Longissimus Lumborum Muscle Samples Research Articles

Identification of eQTLs and differential gene expression associated with fetal programming in beef cattle.

This study assessed differential gene expression and identified expression quantitative trait loci (eQTLs) from samples of Longissimus lumborum muscle from bulls at 15months of age submitted to different prenatal nutrition. Upon confirmation of pregnancy, 126 dams were separated into three diet treatments varying the period of inclusion of energy protein supplementation (NP, PP, and FP). At calving, 63 males were genotyped with GGP LD BeadChip. The skeletal muscle of 15 bulls was sequenced (RNA-seq) at 15months of age. The EdgeR package was used for differential gene expression and principal component analysis (PCA), and the Matrix eQTL package was used for the eQTLs analysis (R statistical). The functional enrichment analysis was performed using the MetaCore® software. No genes differentially expressed were found between treatments (FDR > 0.05); nevertheless, we found 179 cis-tag-eQTLs and 20,762 trans-tag-eQTLs (FDR < 0.05) after linkage disequilibrium analysis. The functional enrichment analysis identified terms from gene ontology related to genes associated to trans-eQTLs (FDR < 0.05) as well as metabolic pathways (> gScore). Most biological pathways and genes found had been previously associated to fetal programming. The different prenatal supplementation strategies did not impact on muscle transcriptome of bulls. Additionally, there is a link between genotype and gene expression levels related to developmental traits in Nellore cattle.

Ractopamine-induced remodeling in the mitochondrial proteome of postmortem longissimus lumborum muscle from feedlot steers

Dietary ractopamine causes a muscle fiber shift in cattle, and the biochemistry of mitochondria in postmortem muscles is influenced by fiber type. Nonetheless, the influence of ractopamine on beef skeletal muscle mitochondrial proteome has not been evaluated. Therefore, the objective of this study was to examine the effects of dietary ractopamine on mitochondrial proteome of postmortem longissimus lumborum (LL) from feedlot crossbred steers. Pen-housed crossbred steers were fed either a corn-based basal diet (CON) or a diet top-dressed with Optaflexx 45 (Elanco Animal Health) to provide 400 mg of ractopamine hydrochloride/steer per day (RAC). Ractopamine was fed the last 28 days prior to the harvest. The LL muscle samples were obtained from nine (n = 9) RAC and nine (n = 9) CON carcasses. The mitochondrial proteome was analyzed using two-dimensional gel electrophoresis and mass spectrometry. Seven differentially abundant proteins (P < 0.05) were identified. Three proteins over-abundant in RAC were complement component 1 Q subcomponent-binding protein (C1QBP), very long-chain specific acyl-CoA dehydrogenase (ACADVL), and aconitate hydratase (ACO2). On the other hand, four proteins, ATP synthase subunit beta (ATP5B), prohibitin (PHB), cytochrome b-c1 complex subunit (UQCRC1), and thioredoxin-dependent peroxide reductase (PRDX3), were over-abundant in CON. The differentially abundant proteins belong to four functional groups – energy metabolism (ATP5B, UQCRC1, and ACO2); chaperone activity (C1QBP and PHB); redox metabolism (PRDX3); and fatty acid degradation (ACADVL). The increased protein synthesis and leanness reported in ractopamine-fed cattle may be attributed to the increased expression of enzyme involved in fatty acid degradation and the decreased expression of enzymes involved in oxidative phosphorylation. Additionally, the decreased tenderness previously reported in beef from ractopamine-fed cattle may be attributed to the increased expression of antiapoptotic protein (C1QBP) and decreased expression of proapoptotic protein (PHB) resulted from ractopamine supplement.

Comparison of D65/10° and A/10° illuminant/observer systems for colour measurement of raw pork [pdf

