancing the nutritional and health value of beef lipids and their relationship with meat quality.

This paper focuses on dietary approaches to control intramuscular fat deposition to increase beneficial omega-3 polyunsaturated fatty acids (PUFA) and conjugated linoleic acid content and reduce saturated fatty acids in beef. Beef lipid trans-fatty acids are considered, along with relationships between lipids in beef and colour shelf-life and sensory attributes. Ruminal lipolysis and biohydrogenation limit the ability to improve beef lipids. Feeding omega-3 rich forage increases linolenic acid and long-chain PUFA in beef lipids, an effect increased by ruminally-protecting lipids, but consequently may alter flavour characteristics and shelf-life. Antioxidants, particularly α-tocopherol, stabilise high concentrations of muscle PUFA. Currently, the concentration of long-chain omega-3 PUFA in beef from cattle fed non-ruminally-protected lipids falls below the limit considered by some authorities to be labelled a source of omega-3 PUFA. The mechanisms regulating fatty acid isomer distribution in bovine tissues remain unclear. Further enhancement of beef lipids requires greater understanding of ruminal biohydrogenation.

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.

Distribution of conjugated linoleic acid (CLA) isomers and other fatty acids in polar and neutral fractions of milk from cows fed different lipid supplements / Distribución de isómeros de ácido linoléico conjugado (CLA) y ácidos grasos en las fracciones neutra y polar de la leche de vacas alimentadas con diferentes suplementos lipídicos / Distribuição de isômeros do acido linoleico conjugado (CLA) e outros ácidos graxos nas frações polares e neutras no leite de vacas alimentadas com diferentes suplementos lipídicos

Background: milk fatty acid composition has become very important for consumers due to the positive relationship that has been found between some fatty acids and human health. In recent years, content and fatty acid composition in the different fractions of milk lipids has also become important due to reported potential technological and sensory implications. Objective: the aim of this study was to evaluate the effect of dietary supplementation with several lipid supplements on the proportion of neutral (triglycerides) and polar lipids (phospholipids) of milk fat, alterations of the fatty acid composition and Conjugated Linolenic Acid isomers (CLA) of total milk lipids. Methods: 18 first lactation German Holstein cows were assigned to three dietary treatments for 10 weeks as follows: Rumen-stable fractionated palm fat, linseed oil plus algae, and sunflower oil plus algae. Results: dietary polyunsaturated fat supplements increased the proportion of phospholipids and decreased triglycerides in milk fat compared to Rumen-stable fractionated palm fat. Long chain polyunsaturated fatty acids were preferentially deposited into phospholipids. Diet effect was more pronounced in triglycerides than in phospholipids. Plant oil/algae supplemented diets induced lower proportions of total saturated fatty acids and higher proportions of total unsaturated fatty acids in triglycerides. Conclusions: linseed oil plus algae feeding generated the best results in reference to fatty acids related to human health. Sunflower oil plus algae caused accumulation of CLAtrans-10,cis-12, CLAtrans-7,cis-9, CLAtrans-7,trans-9 and CLAtrans-10,trans-12 and decrease of CLAtrans-9,trans-11 in total milk fat, whereas linseed oil plus algae increased CLAtrans-12,trans-14, CLAtrans-11,trans-13, and CLAtrans-11,cis-13 deposition compared to rumen-stable fractionated palm fat.

Antecedentes: la composición de ácidos grasos de la leche ha tomado gran importancia para los consumidores a causa de la relación positiva que se ha encontrado entre algunos ácidos grasos y la salud humana. En los últimos años, el contenido y composición de ácidos grasos en las diferentes fracciones de los lípidos de la leche también ha tomado importancia debido a las posibles implicaciones tecnológicas y sensoriales que se han reportado. Objetivo: el objetivo del presente estudio fue evaluar los cambios en la proporción de lípidos neutros (triglicéridos) y lípidos polares (fosfolípidos) y alteraciones de la composición de ácidos grasos e isómeros del Ácido Linoléico Conjugado (CLA) del total de lípidos de la leche como resultado de la suplementación dietaria con diferentes suplementos lipídicos. Métodos: 18 vacas Holstein Alemán de primera lactancia fueron asignadas a tres tratamientos dietarios durante 10 semanas, así: grasa de palma fraccionada y estable al rumen, aceite de lino más alga, y aceite de girasol más alga. Resultados: la suplementación con ácidos grasos poliinsaturados incrementó la proporción de fosfolípidos y disminuyó la de triglicéridos en la grasa de la leche comparado con grasa de palma fraccionada y estable al rumen. Los ácidos grasos poliinsaturados de cadena larga fueron preferencialmente depositados en los fosfolípidos. El efecto de la dieta fue más pronunciado en los triglicéridos que en los fosfolípidos. Las dietas suplementadas con aceite vegetal y alga indujeron a menores proporciones de ácidos grasos saturados y mayores proporciones de ácidos grasos insaturados en los triglicéridos. Conclusiones: la suplementación con aceite de lino más alga generó los mejores resultados respecto a la composición de ácidos grasos relacionados con la salud humana. El aceite de girasol más alga causó una acumulación de isomeros CLAtrans-10,cis-12, CLAtrans-7,cis-9, CLAtrans- 7,trans-9 y CLAtrans-10,trans-12 y disminuyó CLAtrans-9,trans-11 en la grasa total de la leche mientras que el aceite de lino más alga incrementó CLAtrans-12,trans-14, CLAtrans-11,trans-13, y CLAtrans-11,cis-13 comparado con la grasa de palma fraccionada y estable al rumen.

