Expression of lipogenic genes in the muscle of beef cattle fed oilseeds and vitamin E

The objectives of the study were to evaluate the expression of genes related to lipid metabolism in skeletal muscle and liver gluconeogenesis in Nellore steers fed a magnesium oxide blend combined or not with monensin. Eighty-four Nellore steers (367.3 ± 37.89 kg) were used in a completely randomized design. Animals were stratified by body weight, housed in 28 pens (3 animals/pen and 7 pens/treatment), and assigned to one of the four treatments. The treatments were: control (CON) – steers fed a basal diet without any dietary additive; magnesium oxide blend (MgO) – the basal diet supplemented with a magnesium oxide blend (pHix-up®, Timab Magnesium, Dinard, France) included at a level of 0.50 % of dry matter (dry matter); monensin (MON) - the basal diet supplemented with 25 mg/kg of DM of sodium monensin (Rumensin, Elanco Animal Health, Greenfield, IN); and MgO combined with MON (MgO + MON). Animals were fed a basal finishing diet (77.8 % total digestible nutrients, and 13.3 % crude protein) for 100 days. At 70 d on feed, biopsy samples were collected in the longissimus thoracis (LT) muscle and liver. After the feeding period, animals were slaughtered in a commercial abattoir and samples were again collected in the LT muscle. All tissue samples were immediately frozen in liquid nitrogen, then stored at -80 ºC until further analysis. Gene expression was assessed using RT-qPCR technique. Data were analyzed using the MIXED procedure of SAS 9.4 with fixed effects of dietary treatment and random effects of pen nested within treatment. No treatment differences were observed (P > 0.11) in the PC, LDHA, and PCK1 expressions in the liver at 70 d on feed. However, PCCA expression tended to be upregulated (P = 0.06) in MgO steers than in CON and MON steers. In the LT muscle at 70 d on feed, treatments did not affect (P > 0.11) ACACA, CPT1A, PPARA, and ACLY expressions. The SLC2A4 expression was downregulated (P = 0.04) in steers fed MON, MgO, or MgO + MON in comparison to CON animals. Thus, MgO + MON steers upregulated (P = 0.05) the SREBF1 expression compared to MON and MgO. At slaughter, no differences were observed (P > 0.12) in CPT1A, PPARA, and SREBF1 expressions. On the other hand, SLC2A4 expression tended to be upregulated (P = 0.06) in MON and MgO + MON compared to CON steers. In addition, the expressions of ACACA tended to be downregulated (P = 0.06) and ACLY was downregulated (P = 0.04) in CON steers compared to other treatments. In summary, under the conditions of the present study, the additives inclusion and its combination were capable of slightly modify the expression of genes related to gluconeogenesis and lipid metabolism.

The objective was to evaluate marbling and the expression of genes involved in lipid metabolism in the muscle of Nellore and Nellore × Angus steers fed whole shelled corn (WSC) diets. Thirty-two steers with initial average body weight of 353 ±25.3 kg were used in a completely randomized design using a 2 × 2 factorial design (2 breeds and 2 diets). One diet had 80% of WSC and 20% of a soybean meal and mineral-based supplement. The other diet had 74% of WSC, 20% of the same supplement, and 6% of sugarcane bagasse. Immediately after the slaughter of steers (around 450 kg of body weight), longissimus thoracis (LT) muscle samples were collected, frozen in liquid nitrogen, and stored at −80°C for gene expression analyses using RT-qPCR. Twenty-four hours after slaughter, samples were taken from LT muscle to analyze marbling score. The model included breed, diet, and their interaction as fixed effects and animals as random effect. There was no effect of breed (364 and 358; P = 0.80) and diet (355 and 367; P = 0.56) on LT marbling. Nellore × Angus steers had greater expression of LPL, FASN, and CPT2 (Table 1), which means a greater lipid turnover. The expression of SCD1 gene tended to increase (P = 0.06) in muscle of Nellore steers fed WSCB diet, while in Nellore × Angus muscle, this diet tended to decreased SCD1 expression. Regarding diet, steers fed WSC had lower expression of FABP4, and greater expression of ACOX1. In conclusion, Nellore × Angus had greater fatty acid uptake, synthesis, and oxidation that did not result in greater intramuscular fat. In addition, animals fed whole shelled corn diet with sugarcane bagasse did not increase expression of SREBF1 and lipogenic genes, and consequently did not increase marbling. Funded by Capes, Fapemig and INCT-Ciência Animal.

