Longissimus Dorsi Samples Research Articles

The influence of feed additive “Activo” on the content of total lipids and their classes profile in liver and skeletal muscles of pigs

With an increase in meat consumption the requirements for its quality also rise. As pork is the second most popular meat in the world, producers of this product are trying to improve its quality. The purpose of our research was to determine the effect of the feed additive “Activo”, containing essential oils of cinnamon, rosemary and oregano, and chili pepper extract, on the total lipids content and their individual class profile in liver and skeletal muscles of pigs. The study was conducted on pigs of the large white breed, weighing 70 kg, divided on two groups, according to the piglets-analogues principle, which then were divided into control and experimental groups. Pigs of both groups received standard feed (SF) intended for this age group. Pigs of the experimental group received the feed additive “Activo” in an amount of 0.1 kg/t of feed in addition to SF. The duration period of experiment was 40 days. Samples of liver, longissimus dorsi, and latissimus dorsi muscle tissues were used as material for the study. The total lipid content was determined using gravimetric method, and individual lipid profile using thin-layer chromatography on silica gel plates. The study has shown that the total lipid content in the liver, long and broad back muscles of pigs of the experimental group was 1.66 and 1.95 (P≤0.001) and 1.26 (P≤0.05) times higher, respectively, than in animals of the control group. The relative cholesterol esters content in the liver lipids of the experimental group pigs was 1.9 (P≤0.001) times higher than in the control group. Instead, in the latissimus dorsi muscle, a lower content of triacylglycerols and a higher content of unesterified fatty acids (P≤0.05), esterified cholesterol (P≤0.05), and especially phospholipids (P≤0.001) were admitted. It was determined significant decrease of unesterified cholesterol content in the latissimus dorsi muscle (P≤0.001) and increase of phospholipids content (P≤0.001) under the effect of the researched feed additive.

Identification of key lncRNAs and mRNAs in muscle development pathways of Tan sheep

The study aimed to identify the long noncoding RNA (lncRNA) responsible for regulating muscle development in Tan sheep. RNA-seq analysis was conducted on longissimus dorsi samples from 1-day-old and 60-day-old Tan sheep to investigate the molecular processes involved in muscle development. A total of 5517 lncRNAs and 2885 mRNAs were found to be differentially expressed in the 60-day-old Tan sheep. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis revealed that these differentially expressed lncRNAs and mRNAs were linked to pathways crucial for muscle development, such as MAPK, cAMP, and calcium-mediated signaling pathways. Key genes like CDKN1A, MAPK14, TGFB1, MEF2C, MYOD1, and CD53 were identified as significant players in muscle development. The study validated the RNA-seq results through RT-qPCR, confirming the consistency of expression levels of differentially expressed lncRNAs and mRNAs. These findings indicate that lncRNA-mRNA networks produce a remarked effect on modulating muscle development in Tan sheep, such as lncRNAs (MSTRG.12808.1/MSTRG.22662.3/MSTRG.18310.1) and mRNAs (MSTRG.10027/MSTRG.10029/MSTRG.10258/MSTRG.11011/MSTRG.10354), laying the groundwork for future research in this area.

204 Changes in DNA methylation 5 days after exposure to acute heat stress in beef cattle skeletal muscle

Abstract The objective of this study was to investigate the effects of acute heat stress on the skeletal muscle epigenome using reduced representation bisulfite sequencing (RRBS). March-born crossbred (5/8 Red Angus, 3/8 Simmental) steers (n = 14; average body weight = 308.7 kg) were exposed to heat stress (HS) conditions of 35°C + 35% relative humidity (Temperature Humidity Index = 81) for 12h/d for 2 d (48 h). Longissimus dorsi samples were collected via biopsy and flash-frozen in liquid nitrogen immediately following the HS period at 48 h and from the contralateral longissimus dorsi 5 d later. DNA was isolated and underwent RRBS using 150 bp paired-end reads at an achieved average depth of 15.3 million reads/sample. Reads were trimmed and mapped to a bisulfite-converted bovine genome (ARSUCD1.2). Methylation calls were extracted and used to identify differentially methylated regions (DMRs) with methylkit in R comparing samples collected 5 d post-HS to those taken immediately post-48 h of HS. Differentially methylated regions (1,000 bp) had q < 0.05 and at least a 15% difference in methylation. There were 1,015 DMRs in genes. Hypomethylated DMRs 5 d post-HS included IGF1R, IGF2, IGF2BP1, IGFBP4, IGF2R, IKBKB, and IL34. Hypermethylated DMRs 5 d post-HS included FGF5, FGFR1, and FGFR3. There were 81 DMRs in putative promoter regions (2000 bp 5’ of a gene). MYLK2, SIGIRR, and 25 other genes had hypomethylated promoter regions. Genes that contained DMRs were used as input for DAVID to explore KEGG pathways. Enriched pathways (P < 0.1) included multiple hormone pathways, MAPK, PI3K-Akt, HIF-1, and VEGF. Hypomethylation of IGF-related genes and hypermethylation of FGF-related genes suggests impaired growth capacity post-HS, as does the enrichment of MAPK and PI3K-Akt pathways. Hypomethylation of SIGIRR’s promoter region, IL34 and IKBKB, indicates enhanced anti-inflammatory activity given their known regulation of inflammatory cytokine production. This, coupled with enrichment of the HIF-1 and VEGF pathways, suggests regulatory dampening of HS-induced oxidative stress. These findings reveal key regulatory changes in muscle growth, inflammatory response, and oxidative stress activity for cattle recovering from acute HS. Previous cattle skeletal muscle RNA studies predicted that HS altered metabolism, inflammation, and oxidative stress pathways, similar to the methylation results of this study. Overall, evidence suggests growth dysregulation, which may help explain observed HS-induced poor growth due to HS, as well as subsequent anti-inflammatory activity during recovery from HS.