BACKGROUND In pork colour measurements, the value of each parameter depends on the type of illuminant used. The spectra of D65 and A illuminants show great differences, with illuminant A having greater emission in the red part of the visible spectrum. Therefore, its application in the colour measurements of the pork longissimus muscle should result in larger changes in redness (Δa*) and hue angle (Δh°) and higher correlation between Δa* and Δh° and pH48 and WHC. The purpose of this study was to compare the suitability of the illuminant/observer systems D65/10° and A/10° for colour measurements of pork longissimus muscle, using the CIELAB and CIELCh systems. METHODS The study involved 168 samples of longissimus lumborum muscle taken from 168 carcasses (mean weight 90.2 ±6.0 kg) of pigs slaughtered on an industrial processing line. The moisture content, crude protein, intramuscular fat content, WHC, and pH48 were determined. Colour measurements using CIELAB and CIELCh scales were carried out with both D65/10° and A/10° illuminant/observer systems and reflectance measurements. The chromatic absorbance value at 525 nm (A525p) and the relative amounts of MbO2, MetMb, and Mb were calculated according to methods proposed by Krzywicki (1979) and AMSA (2012). Meat samples were illuminated and differences in the values of colour parameters (ΔL*, Δa*, Δb*, ΔC*, Δh°), chromatic absorbance at 525 nm (ΔA525p), and in the relative amounts of chemical forms of myoglobin (ΔMbO2, ΔMetMb, ΔMb) were determined. In addition, hue difference (ΔH) and total difference (ΔE) were calculated. RESULTS The values of correlation coefficients between moisture content (especially crude protein and intramuscular fat, and colour parameters) were low and often statistically insignificant. Higher and mostly significant values of correlation coefficients were found between colour parameters and WHC and pH48. The A/10° system resulted in higher values of correlation coefficients than D65/10° between (I) WHC, pH48 and (II) h°, Δa* and Δh°. At the same time, in the A/10° system the combined effect of the relative amounts of myoglobin chemical forms on the variation of h° values and the combined effect of changes (Δ) in their amounts on the variation of Δh° and ΔH and ΔE were greater than in D65/10°, with the greatest effect of these changes (Δ) in the amount of MetMb. CONCLUSIONS Replacement of the illuminant/observer D65/10° system with the A/10° system in colour measurements of raw pork longissimus muscle changed the proportion of pigments and the relative number of chemical forms of myoglobin in influencing the values of colour parameters, primarily h°. Therefore, using the A/10° system for colour measurements allows us to better capture the differences (Δ) in redness Δa* and especially in hue angle (Δh°), as well as hue difference (ΔH) and total difference (ΔE), with an increase in the relative amount of MetMb becoming the main determinant of these differences (Δ). At the same time, measurements using the A/10° system increased the correlation coefficients between WHC and pH48 and changes in redness (Δa*) and hue angle (Δh°). Therefore, the A/10° system compared to the D65/10° system may be more useful for measuring the colour stability of raw pork, especially the determination of Δh° and ΔH and ΔE. >.

Comparison of D65/10&deg; and A/10&deg; illuminant/observer systems for colour measurement of raw pork.

In pork colour measurements, the value of each parameter depends on the type of illuminant used. The spectra of D65 and A illuminants show great differences, with illuminant A having greater emission in the red part of the visible spectrum. Therefore, its application in the colour measurements of the pork longissimus muscle should result in larger changes in redness (&Delta;a*) and hue angle (&Delta;h&deg;) and higher correlation between &Delta;a* and &Delta;h&deg; and pH48 and WHC. The purpose of this study was to compare the suitability of the illuminant/observer systems D65/10&deg; and A/10&deg; for colour measurements of pork longissimus muscle, using the CIELAB and CIELCh systems. The study involved 168 samples of longissimus lumborum muscle taken from 168 carcasses (mean weight 90.2 &plusmn;6.0 kg) of pigs slaughtered on an industrial processing line. The moisture content, crude protein, intramuscular fat content, WHC, and pH48 were determined. Colour measurements using CIELAB and CIELCh scales were carried out with both D65/10&deg; and A/10&deg; illuminant/observer systems and reflectance measurements. The chromatic absorbance value at 525 nm (A525p) and the relative amounts of MbO2, MetMb, and Mb were calculated according to methods proposed by Krzywicki (1979) and AMSA (2012). Meat samples were illuminated and differences in the values of colour parameters (&Delta;L*, &Delta;a*, &Delta;b*, &Delta;C*, &Delta;h&deg;), chromatic absorbance at 525 nm (&Delta;A525p), and in the relative amounts of chemical forms of myoglobin (&Delta;MbO2, &Delta;MetMb, &Delta;Mb) were determined. In addition, hue difference (&Delta;H) and total difference (&Delta;E) were calculated. The values of correlation coefficients between moisture content (especially crude protein and intramuscular fat, and colour parameters) were low and often statistically insignificant. Higher and mostly significant values of correlation coefficients were found between colour parameters and WHC and pH48. The A/10&deg; system resulted in higher values of correlation coefficients than D65/10&deg; between (I) WHC, pH48 and (II) h&deg;, &Delta;a* and &Delta;h&deg;. At the same time, in the A/10&deg; system the combined effect of the relative amounts of myoglobin chemical forms on the variation of h&deg; values and the combined effect of changes (&Delta;) in their amounts on the variation of &Delta;h&deg; and &Delta;H and &Delta;E were greater than in D65/10&deg;, with the greatest effect of these changes (&Delta;) in the amount of MetMb. Replacement of the illuminant/observer D65/10&deg; system with the A/10&deg; system in colour measurements of raw pork longissimus muscle changed the proportion of pigments and the relative number of chemical forms of myoglobin in influencing the values of colour parameters, primarily h&deg;. Therefore, using the A/10&deg; system for colour measurements allows us to better capture the differences (&Delta;) in redness &Delta;a* and especially in hue angle (&Delta;h&deg;), as well as hue difference (&Delta;H) and total difference (&Delta;E), with an increase in the relative amount of MetMb becoming the main determinant of these differences (&Delta;). At the same time, measurements using the A/10&deg; system increased the correlation coefficients between WHC and pH48 and changes in redness (&Delta;a*) and hue angle (&Delta;h&deg;). Therefore, the A/10&deg; system compared to the D65/10&deg; system may be more useful for measuring the colour stability of raw pork, especially the determination of &Delta;h&deg; and &Delta;H and &Delta;E. >.