The inclusion of agro-industry by-products originated from corn ethanol production has increased in animal nutrition in Brazil, reducing formulation costs. In the literature, there is no consensus on how the high inclusion of de-oiled wet distillers grains can affect beef quality and the expression of lipogenic genes in Longissimus muscle. The aim of this study was to evaluate the effects of WDG in the diet of F1 Angus-Nellore cattle on meat quality characteristics, chemical composition and expression of genes involved in lipid metabolism. A hundred F1 Angus-Nellore bulls, with average initial body weight (BW) of 369.5 ± 49 kg were used. The experiment was carried out in a randomized block design, and the animals were divided into two blocks (light and heavy) according to the initial body weight. The animals were fed diets containing levels of 0 (control), 15, 30 and 45% of WDG replacing dry corn and soybean meal. After 129 days of feedlot, the animals were slaughtered and samples of the longissimus thoracis (LT) muscle were collected for quality analyzes such as shear force (3, 10 and 17 aging days), color (luminosity, red, Chroma and Hue), cooking losses, pH and chemical composition (moisture, protein, lipids and ash contents). In addition, the expression of the PPARα, PPARγ, SREBP-1c, SCD1, LPL, FABP4, FASN, ACOX, CPT2, GPX1 and ACACA genes was investigated in the LT muscle by real-time reverse transcription polymerase chain reaction (RT-PCR). Data were analyzed using polynomial contrasts (linear, quadratic and control vs. WDG). There was no interaction (P > 0.05) between aging times and the inclusion of WDG in the diets on the meat quality (pH, cooking losses, coloration and tenderness). However, diets with increasing levels of WDG caused a linear reduction (P = 0.01) in the intramuscular fat of LT. The lipogenic genes SCD1, PPARγ, FASN and CPT2 were less expressed (P < 0.05) in response to the inclusion of WDG. These results suggest that the inclusion of WDG reduced the expression of lipogenic genes and consequently the marbling of LT muscle without affecting tenderness (shear force) and meat color traits.

The effect of feeding system in the expression of genes related with fat metabolism in semitendinous muscle in sheep

Conjugated linoleic acid (CLA), a mixture of isomers of linoleic acid, has previously been shown to be able to decrease porcine subcutaneous (SC) adipose tissue levels while increasing the count of intramuscular (IM) adipose tissue in vivo. However, the underlying mechanisms through which it acts are poorly understood. The objective of this study was to investigate the different effects of CLA on adipogenesis in cultured SC adipose tissue and IM stromal vascular cells obtained from neonatal pigs. As shown here, trans-10, cis-12 CLA decreased the expression of adipocyte-specific genes as well as adipose precursor cell numbers and the accumulation of lipid in cultured SC adipose tissue stromal vascular cells. However, the cis-9, trans-11 CLA did not alter adipogenesis in SC cultures. On the other hand, both CLA isomers increased the expression of adipocyte-specific genes in IM cultures, together with the increasing accumulation of lipid and Oil Red O-stained cells. Collectively, these data show that CLA decreases SC adipose tissue but increases IM adipose tissue by different regulation of adipocyte-specific gene expression. These results suggest that adipogenesis in IM adipocytes differs from that in SC adipocytes.

Effects of perilla frutescens seed supplemented to diet on fatty acid composition and lipogenic gene expression in muscle and liver of Hu lambs