Antecedentes: a composição de ácidos graxos do leite tem-se tornado muito importante para os consumidores devido à relação positiva encontrada entre alguns ácidos graxos e a saúde humana. Nos últimos anos, o conteúdo e composição dos ácidos graxos nas diferentes frações lipídicas no leite também se tornaram importantes devido às consequências tecnológicas e sensoriais que tem sido reportada recentemente. Objetivo: realizou-se um estudo para avaliar as mudanças na proporção de lipídios neutros (triglicerídeos) e polares (fosfolipídios) na gordura do leite e as alterações da composição dos ácidos graxos e os isômeros do Ácido Linoleico Conjugado (CLA) no total dos lipídeos do leite como resultado da suplementação na dieta com diferentes suplementos lipídeos. Métodos: 18 vacas Holandesas na Alemanha, todas de primeira lactação foram avaliadas em três tratamentos com regimes alimentares diferentes durante 10 semanas, assim: óleo de palma fracionada e estável no rúmen, óleo de linhaça mais algas e óleo de girassol mais algas. Resultados: a suplementação com ácidos graxos poli-insaturados incrementou a proporção de fosfolipídios e diminuiu a proporção de triglicerídeos na gordura do leite, comparado com o óleo de palma fracionada e estável no rúmen. Os ácidos graxos poliinsaturados de cadeia longa foram preferencialmente depositados nos fosfolipídios. O efeito da dieta foi mais pronunciado nos triglicerídeos que nos fosfolipídios. As dietas que foram suplementadas com óleo vegetal mais algas reduziram a proporção de ácidos graxos saturados, e aumentaram a proporção de ácidos graxos insaturados nos triglicerídeos. Conclusões: a suplementação com óleo de linhaça mais alga gerou os melhores resultados respeito à composição dos ácidos graxos relacionados com a saúde humana. O óleo de girassol mais alga causaram uma acumulação de CLAtrans-10, cis-12, CLAtrans-7, cis-9, CLAtrans-7, trans-9 e CLAtrans-10, trans-12 e diminuiu CLAtrans-9, trans-11 na gordura total do leite, enquanto que óleo de linhaça mais alga aumentou a deposição de CLAtrans-12, trans-14, CLAtrans-11, trans-13, e CLAtrans-11, cis-13, em comparação com o óleo de palma fracionada e estável no rúmen.

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.

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.

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.

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.

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.

Association of an ACSL1 gene variant with polyunsaturated fatty acids in bovine skeletal muscle.

BACKGROUND: The intramuscular fat deposition and the fatty acid profiles of beef affect meat quality. High proportions of unsaturated fatty acids are related to beef flavor and are beneficial for the nutritional value of meat. Moreover, a variety of clinical and epidemiologic studies showed that particularly long-chain omega-3 fatty acids from animal sources have a positive impact on human health and disease. RESULTS: To screen for genetic factors affecting fatty acid profiles in beef, we initially performed a microsatellite-based genome scan in a F(2) Charolais × German Holstein resource population and identified a quantitative trait locus (QTL) for fatty acid composition in a region on bovine chromosome 27 where previously QTL affecting marbling score had been detected in beef cattle populations. The long-chain acyl-CoA synthetase 1 (ACSL1) gene was identified as the most plausible functional and positional candidate gene in the QTL interval due to its direct impact on fatty acid metabolism and its position in the QTL interval. ACSL1 is necessary for synthesis of long-chain acyl-CoA esters, fatty acid degradation and phospholipid remodeling. We validated the genomic annotation of the bovine ACSL1 gene by in silico comparative sequence analysis and experimental verification. Re-sequencing of the complete coding, exon-flanking intronic sequences, 3' untranslated region (3'UTR) and partial promoter region of the ACSL1 gene revealed three synonymous mutations in exons 6, 7, and 20, six noncoding intronic gene variants, six polymorphisms in the promoter region, and four variants in the 3' UTR region. The association analysis identified the gene variant in intron 5 of the ACSL1 gene (c.481-233A>G) to be significantly associated with the relative content of distinct fractions and ratios of fatty acids (e.g., n-3 fatty acids, polyunsaturated, n-3 long-chain polyunsaturated fatty acids, trans vaccenic acid) in skeletal muscle. A tentative association of the ACSL1 gene variant with intramuscular fat content indicated that an indirect effect on fatty acid composition via modulation of total fat content of skeletal muscle cannot be excluded. CONCLUSIONS: The initial QTL analysis suggested the ACSL1 gene as a positional and functional candidate gene for fatty acid composition in bovine skeletal muscle. The findings of subsequent association analyses indicate that ACSL1 or a separate gene in close proximity might play a functional role in mediating the lipid composition of beef.