Fatty acid profile and lipid indices of the porker meat supplemented with pro-health herbal probiotics, ascorbic acid and allicin

PurposeThe objective of this study is to assess whether pro-health herbal probiotics, ascorbic acid and allicin added to the finishing diets of hybrid pig influenced the intramuscular fat (IMF) content in longissimus lumborum (LL) muscle, the fatty acid profile and lipid quality indices, as it has an impact on human health.Design/methodology/approachAfter 80 days of equal fattening, the pigs were divided into the control group (CT, n = 30 received commercially allowed and applicable antibiotics) and the experimental group (EX, n = 30), which until 95 days of rearing were supplied with fermented herbs extract (FHE Multikraft® Austria) with probiotics Saccharomyces cerevisiae, Lactobacillus casei, Lactobacillus plantarum, L-ascorbic acid and extract of garlic (10% allicin). After slaughter, crude fat content and fatty acid profile were determined in LL muscle samples, and on that basis lipid indices were calculated.FindingsSupplementation with FHE, probiotics, L-ascorbic acid and allicin has significantly impacted the crude fat content in the meat and the percentage of fatty acids content: tricosanoic (C23:0), heptadecanoid (C17:1 n-7), eicosanic (C22:1 11cis n-9) and eicosatrienoic (C20:3 11cis n-3), in comparison to CT group. Amongst lipid quality indices, IMF in LL of pigs from EX group, the C18:2 n-6/C18:3 n-3 ratio is characterised by a significantly higher value and thus is more beneficial to the health of the consumer.Originality/valueThe authors have indicated that using FHE, probiotic supplements with ascorbic acid and allicin in commercial fattening of pigs, as an alternative for antibiotic growth promoters (AGP), improves the fatty acid profile of the meat.

ITRAQ-mediated analysis of the relationship between proteomic changes and yak longissimus lumborum tenderness over the course of postmortem storage

To identify differentially expressed proteins associated with energy metabolism and tenderness during the postmortem aging of yak longissimus lumborum muscle samples, we collected tissue samples from yaks raised at different altitudes. At 12 h post-slaughter, we identified 290 differentially expressed proteins (DEPs) in these samples, whereas 436 such DEPs were detected after 72 h. Identified DEPs were clustered into four main functional categories: cell structural proteins, glycogen metabolic proteins, energy reserve metabolic proteins, and cellular polysaccharide metabolic proteins. Further bioinformatics analysis revealed that these proteins were associated with carbon metabolism, glycolysis, and the biosynthesis of amino acids. Our functional insights regarding these identified proteins contribute to a more detailed molecular understanding of the processes of energy metabolism in yak muscle tissue, and represent a valuable resource for future investigations.

Temperature-time combination effects on aged beef volatile profiles and their relationship to sensory attributes

Beef ageing (in vacuo) for tenderisation and flavour development may be accelerated by favourable temperature-time combinations (TTCs), however the effect of such manipulations on volatile organic compounds (VOCs) that are generated during cooking, is unknown. We compared VOCs from grilled beef longissimus lumborum muscle samples which had been subjected to different TTCs. The TTCs consisted of combinations of temperatures (~ 3, 5, or 7 °C) and ageing time periods (6, 8, 10 or 12 d); as well as control samples, which were held at 0-2 °C for a total of 14 d. Sensory quality attributes of these same samples were measured by untrained consumer panellists. Generally, it was found that TTCs had negligible effects on grilled beef VOCs and were comparable to controls. Furthermore, many VOCs were significantly related to flavour intensity, flavour liking and overall liking. These findings support the use of TTCs as a viable means to accelerate the rate of beef ageing without compromising quality.

Supranutritional Supplementation of Vitamin E Influences the Abundance of Antioxidant Proteins in Postmortem Longissimus Lumborum from Heifers