Screening for Genes Related to Meat Production Traits in Duroc × Bama Xiang Crossbred Pigs by Whole Transcriptome Sequencing.

The meat production traits of pigs are influenced by the expression regulation of multiple gene types, including mRNAs, miRNAs, and lncRNAs. To study the differences in meat production traits at the transcriptional level among individuals with different growth rates, the longissimus dorsi samples from eight Duroc × Bama Xiang F2 crossbred pigs with a fast growth rate (high gTroup) or a slow growth rate (low group) were selected to perform whole transcriptome sequencing and ceRNA regulatory network construction. This study first analyzed the differences in physiological and biochemical indicators, muscle histological characteristics, and muscle fiber types. A total of 248 mRNAs, 25 miRNAs, and 432 lncRNAs were identified as differentially expressed by whole transcriptome sequencing. Key genes that may influence meat production traits include MTMR14, PPP1R3A, PYGM, PGAM2, MYH1, and MYH7. The ceRNA regulatory network map showed that ENSSSCG00000042061-ssc-mir-208b-MYH7, ENSSSCG00000042223-ssc-mir-146a-MTMR14, ENSSSCG00000045539-ssc-mir-9-3-MYH1, and ENSSSCG00000047852-ssc-mir-103-1-PPP1R3A may be the key factors affecting meat production traits through their regulatory relationships. This study provides valuable insights into the molecular mechanisms underlying porcine muscle development and can aid in improving meat production traits.

Supplementation with dimethylglycine sodium salt improves lipid metabolism disorder in intrauterine growth-retarded pigs

This study aims to elucidate the mechanism of lipid metabolism disorder in intrauterine growth retardation (IUGR) pigs and the potential alleviating effects of dimethylglycine sodium salt (DMG-Na). A total of 60 male newborn piglets were selected for this study. Within each litter, one normal birth weight (NBW) male piglet (1.53 ± 0.04 kg) and two IUGR male piglets (0.76 ± 0.06 kg) were chosen based on their birth weight. The piglets were divided into three groups for the study: NBW pigs received a PBS gavage and a common basal diet (NBW-C group), IUGR pigs received the same PBS gavage and common basal diet (IUGR-C group), and IUGR pigs received a 70-mg DMG-Na gavage along with a common basal diet supplemented with 0.1% DMG-Na (IUGR-D group). At 150 d of age, all piglets underwent euthanasia by exsanguination following electrical stunning, after which plasma, liver, and longissimus dorsi (LM) samples were promptly collected. The IUGR-D group demonstrated improvements in plasma parameters (P < 0.05), with lower triglyceride and free fatty acid (FFA) values, and hormone levels (P < 0.05), with lower growth hormone, insulin, and homeostasis model assessment of insulin resistance values. Restoration of lipid metabolism was observed (P < 0.05), with lower triglyceride and FFA, and higher hepatic lipase and total lipase values in the liver, and lower triglyceride and FFA values in the LM. Mitochondrial ETC complexes showed increased levels (P < 0.05), including higher complex III values in the liver, and higher complex I, complex III, and complex V values in the LM. Enhanced levels of energy metabolites were noted (P < 0.05), with higher NAD+, NAD+/NADH, adenosine triphosphate, and mtDNA values, and lower NADH values in the liver and LM. Additionally, meat quality parameters showed improvement (P < 0.05), with higher pH 24 h and a∗ values, and lower drip loss 48 h, L∗, and b∗ values. The expressions of lipid metabolism and mitochondrial function-related genes and proteins were upregulated (P < 0.05) compared to the IUGR-C group. In conclusion, it was indicated that IUGR pigs experienced lipid metabolism disorders and diminished performance. However, supplementation with DMG-Na showed promise in mitigating these adverse physiological effects by safeguarding body tissues and modulating energy metabolism.