Degree of unsaturation of fatty acids, which is influenced by lipid source and level of metabolism in the rumen, is a major determinant in how dietary lipids affect genes that regulate beef marbling. A total of 28 Red Norte bulls with an initial live weight of 361±32 kg (P>0.05) were used in a completely randomized experimental design to analyze the expression of genes that are involved in lipid metabolism in the longissimus dorsi (LD) when diets contained soybean grain or rumen-protected fat, with or without monensin. Treatments were arranged as a 2×2 factorial, with 4 treatments and 7 replicates per treatment. Half of the animals that received soybean or rumen-protected fat were supplemented with 230 mg head(-1) d(-1) of monensin. Gene expression was analyzed by reverse-transcription quantitative PCR (RT-qPCR). Expression of sterol regulatory element-binding protein-1c (SREBP-1c) in the LD muscle was not affected by lipid source or monensin (P>0.05). There was an interaction effect (P<0.05) between lipid source and monensin for peroxisome proliferator-activated receptor α (PPAR-α) and stearoyl-CoA desaturase (SCD) expression, where greater gene expression was found in animals fed soybean plus monensin and the lower gene expression was found in animals fed rumen-protected fat plus monensin. Expression of lipoprotein lipase (LPL) and fatty acid-binding protein 4 (FABP4) were greater (P<0.05) in the LD muscle of animals fed soybean. Monensin had no effect on LPL and FABP4 expression when soybean without monensin was fed, but when rumen-protected fat was fed, monensin increased LPL expression and decreased FABP4 expression (P<0.05). Linoleic and arachidonic acids had negative correlations (P<0.05) with the expression of PPAR-α, SCD, FABP4, and LPL genes. PPAR-α gene expression was not correlated with SREBP-1c but was positively correlated with SCD, FABP4, LPL, and glutathione peroxidase (GPX1) gene expression (P<0.001). Lipid sources and monensin interact and alter the expression of PPAR-α, SCD, acetyl CoA carboxylase α (ACACA), LPL, FABP4, and GPX1. These changes in gene expression were most associated with arachidonic and α-linolenic acids and the ability of lipid sources and monensin to increase these fatty acids in tissues.

IntroductionThis study investigated the impact of creep-feeding supplementation on the genome methylation of the Longissimus thoracis (LT) muscle in crossbred beef cattle (Bos taurus × Bos indicus).MethodsThe experiment involved 48 uncastrated F1 Angus-Nellore males (half-siblings), which were divided into two groups: NCF – no creep-feeding (n = 24) and CF – creep-feeding (n = 24). After weaning at 210 days, all animals were feedlot finished for 180 days under identical conditions. LT muscle biopsies were collected at weaning for genomic DNA methylation analysis by reduced representation bisulfite sequencing (RRBS).Results and discussionThe groups differed significantly (CF &amp;gt; NCF: p &amp;lt; 0.05) to weaning weight (243.57±5.70 vs. 228.92±5.07kg), backfat thickness (12.96±0.86 vs. 10.61±0.42mm), LT muscle marbling score (366.11±12.39 vs. 321.50±13.65), and LT intramuscular fat content (5.80±0.23 vs. 4.95±0.20%). The weights at the beginning of the experiment and at slaughter (390 days) did not differ significantly. Mean methylation levels were higher in CF with 0.18% more CpG, 0.04% CHG, and 0.03% CHH. We identified 974 regions with differential methylation (DMRs: &amp;gt; 25% and q &amp;lt; 0.05), which overlapped with 241 differentially methylated genes (DMGs). Among these genes, 108 were hypermethylated and 133 were hypomethylated in CF group. Notably, 39 of these DMGs were previously identified as differentially expressed genes (DEGs: log2 fold change [0.5]) in the same animal groups. Over-representation analysis highlighted epigenetic regulations related to muscle growth, PPAR signaling, adipogenesis, insulin response, and lipid metabolism. Key DMGs/DEGs included: ACAA1, SORBS1, SMAD3, TRIM63, PRKCA, DNMT3A, RUNX1, NRG3, and SLC2A8. These epigenetic changes improved the performance of supplemented animals up to weaning and enhanced meat quality traits, particularly higher intramuscular fat. The results provided insights into the intricate interplay between nutrition, epigenetics, gene expression and phenotypes in beef cattle production.