ObjectivesVitamin E is a lipid-soluble antioxidant that can inhibit lipid oxidation and improve beef color stability. The effect of vitamin E on fresh beef color, from the standpoint of lipid oxidation-induced myoglobin oxidation, have been extensively studied. However, the influence of vitamin E on sarcoplasmic proteome profile of beef skeletal muscles is yet to be investigated. Therefore, the objective of this study was to examine the effect of dietary vitamin E on sarcoplasmic proteome of postmortem beef longissimus lumborum (LL) muscle.Materials and MethodsCrossbred heifers, managed with a GrowSafe feeding system, were fed ad libitum corn-based diet containing either no supplemental (CONT) or 1000 IU vitamin E/heifer per day (VITE) for 89 d. The animals were harvested, and carcasses were chilled. The LL muscle samples were obtained from the carcasses of nine (n = 9) VITE and nine (n = 9) CONT heifers 24 h postmortem. The muscle samples were individually vacuum-packaged and frozen at –80°C for proteome analysis. Sarcoplasmic proteome was analyzed using two-dimensional electrophoresis, employing immobilized pH gradient strips (pH 3–10; 17 cm) in the first dimension and 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis in the second dimension. The gels were scanned, and the digital gel images were analyzed. The protein spots exhibiting more than 1.5-fold intensity differences (P &lt; 0.10) between VITE and CONT were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsFive differentially abundant spots were identified using mass spectrometry, and all the spots were over-abundant in CONT. The proteins in the differentially abundant spots were antioxidant proteins (thioredoxin-dependent peroxide reductase, peroxiredoxin-6, and serum albumin) and glycolytic enzymes (β-enolase and triosephosphate isomerase). The antioxidant proteins minimize oxidation of lipids and proteins in muscle matrix, whereas the glycolytic enzymes generate NADPH, which helps maintain the antioxidant proteins in their reduced forms.ConclusionThe strong antioxidant protection offered by vitamin E could have possibly led to less expression of antioxidant proteins as well as glycolytic enzymes that generate antioxidant metabolites in the VITE group, whereas the lack of such protection in CONT group may have led to increased expression of these proteins in the skeletal muscles.

Ractopamine-Induced Changes in the Mitochondrial Proteome of Postmortem Beef Longissimus Lumborum

ObjectivesRactopamine is a β-adrenergic agonist approved as growth promotant in beef cattle, and it increases muscle deposition while limiting fat deposition. Dietary ractopamine causes a muscle fiber shift in cattle, and the biochemistry of mitochondria in postmortem beef skeletal muscles is influenced by fiber type. Therefore, dietary ractopamine may potentially affect mitochondrial functionality. Nonetheless, the influence of ractopamine on beef skeletal muscle mitochondrial proteome has not been evaluated. Therefore, the objective of this study was to examine the effects of ractopamine on mitochondrial proteome of postmortem longissimus lumborum (LL) from beef cattle.Materials and MethodsPen-housed crossbred steers were fed either a corn-based basal diet (CON) or a diet top-dressed with Optaflexx 45 (Elanco Animal Health) to provide 400 mg of ractopamine hydrochloride/steer per day (RAC). Ractopamine was fed the last 28 d prior to the harvest. The animals were harvested, and carcasses were chilled for 24 h. The LL muscle samples were obtained from nine (n = 9) RAC and nine (n = 9) CON carcasses. Mitochondrial proteome was analyzed using two-dimensional electrophoresis, and the digital gel images were analyzed. The protein spots exhibiting more than 1.5-fold intensity differences (P &lt; 0.10) between RAC and CON were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsSeven differentially abundant proteins were identified in the mitochondrial proteome. Three proteins were over-abundant (P &lt; 0.10) in RAC, whereas four spots were over-abundant in CON. The proteins over-abundant in RAC mitochondrial proteome was complement component 1 Q subcomponent-binding protein, very long-chain specific acyl-CoA dehydrogenase, and aconitate hydratase. On the other hand, ATP synthase subunit β, prohibitin, Cytochrome b-c1 complex subunit, and thioredoxin-dependent peroxide reductase were over-abundant in CON samples. The differentially abundant proteins belong to four functional groups; i.e., energy metabolism (ATP synthase subunit β, Cytochrome b-c1 complex subunit 1, and aconitate hydratase), chaperone activity (complement component 1 Q subcomponent-binding protein and prohibitin), antioxidant activity (thioredoxin-dependent peroxide reductase), and lipid metabolism (very long-chain specific acyl-CoA dehydrogenase).ConclusionDietary ractopamine impacts mitochondrial proteome in postmortem beef LL muscle and influences the abundance of proteins involved in cellular metabolism and protective mechanisms. The increased protein synthesis and leanness previously reported in ractopamine-fed cattle may be attributed to the decreased expression of enzymes involved in respiratory electron transport pathways and the increased expression of enzymes involved in lipolysis.

Effect of essential oils on performance, liver abscesses, carcass characteristics and meat quality in feedlot steers