The Effects of Different Zilpaterol Hydrochloride Feed Supplements and Extended Aging Periods on the Meat Quality of Feedlot Bulls

This study researched the effects of two commercially available zilpaterol hydrochloride (ZH) β-adrenergic agonists, denoted as ZH-A and ZH-B, on the meat quality characteristics of typical South African feedlot bulls (taurine × indicus composites), over extended aging periods of up to 120 days. The effects of ZH were studied to address concerns about the possible adverse effects of ZH on beef quality following extended aging, which typically occurs during the exportation of beef by boat. The completely randomized control study consisted of 3 homogenous experimental groups, with 3 replicates per treatment and 50 bulls per replicate = 450 animals. Treatments were a negative control (CT) with no ZH supplementation added to the basal diet or a basal diet supplemented with either zilpaterol hydrochloride A (ZH-A) or zilpaterol hydrochloride B (ZH-B), both at 105 g ZH/ton, fed from the first day of the finishing period (D0) for 30 days. Subsamples were collected from 38 random carcasses from each treatment for proximate analysis and meat quality analysis using Longissimus dorsi samples. ZH supplementation decreased meat tenderness (Warner–Bratzler shear force values (WBSF)) of bulls fed ZH-A or ZH-B, compared to those fed the CT diet (p &lt; 0.05; η2 = 0.24). The WBSF values of both ZH treatments were about 0.5–0.8 kg higher during the aging periods compared to the CT, but ZH did not affect post-mortem meat aging or meat quality characteristics differently compared to the CT. Post-mortem aging per se influenced all meat quality characteristics investigated (p &lt; 0.001; η2 &gt; 0.30), showing improvements in WBSF, a decrease in meat colour and an increase in drip and cooking losses. L*-values increased from 3 to 56 days of aging and then decreased to day 120 (p &lt; 0.001; η2 = 032). Chroma values decreased from day 3 to day 120 (p &lt; 0.001; η2 = 0.50). Hue° decreased from day 3 to day 7 and stabilized until day 120 (p &lt; 0.001; η2 = 0.40). Moisture and cooking loss (CL) increased to 56 days and then decreased to 120 days.

Effects of dietary minerals deficiency and supplementation on different parts of muscle minerals content in grazing Mongolian sheep.

The objective of this study was to investigate the impact of dietary deficiency and supplementation of calcium, zinc, copper, cobalt, manganese or selenium on minerals content in the longissimus dorsi (LD), biceps femoris (BF) and triceps brachii (TB) of grazing Mongolian sheep. We randomly divided 98 sheep into 7 treatment groups and fed them specific diets for 60 days: a total mineral nutrition diet (LCG), a calcium deficiency diet (LCa), a zinc deficiency diet (LZn), a copper deficiency diet (LCu), a cobalt deficiency diet (LCo), a manganese deficiency diet (LMn) and a selenium deficiency diet (LSe). Then 7 sheep from each group were slaughtered and samples of LD, BF and TB were collected for mineral content analysis. The remaining sheep in each group were subsequently fed specific diets for an additional 41 days: a total mineral nutrition diet (SCG), a calcium supplementation diet (SCa), a zinc supplementation diet (SZn), a copper supplementation diet (SCu), a cobalt supplementation diet (SCo), a manganese supplementation diet (SMn) and a selenium supplementation diet (SSe). Afterward, all sheep were slaughtered, and muscle samples were collected and analyzed. Significant findings emerged that LCa decreased sulfur (S) content in BF and increased Ca content in LD and BF, while SCa increased S and Ca content in BF and TB, respectively (P < 0.05). LZn decreased Zn, S, and potassium (K) content in LD and BF, while SZn increased Zn and S content in LD and BF, respectively (P < 0.05). LCu decreased Cu and iron (Fe) content in LD and TB, while SCu increased Fe content in TB (P < 0.05). LCo decreased phosphorus, S, K, Ca, Mn, Fe, Cu, and Zn content in LD (P < 0.05). LMn decreased Mn content and increased K content in TB, while SMn decreased K content in BF and TB (P < 0.05). LSe and SSe decreased and increased Se content in LD, BF, and TB, respectively (P < 0.05). Dietary mineral levels have varying effects on lamb meat minerals content. It is important to ensure an adequate intake of minerals in the diet to enhance the mineral nutrition of lamb meat.