Metabolic responses to high-fat diets rich in n-3 or n-6 long-chain polyunsaturated fatty acids in mice selected for either high body weight or leanness explain different health outcomes.

BACKGROUND: Increasing evidence suggests that diets high in polyunsaturated fatty acids (PUFA) confer health benefits by improving insulin sensitivity and lipid metabolism in liver, muscle and adipose tissue. METHODS: The present study investigates metabolic responses in two different lines of mice either selected for high body weight (DU6) leading to rapid obesity development, or selected for high treadmill performance (DUhTP) leading to a lean phenotype. At 29 days of age the mice were fed standard chow (7.2% fat, 25.7% protein), or a high-fat diet rich in n-3 PUFA (n-3 HFD, 27.7% fat, 19% protein) or a high-fat diet rich in n-6 PUFA (n-6 HFD, 27.7% fat, 18.6% protein) for 8 weeks. The aim of the study was to determine the effect of these PUFA-rich high-fat diets on the fatty acid profile and on the protein expression of key components of insulin signalling pathways. RESULTS: Plasma concentrations of leptin and insulin were higher in DU6 in comparison with DUhTP mice. The high-fat diets stimulated a strong increase in leptin levels and body fat only in DU6 mice. Muscle and liver fatty acid composition were clearly changed by dietary lipid composition. In both lines of mice n-3 HFD feeding significantly reduced the hepatic insulin receptor ß protein concentration which may explain decreased insulin action in liver. In contrast, protein kinase C ζ expression increased strongly in abdominal fat of n-3 HFD fed DUhTP mice, indicating enhanced insulin sensitivity in adipose tissue. CONCLUSIONS: A diet high in n-3 PUFA may facilitate a shift from fuel deposition in liver to fuel storage as fat in adipose tissue in mice. Tissue specific changes in insulin sensitivity may describe, at least in part, the health improving properties of dietary n-3 PUFA. However, important genotype-diet interactions may explain why such diets have little effect in some population groups.

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.

Dietary n-3 fatty acids significantly suppress lipogenesis in bovine muscle and adipose tissue: a functional genomics approach.

Changes in fatty acid composition of longissimus muscle and subcutaneous adipose tissue of German Holstein bulls induced by a grass-silage/n-3 fatty acid based intervention diet versus a maize-silage/n-6 fatty acid based control diet were analyzed and related to shifts in lipogenic gene expression, protein expression, and enzyme activity patterns. Significantly higher amounts of n-3 fatty acids and by mean factors of 2.2-2.5 decreased n-6/n-3 fatty acid ratios in both tissues were obtained upon n-3 fatty acid intervention. In longissimus muscle, these changes of fatty acid profiles were associated with reduced SREBP1c (p = 0.02), ACC (p = 0.00), FAS (p = 0.10) and SCD (p = 0.03) gene expression, Δ6D (p = 0.03) and SCD (p = 0.03) protein expression as well as SCD enzyme activity (p = 0.03). In subcutaneous adipose tissue, significantly reduced ACC (p = 0.00) and FAS (p = 0.01) gene expression, SCD protein expression (p = 0.02) and SCD enzyme activity (p = 0.03) were detected upon n-3 fatty acid intervention, although lower degrees of correlation between gene and corresponding gene products were obtained in relation to longissimus muscle. The study elucidates tissue-specific functional genomic responses to dietary fatty acid manipulation in regard to fatty acid profile tailoring of animal tissues.

Antioxidant enzyme activities and antioxidant capacity in longissimus muscle from bulls fed diets rich in polyunsaturated fatty acids.