Expression of genes involved in adipogenesis and lipid metabolism in subcutaneous adipose tissue and longissimus muscle in low-marbled Pirenaica beef cattle

Peroxisome proliferator-activated receptor-γ activation and long-chain fatty acids alter lipogenic gene networks in bovine mammary epithelial cells to various extents

Subspecies and diet affect the expression of genes involved in lipid metabolism and chemical composition of muscle in beef cattle

BackgroundThe objective of this study was to evaluate the effects of dietary fatty acids (FA) saturation and lysophospholipids supplementation on growth, meat quality, oxidative stability, FA profiles, and lipid metabolism of finishing beef bulls. Thirty-two Angus bulls (initial body weight: 623 ± 22.6 kg; 21 ± 0.5 months of age) were used. The experiment was a completely randomized block design with a 2 × 2 factorial arrangement of treatments: 2 diets with FA of different degree of unsaturation [high saturated FA diet (HSFA) vs. high unsaturated FA diet (HUFA)] combined with (0.075%, dry matter basis) and without lysophospholipids supplementation. The bulls were fed a high-concentrate diet (forage to concentrate, 15:85) for 104 d including a 14-d adaptation period and a 90-d data and sample collection period.ResultsNo interactions were observed between dietary FA and lysophospholipids supplementation for growth and meat quality parameters. A greater dietary ratio of unsaturated FA (UFA) to saturated FA (SFA) from 1:2 to 1:1 led to lower DM intake and backfat thickness, but did not affect growth performance and other carcass traits. Compared with HSFA, bulls fed HUFA had greater shear force in Longissimus thoracis (LT) muscle, but had lower intramuscular fat (IMF) content and SOD content in LT muscle. Compared with HUFA, feeding the HSFA diet up-regulated expression of ACC, FAS, PPARγ, and SCD1, but down-regulated expression of CPT1B. Compared with feeding HSFA, the HUFA diet led to greater concentrations of c9-C18:1 and other monounsaturated FA in LT muscle. Feeding HUFA also led to lower plasma concentrations of cholesterol, but there were no interactions between FA and lysophospholipids detected. Feeding lysophospholipids improved growth and feed conversion ratio and altered meat quality by increasing muscle pH24h, redness values (24 h), IMF content, and concentrations of C18:3, C20:5 and total polyunsaturated fatty acids. Furthermore, lysophospholipids supplementation led to lower malondialdehyde content and up-regulated the expression of ACC, FAS, and LPL in LT muscle.ConclusionsResults indicated that supplementing a high-concentrate diet with lysophospholipids to beef bulls can enhance growth rate, feed efficiency, meat quality, and beneficial FA. Increasing the dietary ratio of UFA to SFA reduced DM intake and backfat thickness without compromising growth, suggesting potential improvements in feed efficiency.

N-3 long-chain (LC) PUFA are known to be beneficial for human development and health. These properties explain the increasing interest in promoting n-3 LC PUFA deposition in bovine muscles, leading to healthier meats. In this context, this study aimed to identify possible limiting steps in the bioconversion of 18:3n-3 into n-3 LC PUFA in the longissimus thoracis (LT) muscle of 36 Aberdeen Angus, Limousin, and Blond d'Aquitaine bulls (n = 12 per breed) that were fed, for the 105-d finishing period, either a concentrate-based diet (25% molasses straw to 75% concentrate, on a raw basis; CON) or the same CON diet supplemented with extruded linseed (44.5 g lipid/kg diet DM) mixed into the concentrate (LINS). The fatty acid (FA) composition of the LT muscle was determined by GLC, and the mRNA abundances for enzymes and transcription factors involved in n-3 LC PUFA synthesis were determined by quantitative real-time PCR. The total lipid concentration in the LT muscle was approximately 2.4-fold greater (P < 0.001) in Angus bulls than in the other breeds and composed of the greatest n-3 PUFA content (P < 0.001) including 18:3n-3 (P < 0.001) and n-3 LC PUFA (P < 0.02), primarily 20:5n-3 (P < 0.007) and 22:5n-3 (P < 0.04). These data were associated with a lesser gene expression (P < 0.02) of 2 enzymes [acyl-CoA oxidase 1 (ACOX1) and L-bifunctional protein (L-PBE)] and 2 transcription factors [liver X receptors (LXR) α and β] in the LT muscle of Angus bulls compared with gene expression in Limousin bulls. Moreover, the mRNA of elongase 5 was only present in trace amounts in the LT muscle of the 3 breeds. The addition of linseed to the diet resulted in greater deposition of 18:3n-3 (P < 0.001) in the LT muscles of the 3 breeds, without any major changes (P > 0.34) in the n-3 LC PUFA content. Dietary linseed stimulated (P < 0.04) the gene expression of all enzymes and transcription factors involved in n-3 LC PUFA synthesis except elongases 2 and 5 (P > 0.19), the expression of which remained weak and was not inducible. These results reveal a limited capacity for n-3 LC PUFA synthesis from 18:4n-3 (substrate of elongase 5) in the LT muscles of Blond d'Aquitaine, Limousin, and Angus bulls. Therefore, further investigations on the cellular regulation of elongase gene expression are needed to identify the physiological or nutritional factors that efficiently stimulate elongase expression in beef cattle.