Enhancing Physicochemical Characteristics of Donkey Meat through High‐Voltage Electrostatic Stimulation during Acid Excretion

To investigate the impact of high‐voltage electrostatic stimulation on the quality of donkey meat, ten 30‐month‐old Dezhou donkeys (each weighing 250 ± 50 kg) were selected. Following slaughter, longissimus dorsi (LD) samples from both left and right carcasses were collected. The control group refrigerated the right muscle in a 0–4°C refrigerator for normal acid excretion. Meanwhile, the high‐voltage electrostatic group subjected the left muscle to high‐voltage electrostatic stimulation (30000 V) for 60 s before refrigerating it in the same conditions for acid excretion. The study showed that at the 1st, 6th, and 24th h of acid excretion, the high‐voltage electrostatic group exhibited significantly lower pH levels than the control group (P&lt;0.05). Furthermore, a∗ values in the high‐voltage electrostatic group showed an increasing trend relative to the control group at the 6th and 24th h of acid excretion (P = 0.0751, P = 0.0860). With increasing acid excretion time, both treatment groups displayed increased PV and TBARS values. At 48 and 72 h, the PV values in the high‐voltage electrostatic group were significantly lower than those in the control group (P &lt; 0.05). As acid excretion time increased, T‐AOC, SOD, and GSH‐Px in both groups decreased. However, the high‐voltage electrostatic group consistently exhibited higher antioxidant enzyme activity than the control group at all time points. SOD and GSH‐Px activity in the high‐voltage electrostatic group showed an increasing trend at 48 h of acid excretion (P = 0.0838, P = 0.0860). At 72nd h of acid excretion, the shear force of donkey meat in the high‐voltage electrostatic group was significantly lower than that in the ordinary treatment group (P &lt; 0.05). With increasing acid excretion time, the MFI of both treatment groups gradually increased. In particular, at the 1st and 48th h of acid excretion, the MFI of the high‐voltage electrostatic group was significantly higher than that of the ordinary treatment group (P &lt; 0.05). Following high‐voltage electrostatic stimulation, ultrastructure images of donkey meat at 6 and 72 h revealed numerous contractions and stretching bands. Therefore, this stimulation significantly improved the tenderness of donkey meat, reduced the oxidation rate of donkey meat, and improved the quality of donkey meat.

Color Stability During Retail Display Differs Among Muscles in Pork

The objectives of this study were to determine differences in color stability among pork muscles and whether changes in color measurements for longissimus dorsi (LD) were related to changes for triceps brachii (TB) or psoas major (PM). The LD, TB, and PM from 20 pigs were aged in vacuum packages for 21 d, then fabricated into 3 chops per muscle. All chops from a single muscle were overwrapped, displayed for 5 d under constant lighting, and evaluated daily for instrumental color, myoglobin forms, and subjective visual discoloration. Chops were removed on day 1, 3, or 5 to measure oxygen consumption (OC) and metmyoglobin reducing activity (MRA). Data were analyzed using the MIXED procedure of SAS as repeated measures. Pearson correlation coefficients were determined using the CORR procedure. Over the 5-d display period, TB and PM chops had greater changes in a*, b*, chroma, 630/580 nm ratio, deoxymyoglobin, and oxymyoglobin compared to LD chops (display time×muscle interaction P≤0.01), but TB and PM did not differ from each other (P≥0.07). Conversely, LD had decreased OC and increased MRA on each display day compared to TB and PM (P&amp;lt;0.01). Using 20% discolored on day 5 of display as a threshold for acceptability, 85% of LD samples were considered acceptable whereas only 5% and 20% of TB and PM samples were considered acceptable, respectively. Changes in LD were correlated with TB and PM changes for redness (0.51≤r≤0.55; P≤0.02), and they trended toward a correlation with changes in TB and PM 630/580 nm ratio and hue angle (0.39≤r≤0.63). Chops from TB and PM were less color stable during display, but LD changes were not consistently correlated with changes in other muscles.

Wild boar captured in a large corral-style trap or hunted: preliminary comparison of meat quality traits.

The management and numerical control of wild boars mainly depend on hunting practices, even if other alternative strategies such as the use of traps and cages can be adopted. There is little information available on the quality of captured wild boar meat. The aim of this study was to evaluate the meat quality of wild boars captured with a large corral-style trap compared to still hunting and collective hunting methods. Longissimus dorsi samples were collected from 60 wild boars, 20 of which were obtained by trapping, 20 by still hunting, and 20 by collective hunting. The animals considered were 32 males and 28 females, weighing between 42 and 68 kg. Muscle pH has been recorded at 1, 24, and 48 hours post-mortem. Furthermore, after 24 hours, color, drip loss, cooking loss, and Warner-Bratzler shear force were also evaluated. Trapping with large enclosures such as corral-style traps, if properly managed, does not seem to adversely affect the quality traits of wild boar meat, which were found to be like those obtained by the still hunting method.