The effect of a treatment diet composed of grass silage and concentrate including rapeseed (with/without feeding restriction) was compared with a control diet of maize silage/grass silage (70:30) and concentrate including soybean, on the antioxidant enzyme activities of fresh longissimus muscle from German Simmental bulls. Additionally, the effect of diet on antioxidant capacity (AOC) of hydrophilic and lipophilic antioxidants was evaluated in fresh and stored beef muscle using the FRAP-ferric reducing ability and TEAC - Trolox-equivalent antioxidant capacity assays at different reaction times. Catalase and superoxide dismutase activities were significantly higher in the treatment diet groups, and glutathione peroxidase activity was not different. AOC was not affected by the diet. However, storage affected the values of FRAP and TEAC assays, and the results were time-depending. 30min were found like a minimum reaction time for both assays. Generally, AOC values of the hydrophilic antioxidants were significantly higher than lipophilic values.

Effect of dietary n-3 and n-6 PUFA on lipid composition of different tissues of German Holstein bulls and the fate of bioactive fatty acids during processing.

The present study investigated the effects of dietary linolenic acid (ALA) versus linoleic acid (LA) on meat quality, fatty acid composition, and stearoyl-CoA desaturase (SCD) activity in longissimus muscle (MLD) and subcutaneous adipose tissue (SAT) of German Holstein bulls and the transfer of beneficial n-3 fatty acids into German corned beef sausages (GCB). Feeding LA- and ALA-enriched diets increased essential fatty acids in MLD and SAT. The ALA-supplemented diet decreased significantly the SCD activity in MLD and SAT, resulting in a reduced relative concentration of oleic acid in muscle. The relative proportion of CLAcis-9,trans-11 analyzed by HPLC was not different between groups in either tissue. GCB were produced by using the lean meat of bulls. Beef products of bulls fed the ALA-supplemented diet were rich in ALA and n-3 LC PUFA. Most importantly, there was no loss of n-3 fatty acids during processing under production conditions. Conclusively, the n-6/n-3 fatty acid ratio was beneficially low.

Relationship between lipid peroxidation and antioxidant status in the muscle of German Holstein bulls Fed n-3 and n-6 PUFA-enriched diets.

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

Assessment of the antioxidant potential of selected plant extracts--in vitro and in vivo experiments on pork.

The antioxidant potential of selected plant extracts was assessed in vitro and in vivo experiments on pork. In the in vitro experiment, the anti-oxidative capacity of ethanol-water extract of Melissa officinalis (MW), ethanol-propylene-glycol extracts of M. officinalis (MP), Origanum vulgaris (O) and Salvia officinalis (S) at different dilutions was analysed. Furthermore a 2% essential oil concentrate was added to Origanum (OSi) and Salvia (SSi). In the two in vivo experiments in total 104 Slovak White Meaty pigs were fed with plant extracts (MW and O) at different doses with/without additional vitamin E. In the in vitro experiment Melissa (MW) showed a higher antioxidant potential compared to Origanum and Salvia assessed by TEAC assay. Addition of essential oil to Origanum improved substantially the anti-oxidative capacity. In the in vivo experiment the highest muscle anti-oxidative effect was obtained by feeding 60 ml Origanum. Small improvement in muscle antioxidant potential was observed by feeding Melissa or Origanum in combination with vitamin E. By feeding 10 ml Melissa, Origanum or Salvia the meat quality parameters such as pH(1) and pH(24), drip loss and shear force was not affected. After 5 days storage of meat the redness value was positively affected.

The intact muscle lipid composition of bulls: an investigation by MALDI-TOF MS and 31P NMR.

The analysis of beef lipids is normally based on chromatographic techniques and/or gas chromatography in combination with mass spectrometry (GC/MS). Modern techniques of soft-ionization MS were so far scarcely used to investigate the intact lipids in muscle tissues of beef. The objective of the study was to investigate whether matrix-assisted laser desorption and ionization time-of-flight (MALDI-TOF) mass spectrometry and (31)P nuclear magnetic resonance (NMR) spectroscopy are useful tools to study the intact lipid composition of beef. For the MALDI-TOF MS and (31)P NMR investigations muscle samples were selected from a feeding experiment with German Simmental bulls fed different diets. Beside the triacylglycerols (TAGs), phosphatidylethanolamine (PE), phosphatidylcholine (PC) and phosphatidylinositol (PI) species the MALDI-TOF mass spectra of total muscle lipids gave also intense signals of cardiolipin (CL) species. The application of different matrix compounds, 2,5-dihydroxybenzoic acid (DHB) and 9-aminoacridine (9-AA), leads to completely different mass spectra: 9-AA is particularly useful for the detection of (polar) phospholipids, whereas apolar lipids, such as cholesterol and triacylglycerols, are exclusively detected if DHB is used. Finally, the quality of the negative ion mass spectra is much higher if 9-AA is used.