The objective of this study was to evaluate the effect of corn silage particle size on beef quality and expression of gluconeogenic and lipogenic genes in feedlot-finished Nellore heifers. Nellore heifers (n = 94), with an initial body weight (BW) of 249.71 ± 34.62, were allotted into 32 pens (three animals per pen) in a completely randomized design, with 2 treatments and 16 repetitions. The treatments were corn silage with a particle size of 13 mm (short) or 24 mm (long). The feeding period lasted 101 d, with the first 15 d for diet adaptation. After slaughter, samples of the longissimus thoracis muscle (LT) from the left side of the half carcass and liver were taken for beef quality and gene expression analyses. The chemical composition of the beef was analyzed using near infrared according to the AOAC method 2007-04, using the FoodScanTM equipment (AOAC method: 2007-04; FOSS, Hillerod, Denmark). RT-qPCR analyses of each gene investigated were carried out using cDNA from 16 biological replicates per treatment (1 heifer chosen randomly in each pen), with each biological replicate subjected to 2 technical replicates. Relative gene expression analyses were calculated using the delta delta ct method and the reference genes used were ACTB and GAPDH. The normality of all experimental data was checked using the Shapiro-Wilk test in SAS software. When the data did not present a normal distribution, transformation was performed using PROC RANK. The model included particle size as a fixed effect and pen as a random effect. There was no treatment effect on collagen, moisture, and mineral content (P &amp;gt; 0.10), but muscles from heifers fed short particle sizes tended to have greater protein content (23.3 versus 22.9; P = 0.098), while muscles from heifers fed with long particles had greater intramuscular fat content (2.62 versus 3.28; P = 0.05). For liver gene expression, heifers fed short particle sizes tended to have greater expression of the PC gene (1.00 versus 0.82; P = 0.06), while PEPCK2 had higher expression in heifers fed long particles (1.00 versus 1.18; P = 0.04). In addition, the long particle size of corn silage affected the expression of PPARA (P = 0.001), and there was no effect of diets (P &amp;gt; 0.05) on PPARG and SREBF1 expressions (Table 1). Expression of LPL, FABP4, SCD1, CPT2 (P &amp;lt; 0.001), and ACACA (P = 0.017) genes increased in the muscle of heifers fed long particle size. Therefore, it is concluded that the use of corn silage with long particle size in feedlot diets has the potential to increase the expression of genes involved in lipogenesis and then increase intramuscular fat in Nellore heifers.

Effects of natural grazing (NG) or grazing with supplementary feeding (GS) of Hulunbeier lambs (HL) and Hulunbeier × Dorper crossbred lambs (HZ) on fatty acid (FA) profile and lipogenic gene expressions in the longissimus thoracis (LT) and subcutaneous adipose tissue (SAT) were determined. The study was conducted as a 2 × 2 factorial arrangement using four-month old lambs. Thirty animals were divided into each group. The FA composition and the expression of lipid metabolism gene of sheep were affected by the feeding regimens and animal breeds. Compared with NG, GS increases de novo FA synthesis of LT and SAT, which decreases GS lambs’ FA nutrition value. Meat or fat from NG lambs present more n-3 long-chain polyunsaturated FA that is beneficial to human health. Under the two feeding regimens, de novo synthesis of FA and fat deposition seems to higher in HZ lambs compared with those in HL as the expression of genes (SREBP1c, FAS, ACC, C/EBPα, PPARγ) that are associated with correlative metabolism was increased in HZ lambs. Meat from HZ lambs displays a less favourable level of saturated FA as containing higher content of C14:0, but it also presents higher profile of EPA than HL lambs.HighlightsFeeding ways and breeds affect fatty acids and gene.Meat from grazing lambs is beneficial to human health.Supplementary feeding increases fat deposition.