Effects of the F94L myostatin gene mutation in beef × dairy crossed cattle on strip loin steak dimensionality, shear force, and sensory attributes.

Carcasses (n = 115) from steers resulting from the mating of four Limousin × Angus sires heterozygous for the F94L myostatin mutation to Jersey, Jersey × Holstein, and Holstein dams were utilized to evaluate the effects of one copy of the F94L allele on strip loin dimensionality, Warner-Bratzler shear force and slice shear force, and sensory panel ratings. In Phase I of a two-phase study, 57 carcasses from two sires were utilized to obtain samples of longissimus dorsi (LD), psoas major (PM), gluteus medius (GM), semitendinosus (ST), serratus ventralis (SV), triceps brachii (TB), and biceps femoris (BF) muscles, which were vacuum packaged, aged until 10 days postmortem, and frozen. Frozen strip loins were cut into 14 2.5-cm-thick steaks each, and individual strip loin steaks were imaged at a fixed height on a gridded background and processed through image analysis software. In Phase II, to obtain a greater power of test for LD palatability attributes, 58 additional carcasses from 3 sires were utilized to obtain LD samples only for sensory panel and shear force analysis. Cooked steak sensory attributes evaluated by trained panelists were tenderness, juiciness, beef flavor, browned flavor, roasted flavor, umami flavor, metallic flavor, fat-like flavor, buttery flavor, sour flavor, oxidized flavor, and liver-like flavor. In strip loin steaks from carcasses with one F94L allele, LD muscle area was larger in steaks 4, 5, 7, 8, and 9, and steaks 1, 6, 7, and 9 were less angular than those from carcasses with no F94L allele (P < 0.05). Of the seven muscles observed, there were no shear force differences between F94L genotypes (P > 0.20). F94L genotype did not affect sensory panel ratings of LD and GM steaks (P > 0.07). Cooked ST steaks from carcasses with one F94L rated lower in fat-like flavor compared to those from carcasses with no F94L allele (P = 0.035). Cooked PM steaks from carcasses with one F94L allele rated lower in juiciness, fat-like flavor, buttery flavor, and umami flavor compared to those with no copies of the F94L (P < 0.04). In summary, one copy of the F94L allele utilized in beef × dairy cross steers improved strip loin steak dimensionality, did not affect cooked steak tenderness across seven muscles, and decreased fat-associated flavors in the PM and ST. Use of F94L homozygous terminal beef sires would be an easily implemented strategy for dairy producers to improve steak portion size and shape in carcasses from non-replacement calves.

Effect of different doses of cholecalciferol and calcidiol on meat quality parameters and skeletal muscle transcriptome profiles in swine

Skeletal muscle tissue is one of the potential targets for vitamin D actions. There are indications that vitamin D supplementation to swine has a positive effect on meat quality. However, these issues need further study, especially in terms of response to the use of different forms of vitamin D. We carried out a multi-purpose study to compare the effects of cholecalciferol and calcidiol on meat quality and muscle tissue transcriptome. Meat quality assessment and gene expression analysis were performed on longissimus dorsi samples collected from swine fed grower/finisher diets containing 2000 IU cholecalciferol/1500 IU cholecalciferol per kg (n = 8), 3000 IU cholecalciferol/2500 IU cholecalciferol per kg (n = 10), 2000 IU cholecalciferol +1000 IU calcidiol/1500 IU cholecaliferol +1000 IU calcidiol per kg (n = 8), and 2000 IU calcidiol/1500 IU calcidiol per kg (n = 8). The results suggest that increasing the dose of cholecalciferol and using calcidiol in the diet of finishers may improve meat texture parameters (shear force P = 0,014, toughness P = 0,048, cohesiveness P = 0,017, resilience P = 0,002). Shear force (68.46 N–51.42 N) and toughness (145.85 N–114.52 N) decreased the most under the effect of increasing cholecalciferol dosage. In turn, cohesiveness (0.60 N–0.65 N) and resilience (0.23 N–0.28 N) increased most strongly under the use of cholecalciferol+calcidiol. Moreover, the results indicate no significant effect of increasing cholecalciferol dose and use calcidiol in the swine diet on muscle tissue transcriptome.

MiR-381-3p Inhibits Intramuscular Fat Deposition through Targeting FABP3 by ceRNA Regulatory Network.