Essential oils (EO) are secondary metabolites derived from plants that have antimicrobial properties which may prevent liver abscesses in feedlot cattle. Seventy-two Angus × Simmental crossbred steers (358 ± 7.6 kg initial BW) were blocked by weight and breed composition and randomly allocated to 3 treatments (4 pens/treatment, 6 steers/pen) to determine the effects of an EO blend or tylosin on performance, liver abscesses, carcass characteristics and meat quality. Treatments were delivered in a premix with dried distillers grains with solubles (DDGS) that were top-dressed daily at a rate of 454 g/steer daily (CON: no additives, TYL: 90 mg/steer daily tylosin, and EO: 1 g/steer daily essential oil blend). The basal diet contained (DM basis) 54% cracked corn, 26% DDGS, 14% corn silage and 6% supplement. Steers were slaughtered at two different time points when a target weight of 624 kg was achieved. Longissimus lumborum muscle samples were taken caudal from the last rib on the right side of each carcass for pH, tenderness, purge and cook loss, and lipid oxidation analyses. Statistical analyses were conducted using the MIXED procedure of SAS. Performance characteristics, including weight, ADG, DMI and gain:feed, did not differ among treatments (P ≥ 0.54). Similarly, no differences were observed in carcass characteristics (P ≥ 0.19). Steers fed EO tended to have an increased prevalence of liver abscesses in the A category (P = 0.10) as compared to CON and TYL. Purge loss was decreased (P = 0.02) for EO steaks compared to CON and TYL, but there were no differences in cook loss, Warner-Bratzler shear force, pH or lipid oxidation among treatments (P ≥ 0.32). In conclusion, an EO blend or tylosin in the diet of finishing steers did not affect growth performance or carcass characteristics, and little difference was observed in liver abscess incidence or meat quality attributes.

Ractopamine-induced changes in the proteome of post-mortem beef &lt;i&gt;longissimus lumborum&lt;/i&gt; muscle

Ractopamine is a beta-adrenergic agonist that is approved for use in beef cattle, pigs and turkeys as a repartitioning agent to increase lean muscle deposition and decrease lipogenesis. Although the effects of dietary ractopamine on the proteome profile of post-mortem pork muscles have been examined, its influence on beef muscle proteome has not been studied. Therefore, the objective of this study was to examine the effect of ractopamine on the proteome profile of post-mortem beef longissimus lumborum (LL) muscle. LL muscle samples were obtained from the carcasses of six (n = 6) steers fed ractopamine (RAC; 400 mg ractopamine hydrochloride for 28 days) and six (n = 6) steers fed no ractopamine (CON). The muscle proteome was analysed using two-dimensional gel electrophoresis and tandem mass spectrometry. Five differentially abundant spots were identified, and all the spots were over-abundant in RAC. The identified proteins were involved in muscle structure development (F-actin-capping protein subunit beta-2; PDZ and LIM domain protein-3), chaperone activity (heat shock protein beta-1), oxygen transport (myoglobin), and glycolysis (L-lactate dehydrogenase A chain). These results suggested that dietary ractopamine could influence the abundance of enzymes associated with muscle development and muscle fibre type shift in beef LL muscle. Keywords: growth promotants, meat quality, proteomics

Ractopamine-Induced Changes in the Mitochondrial Proteome of Postmortem Beef Longissimus Lumborum

ObjectivesRactopamine is a β-adrenergic agonist approved as growth promotant in beef cattle, and it increases muscle deposition while limiting fat deposition. Dietary ractopamine causes a muscle fiber shift in cattle, and the biochemistry of mitochondria in postmortem beef skeletal muscles is influenced by fiber type. Therefore, dietary ractopamine may potentially affect mitochondrial functionality. Nonetheless, the influence of ractopamine on beef skeletal muscle mitochondrial proteome has not been evaluated. Therefore, the objective of this study was to examine the effects of ractopamine on mitochondrial proteome of postmortem longissimus lumborum (LL) from beef cattle.Materials and MethodsPen-housed crossbred steers were fed either a corn-based basal diet (CON) or a diet top-dressed with Optaflexx 45 (Elanco Animal Health) to provide 400 mg of ractopamine hydrochloride/steer per day (RAC). Ractopamine was fed the last 28 d prior to the harvest. The animals were harvested, and carcasses were chilled for 24 h. The LL muscle samples were obtained from nine (n = 9) RAC and nine (n = 9) CON carcasses. Mitochondrial proteome was analyzed using two-dimensional electrophoresis, and the digital gel images were analyzed. The protein spots exhibiting more than 1.5-fold intensity differences (P < 0.10) between RAC and CON were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsSeven differentially abundant proteins were identified in the mitochondrial proteome. Three proteins were over-abundant (P < 0.10) in RAC, whereas four spots were over-abundant in CON. The proteins over-abundant in RAC mitochondrial proteome was complement component 1 Q subcomponent-binding protein, very long-chain specific acyl-CoA dehydrogenase, and aconitate hydratase. On the other hand, ATP synthase subunit β, prohibitin, Cytochrome b-c1 complex subunit, and thioredoxin-dependent peroxide reductase were over-abundant in CON samples. The differentially abundant proteins belong to four functional groups; i.e., energy metabolism (ATP synthase subunit β, Cytochrome b-c1 complex subunit 1, and aconitate hydratase), chaperone activity (complement component 1 Q subcomponent-binding protein and prohibitin), antioxidant activity (thioredoxin-dependent peroxide reductase), and lipid metabolism (very long-chain specific acyl-CoA dehydrogenase).ConclusionDietary ractopamine impacts mitochondrial proteome in postmortem beef LL muscle and influences the abundance of proteins involved in cellular metabolism and protective mechanisms. The increased protein synthesis and leanness previously reported in ractopamine-fed cattle may be attributed to the decreased expression of enzymes involved in respiratory electron transport pathways and the increased expression of enzymes involved in lipolysis.