Simple SummaryIntramuscular fat (IMF) deposition is an important determinant of pork quality and a complex process facilitated by non-coding ceRNAs. Emerging evidence suggests that IMF deposition is a complex process facilitated and associated with non-coding RNAs, such as microRNAs and long non-coding RNA (lncRNA). In our study, whole-transcriptome sequencing analysis was performed using longissimus dorsi samples of six low and high IMF Berkshire × Anqing Sixwhite crossbred pigs. Differentially expressed (DE) lncRNAs, miRNAs, and mRNAs, were screened and constructed 34 competing endogenous RNA (ceRNA). Following weighted gene co-expression network analysis, only one ceRNA, lncRNA4789/miR-381-3p/FABP3, that showed similar DE trend in longissimus dorsi tissue was retained. Furthermore, dual-luciferase reporter assays further indicated that FABP3 was a direct, functional target of miR-381-3p while overexpressed lncRNA4789 attenuated the effect of miR-381-3p on FABP3 by sponging miR-381-3p. Cell function verification experiment demonstrated that miR-381-3p suppressed IMF deposition by inhibiting preadipocyte cell differentiation and lipid droplet deposition via the suppression of FABP3 expression in the peroxisome proliferator-activated receptor signalling pathway, whereas lncRNA4789 rescued FABP3 expression by sponging miR-381-3p. Our study may aid in identifying novel molecular markers for its optimization in IMF which is of importance in breeding for improving pork quality.Intramuscular fat (IMF) deposition is an important determinant of pork quality and a complex process facilitated by non-coding ceRNAs. In this study, 52 Berkshire × Anqing Sixwhite crossbred pigs were slaughtered to measure eight carcass and pork quality traits. Whole-transcriptome sequencing analysis was performed using longissimus dorsi samples of six low- and high-IMF samples; 34 ceRNA networks, based on 881, 394, 158 differentially expressed (DE) lncRNAs, miRNAs, and mRNAs, were constructed. Following weighted gene co-expression network analysis between the low and high IMF, only one ceRNA, lncRNA4789/miR-381-3p/FABP3, that showed similar DE trend in longissimus dorsi tissue was retained. Dual-luciferase reporter assays further indicated that FABP3 was a direct, functional target of miR-381-3p, where miR-381-3p overexpression inhibited the mRNA and protein expression of FABP3. In addition, overexpressed lncRNA4789 attenuated the effect of miR-381-3p on FABP3 by sponging miR-381-3p. Cell function verification experiment demonstrated that miR-381-3p suppressed IMF deposition by inhibiting preadipocyte cell differentiation and lipid droplet deposition via the suppression of FABP3 expression in the peroxisome proliferator-activated receptor signalling pathway, whereas lncRNA4789 rescued FABP3 expression by sponging miR-381-3p. Our study may aid in identifying novel molecular markers for its optimization in IMF which is of importance in breeding for improving pork quality.

Gestational heat stress alters skeletal muscle gene expression profiles and vascularity in fetal pigs in a sexually dimorphic manner

BackgroundThere is evidence that sow heat stress (HS) during gestation affects fetal development with implications for impaired muscle growth. We have previously demonstrated that maternal HS during early to mid-gestation compromised muscle fibre hyperplasia in developing fetal pigs. Thus, we hypothesised these phenotypic changes are associated with a change in expression of genes regulating fetal skeletal muscle development and metabolism. To test this, at d 60 of gestation, RNA sequencing and immunohistochemistry were performed on fetal longissimus dorsi (LD) muscle biopsies collected from pregnant gilts that had experienced either thermoneutral control (CON, 20 °C, n = 7 gilts, 18 LD samples) or controlled HS (cyclic 28 to 33 °C, n = 8 gilts, 23 LD samples) conditions for 3 weeks.ResultsA total of 282 genes were differentially expressed between the HS and CON groups in female LD muscles (false discovery rate (FDR) ≤ 0.05), whereas no differentially expressed genes were detected in male LD muscles between the two groups (FDR > 0.05). Gestational HS increased the expression of genes associated with transcription corepressor activity, adipogenesis cascades, negative regulation of angiogenesis and pro-inflammatory signalling in female LD muscles. Immunohistochemical analyses revealed a decreased muscle vascularity density in fetuses from HS group for both sexes compared to those from the CON group (P = 0.004).ConclusionsThese results reveal gilt HS during early to mid-gestation altered gene expression profiles in fetal LD muscles in a sexually dimorphic manner. The molecular responses, including transcription and angiogenesis repressions and enhanced adipogenesis cascades, were exclusively observed in females. However, the associated reductions in muscle vascularity were observed independently of sexes. Collectively this may indicate female fetal pigs are more adaptive to gestational HS in terms of gene expression changes, and/or there may be sexually dimorphic differences with respect to the timing of muscle molecular responses to gestational HS.