Supranutritional Supplementation of Vitamin E Influences the Abundance of Antioxidant Proteins in Postmortem Longissimus Lumborum from Heifers

ObjectivesVitamin E is a lipid-soluble antioxidant that can inhibit lipid oxidation and improve beef color stability. The effect of vitamin E on fresh beef color, from the standpoint of lipid oxidation-induced myoglobin oxidation, have been extensively studied. However, the influence of vitamin E on sarcoplasmic proteome profile of beef skeletal muscles is yet to be investigated. Therefore, the objective of this study was to examine the effect of dietary vitamin E on sarcoplasmic proteome of postmortem beef longissimus lumborum (LL) muscle.Materials and MethodsCrossbred heifers, managed with a GrowSafe feeding system, were fed ad libitum corn-based diet containing either no supplemental (CONT) or 1000 IU vitamin E/heifer per day (VITE) for 89 d. The animals were harvested, and carcasses were chilled. The LL muscle samples were obtained from the carcasses of nine (n = 9) VITE and nine (n = 9) CONT heifers 24 h postmortem. The muscle samples were individually vacuum-packaged and frozen at –80°C for proteome analysis. Sarcoplasmic proteome was analyzed using two-dimensional electrophoresis, employing immobilized pH gradient strips (pH 3–10; 17 cm) in the first dimension and 12% sodium dodecyl sulfate polyacrylamide gel electrophoresis in the second dimension. The gels were scanned, and the digital gel images were analyzed. The protein spots exhibiting more than 1.5-fold intensity differences (P < 0.10) between VITE and CONT were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsFive differentially abundant spots were identified using mass spectrometry, and all the spots were over-abundant in CONT. The proteins in the differentially abundant spots were antioxidant proteins (thioredoxin-dependent peroxide reductase, peroxiredoxin-6, and serum albumin) and glycolytic enzymes (β-enolase and triosephosphate isomerase). The antioxidant proteins minimize oxidation of lipids and proteins in muscle matrix, whereas the glycolytic enzymes generate NADPH, which helps maintain the antioxidant proteins in their reduced forms.ConclusionThe strong antioxidant protection offered by vitamin E could have possibly led to less expression of antioxidant proteins as well as glycolytic enzymes that generate antioxidant metabolites in the VITE group, whereas the lack of such protection in CONT group may have led to increased expression of these proteins in the skeletal muscles.

Diets based on plants from Brazilian Caatinga altering ruminal parameters, microbial community and meat fatty acids of Santa Inês lambs

Strategies for the sustainable intensification of ruminant production suggest breeding animals adapted to the environment in which they live using local fodders to maximize efficient ruminal fermentation. The purpose of this study was to explore the effects of using Orbignya phalerata (Babassu) and Combretum leprosum (Mofumbo) leaves in ruminal short chain fatty acids (SCFA) and microbial community, as well as finishing performance, carcass characteristics and meat fatty acid profile of Santa Inês hair lambs. The experimental treatments were diets with 50:50 forage:concentrate ratios, using the leaves of the experimental plants as a 33g/100g of dry matter (DM) replacement of Cynodon dactylon (Tifton-85) hay, with three groups: Control (no hay replacement), Babassu and Mofumbo. Twenty-four Santa Inês lambs (body weight=20.0±5.2kg) were used in a randomized experimental design with eight repetitions (5 males and 3 female) per treatment. Ruminal fluid samples of each animal were collected to determine SCFA and microbial community. The male animals were evaluated for finishing performance and carcass characteristics while longissimus lumborum muscle samples were used for determination of fatty acid profile. Interaction between treatment and sex was observed for total SCFA (P<0.05). Treatment affected (P<0.05) propionate, isobutyric, isovaleric and valeric fatty acids. Mofumbo showed a greater relative abundance of rumen fungi and Ruminococcus flavefaciens, and lower Archaea. There was no difference between treatments (P>0.05) for finishing performance and carcass characteristics but meat fatty acid characteristics were affected by treatments. A redundancy analysis based on microbial abundance profile demonstrated two clusters, one cluster with Babassu and Control treatments, and other cluster with Mofumbo, with some variables associated to dissimilarity between clusters. These results indicated that the inclusion of these plants in lamb diets affects ruminal short chain fatty acids and microbial population, without compromising the production potential, carcass characteristics and meat fatty acid profile.

Ractopamine Influences Muscle Proteome Profile of Postmortem Beef Longissimus Lumborum

ObjectivesRactopamine is a β-adrenergic agonist approved for use in cattle and pigs as a repartitioning agent to increase muscle deposition and potentially limit fat deposition. While the effects of ractopamine on proteome profile of postmortem pork muscles have been examined recently, its influence on beef muscle proteome has not been evaluated. Therefore, the objective of this study was to examine the effects of ractopamine on muscle proteome of postmortem longissimus lumborum (LL) from beef cattle.Materials and MethodsCrossbred steers housed in pens were fed either a corn-based basal diet (CON) or a diet top-dressed with Optaflexx 45 (Elanco Animal Health) to provide 400 mg of ractopamine hydrochloride/steer per day (RAC). Ractopamine was fed the last 28 d before slaughter. Steers were harvested, and carcasses were chilled. The LL muscle samples were obtained from the carcasses of 9 (n = 9) RAC and CON steers 24 h postmortem. The muscle samples were individually vacuum-packaged and frozen at –80°C for proteome analysis. Whole-muscle proteome was analyzed using 2-dimensional electrophoresis, and the digital gel images were analyzed. The protein spots exhibiting more than 1.5-fold intensity differences (P < 0.10) between RAC and CON were subjected to in-gel tryptic digestion and were identified by tandem mass spectrometry.ResultsFive differentially abundant protein spots identified were of greater (P < 0.10) abundance in LL samples from RAC compared to those from CON. The proteins identified were F-actin-capping protein subunit β2, PDZ and Lim domain protein-3, heat shock protein β-1, myoglobin, and L-lactate dehydrogenase A chain. The differentially abundant proteins belong to 4 functional groups; i.e., skeletal muscle organization (F-actin-capping protein subunit β2, and PDZ and LIM domain protein-3), chaperone activity (heat shock protein β-1), oxygen transportation (myoglobin), and energy metabolism (L-lactate dehydrogenase A chain).The over-abundance of F-actin-capping protein subunit β2 as well as PDZ and LIM domain protein-3 in RAC may be attributed to the increase in myofibrillar protein synthesis and increase in muscle mass as a result of ractopamine feeding. Heat shock protein β-1 is a chaperone that protects muscle proteins, and its increased abundance in RAC compared to CON may be due to the increased muscle protein synthesis. The over-abundance of myoglobin could possibly result from the increased oxygen consumption due to additional muscle mass accretion in RAC compared to CON, whereas the increased levels of L-lactate dehydrogenase A chain in RAC could potentially be due to the shift of muscle fiber type.ConclusionThe findings indicated that feeding ractopamine to steers influences the abundance of proteins involved in skeletal muscle organization, chaperone activity, oxygen transportation, and energy metabolism in postmortem beef LL muscle.

Net lactate accumulation and low buffering capacity explain low ultimate pH in the longissimus lumborum of AMPKγ3R200Q mutant pigs

Postmortem lactate accumulation in skeletal muscle is linearly associated with the extent of pH decline. Yet, pigs harboring the AMPKγ3R200Q mutation produce meat with similar lactate levels to that of wild-type pigs but have a lower ultimate pH. We hypothesized that lower initial lactate levels and (or) lower buffering capacity in muscle of these pigs may help explain this discrepancy. Longissimus lumborum muscle samples were harvested at 0 and 1440min postmortem from AMPKγ3R200Q and wild-type pigs. As expected, AMPKγ3R200Q muscle exhibited a lower ultimate pH but similar lactate levels to that of wild-type pigs at 1440min postmortem. However, the total net lactate produced postmortem was greater in the AMPKγ3R200Q muscle due to lower initial lactate levels at 0min postmortem. Buffering capacity measured over the pH range of 5.5–7.0 was also lower in AMPKγ3R200Q muscle. Greater net lactate accumulation postmortem (i.e., glycolytic flux) coupled with a lower buffering capacity explains the lower ultimate pH of meat from AMPKγ3R200Q pigs.

Efeito da casca de mandioca sobre a qualidade da carne e parâmetros ruminais de ovinos

This work evaluated different forms of processing of cassava peel for use in sheep feeding and its effects upon composition, meat quality, lipid profile and rumen morphometrics. A total of 20 weaned Santa Ines male sheeps, with initial weight 19.02±0.21 kg, were used. The fac-torial scheme utilized was a completely randomized design, with 4 treatments (A: supplement with dehydrated cassava peel ground, using a 12 mm sieve; B: supplement with dehydrated cassava peel ground using a 5 mm sieve; C: supplement with ensiled cassava peel; D: supplement with hydrolyzed cassava peel). Each animal was considered a replication, with 5 replications per treatment. The were reared in semiexten-sive system, on Brachiaria decumbens pasture. Treatments were supplied as supplement at proportion of 1.5 % of live weight (ratio roughage: concentrate of 62.5:37.5 %), amounts of food were adjusted, every week, according to the animals weight. The experiment lasted 84 days, including 14 days for adaptation to the diets. Animals were slaughtered at 30.72±1.46 kg final weight; after slaughter and cooling (24 hours at ±2 oC), samples of Longissimus lumborum muscle were collected to carry out the physicochemical analyses, and establish lipid profile. There were no significant differences for ashes, moisture and protein. The fed supplement with hydrolyzed cassava peel, presented higher values for ether extract. The fatty acid profile was not affected by processing type of cassava peels. The histological evaluation revealed alteration in the rumen epithelium and area of the omasal lamina, with higher values for coarsely ground cassava peel supplement. No influence of the supplements was found for physicochemical composition. The different supplements were not enough to alter the meat quality parameters, however, hydrolyzed cassava peel brought about increased accumulation of lipids in the muscle.