Effect of dietary protein level and fasting length on enzymatic activity of cathepsin B in live muscle and in meat from heavy finishing pigs

To evaluate the effect of dietary protein level (13.0% and 9.5% CP) and duration of fasting on the enzymatic activity of cathepsin B in live muscle and pig, 44 fattening pigs weighing 138 ± 9 kg were reared to slaughter (171 ± 9 kg). The feed allowance was set at 3.2 kg/day. Two weeks prior to slaughter, subjects on each diet were randomly assigned to one of two different fasting treatments (no fasting or 48 h fasting). After this treatment, an individual longissimus dorsi(LD) muscle sample was taken from each pig by biopsy at the level of the third lumbar vertebra and frozen in liquid nitrogen until analysis. Then, the subjects within each diet × fasting interaction were assigned to different fasting times before slaughter (4 or 28 or 52 h). One day after slaughter, LD and semimembranous muscle (SM) samples were taken from each carcass, kept at 4 °C for 24 h and then frozen in liquid nitrogen. The activity of cathepsin B was measured in muscle homogenates by colorimetric method. Dietary CP did not affect cathepsin activity in LD obtained in vivo and daily live weight gain up to slaughter. Compared to the absence of fasting, a cathepsin activity greater than 18% in LD was observed after 48 h of fasting (P < 0.01). Cathepsin activity in LD and SM sampled after slaughter was not affected by dietary protein level and fasting 2 weeks prior to slaughter. Compared with 28 h fasting, feeding exclusion for 52 h prior to slaughter increased cathepsin activity in the LD and SM muscles by 18% (P < 0.05) and 12% (P = 0.07) respectively. The preslaughter fasting length had no effect on fresh meat quality parameters (pH at 1 and 24 h post mortem, colour, drip losses, cooking losses).

Thermal conductivity factor for beef of NOR and DFD grades at the subcryoscopic temperatures

Thermal conductivity factor and specific isobaric heat capacity of food products are currently the most important parameters in the development of mathematical models for food freezing and thawing and in improving production technology. There is significant variance among the existing experimental data for the thermal conductivity factor in meat. Most of the modern calculated relationships are based on the nutritional approach, which favorably differs by the ability to calculate the thermophysical characteristics of any food products. However, the calculation error at the subcryoscopic temperatures may be 15% to 20%. The development of superchilling as a way of storing meat requires high accuracy of freezing time calculation, including vacuumpacked boneless meat. In the presented article, the authors investigated hydrogen index, cryoscopic temperature, frozen moisture proportion and thermal conductivity factor for beef M. longissimus dorsi samples of NOR and DFD grades. It was found that DFD beef is characterized by 10% to 12% higher values of thermal conductivity factor in comparison with NOR grade. Using the method of regression analysis, the authors developed empirical relationships for calculating the thermal conductivity factor of meat depending on its temperature and pH level. Unlike cryoscopic temperature and frozen moisture proportion, pH is easy to measure and may be easily used on a conveyor belt for more accurate assessment of meat thermophysical properties. With an increase in pH from 5.3 to 7, an increase in cryoscopic temperature is observed from minus 0.94 °C to minus 0.72 °C. It has been shown that one of the factors for the higher cryoscopic temperature and higher pH level of DFD beef is higher water-holding capacity with less strongly bound moisture.

526 Late-Breaking: Poor Maternal Diet Alters the Muscle Proteome at Mid-gestation in Sheep

Abstract Maternal diet during gestation can negatively impact fetal development and postnatal growth and body composition. We hypothesized that poor maternal nutrition during gestation would alter protein expression in muscle at day 90 of gestation in sheep. Pregnant ewes (n = 24) were fed a control, restricted, or over-fed diet (100, 60, or 140% of NRC requirements for total digestible nutrients, respectively; n = 8 per treatment) starting at day 30 of gestation. At day 90 of gestation, fetal longissimus dorsi samples were collected (CON, RES, and OVER, respectively). Sarcoplasmic proteins were trypsin digested and subjected to multiplexed, label-based quantitative mass spectrometry analysis integrating Tandem Mass Tags. Differential expression of proteins was identified via two statistical techniques: ANOVA followed by Tukey’s HSD post-hoc tests, and regularized regression via elastic net. Significance was set at P &amp;lt; 0.05. Over-represented pathways containing differentially expressed proteins were identified by Reactome and included metabolism of proteins, immune system, cellular response to stress/external stimuli, developmental biology, and infectious disease. Within these pathways, 26S proteasome non-ATPase regulatory subunit (PSMD) 1, PSMD6, and PSMD14, components of the 26 S proteasome, were reduced 6 to 10% in OVER relative to CON offspring. Proteins involved in elongation and initiation, including eukaryotic initiation factor (EIF) 2 subunit 3, EIF 4 gamma 2, and EIF 3 subunit B were reduced 8 to 15% in OVER relative to CON offspring. Mitogen-activated protein kinase (MAPK) 1 and dual-specificity MAPK kinase (MEKK) 1 were increased by 12% in RES relative to OVER and CON offspring. Together, these data indicate that protein degradation and synthesis are altered in mid-gestation muscle development in OVER offspring, and that cell signaling related to cell proliferation is affected in RES offspring. These changes may contribute to the phenotypic and metabolic changes observed during fetal development and postnatal growth.