Muscle fibre characteristics of a native pig breed longissimus lumborum muscle

The aim of this study was to investigate the histochemical parameters of muscle fibre in a Spanish autochthonous pig breed. Due to its fatty meat and high prolificacy, this pork is revered among local consumers. However, the aforementioned breed has become endangered. A total of 11 native pigs (Black Canary Pig) were evaluated. Longissimus lumborum muscle samples were collected in order to evaluate contractile and metabolic characteristics of the varying fibre types by histochemical staining techniques (nicotinamide adenine dinucleotide tetrazolium reductase [NADH-TR] and myosin adenosine triphosphatase activity [mATPase]). Cross-sectional area, diameter and percentage of the fibres were calculated. The oxidative fibre percentage was elevated (33.63%) which in turn can improve the colour, tenderness and juiciness of the meat, hence the glycolytic fibre percentage being moderate (66.37%). The size of three fibre types was higher than the values provided by other pig breeds. A higher percentage of IIB fibres is a disadvantage because these fibres cannot store a high percentage of intrafibrilar fat which could be linked to myopathic process. In conclusion, this autochthonous pig breed could potentially produce red meat and high quality, dry-cured pork products thanks to its remarkably high percentage of oxidative fibres, which naturally possess a greater capacity to store intramuscular fat.

Growth, Carcass and Meat Quality of Casertana, Italian Large White and Duroc x (Landrace x Italian Large White) Pigs Reared Outdoors

To compare growth, skeletal development, carcass traits and meat quality of different genotypes, 10 Casertana (CT), 10 Italian Large White (LW) and 10 Duroc x (Landrace x Italian Large White) (DU) crosses, barrows of 90 days of age, were allotted to the same outdoor rearing and feeding conditions. Live weight was recorded and average daily gain (ADG) was calculated. At slaughter (330-day-old) dressing and lean percentages were determined; backfat thickness and loin eye depth were measured. Carcasses were dissected into commercial cuts. Water holding capacity, pH and colour (45 min and 24 h post-mortem) were measured. Longissimus lumborum muscle samples were collected for cholesterol, α-tochopherol and intramuscular collagen (IMC) analyses. CT compared to DU and LW had the lowest growth rate and skeletal development.Casertana showed higher backfat thickness, lower lean cut/fatty cut ratio and less lean meat (P<0.05). Loin eye depth differed among genotypes with LW>DU>CT (P<0.05). CT showed higher red colour of the meat than DU and LW (P<0.05). CT compared to LW had the highest hydroxylysylpiridinoline (HLP) crosslink concentration and HLP/IMC ratio, and a lower IMC amount (P<0.05). Casertana pigs produced meat that could be tougher than that from the improved breed, but more acceptable from the technological point of view.At eleven months of age bone weight, length and diameter were clearly genetic type-related; differently, the bone maturity was similar among the genotypes studied.

Genetic variants in a lipid regulatory pathway as potential tools for improving the nutritional quality of grass‐fed beef

The aim of this study was to evaluate the effect of genetic variants on candidate genes corresponding to the sterol recognition element-binding protein-1 (SREBP-1) signaling pathway and stearoyl-CoA desaturases (SCD1 and SCD5) on muscle fatty acid (FA) composition of Brangus steers fattened on grass. FA profiles were measured on Longissimus lumborum muscle samples using a gas chromatography-flame ionization detection technique. A total of 43 tag single-nucleotide polymorphisms on the SCD1, SCD5, SREBP-1, SCAP, INSIG1, INSIG2, MBTPS1, MBTPS2, and SRPR genes were genotyped on 246 steers to perform a marker-trait association study. To evaluate the influence of the Indicine breed in the composite breed, additional groups of 48 Angus, 18 Hereford, 75 Hereford x Angus, and 36 Limousin x Hereford-Angus steers were also genotyped. To perform the association analysis, FA data were grouped according to the number of carbon atoms and/or number of double bonds (i.e. SFA, MUFA, PUFA, etc.). In addition, different indexes that reflect the activity of FA desaturase and elongase enzymes were calculated. SCD1 markers significantly affected C14:1/(C14:0+C14:1) and C18:1/(C18:0+C18:1) indexes, whereas one SNP in SCD5 was correlated with the C16:1/(C16:0+C16:1) index. Polymorphisms in the signal recognition particle receptor (SRPR) gene were associated with all the estimated desaturase indexes. Because the evaluated markers showed no effect on total lipid content of beef, this work supports the potential utilization of these markers for the improvement of grass-fed beef without undesirable side effects.