Effect of bis-glycinate bound zinc or zinc sulfate on zinc metabolism in growing lambs.

To assess the efficacy of bis-glycinate bound Zn, 36 crossbred wethers (34 ± 2 kg) were sorted by body weight into three groups and stagger started on a Zn-deficient diet (18 mg Zn/kg dry matter [DM]; 22.5% neutral detergent fiber [NDF]) for 45 d prior to a 15-d metabolism period (10 d adaptation and 5 d collection). On day 46, lambs were randomly assigned to dietary treatments (four lambs treatment−1group−1): no supplemental Zn (CON) or 15 mg supplemental Zn/kg DM (ZINC) as Zn sulfate (ZS) or bis-glycinate (GLY; Plexomin Zn, Phytobiotics). Blood was collected from all lambs on days 1, 44, 56, and 61. Liver, jejunum, and longissimus dorsi samples were collected after euthanasia on day 61. Gene expression was determined via quantitative real-time polymerase chain reaction. Data were analyzed using ProcMixed of SAS (experimental unit = lamb; fixed effects = treatment, group, and breed) and contrast statements assessed the effects of supplemental Zn concentration (ZINC vs. CON) and source (GLY vs. ZS). After 15 d of Zn supplementation, plasma Zn concentrations were greater for ZINC vs. CON and GLY vs. ZS (P ≤ 0.01); tissue Zn concentrations were unaffected (P ≥ 0.27). Liver Cu concentrations were lesser for ZINC vs. CON (P = 0.03). Longissimus dorsi Mn concentrations were greater for ZINC vs. CON (P = 0.05) and tended to be lesser for GLY vs. ZS (P = 0.09). Digestibility of DM, organic matter (OM), and NDF was lesser for ZINC vs. CON (P ≤ 0.05); acid detergent fiber digestibility tended to be greater for GLY vs. ZS (P = 0.06). Nitrogen retention (g/d) tended to be greater for GLY vs. ZS (P = 0.10), and N apparent absorption was lesser for ZINC vs. CON (P = 0.02). Zinc intake, fecal output, retention, and apparent absorption were greater for ZINC vs. CON (P ≤ 0.01). Apparent absorption of Zn was −5.1%, 12.8%, and 15.0% for CON, ZS, and GLY, respectively. Nitrogen and Zn retention and apparent absorption were not correlated for CON (P ≥ 0.14) but were positively correlated for ZINC (retention: P = 0.02, r = 0.52; apparent absorption: P < 0.01, r = 0.73). Intestinal expression of Zn transporter ZIP4 was lesser for ZINC vs. CON (P = 0.02). Liver expression of metallothionein-1 (MT1) tended to be greater for GLY vs. ZS (P = 0.07). Although Zn apparent absorption did not differ between sources (P = 0.71), differences in post-absorptive metabolism may be responsible for greater plasma Zn concentrations and liver MT1 expression for GLY-supplemented lambs, suggesting improved bioavailability of GLY relative to ZS.

Integrated microRNA-mRNA analysis reveals the roles of microRNAs in the muscle fat metabolism of Yanbian cattle.

Fat deposition is an important economic trait in farm animals. However, it is difficult to genetically improve intramuscular fat deposition via trait-based cattle breeding. The main objectives of this study were to analyze the factors about beef flavor, and to detect functional microRNA (miRNA, miR) associated with intramuscular fat deposition in Yanbian cattle. Longissimus dorsi samples from six steers were separated into high- and low-fat groups (n=3 each) based on the marbling score, and transcriptomic analysis was performed using miRNA sequencing. A total of 33 miRNAs and 38 genes were found to be differentially expressed in the high- and low-fat groups. Quantitative real-time polymerase chain reaction was performed to validate the sequencing results. Integrated miRNA-mRNA analysis revealed that miRNA-associated target genes were primarily associated with skeletal muscle development. However, some of the miRNAs (miR-424 etc.) and genes (ATF3 etc.) were also associated with fat metabolism. A targeted relationship between miR-22-3p and the WFIKKN2 gene and its involvement in adipocyte differentiation were confirmed experimentally. The study findings may provide potential candidate molecular targets for the selection of cattle with improved meat quality.

The Meat Quality and Sensory Characteristics of Turkish Native Sheep Genotypes

Some meat quality and sensory characteristics were determined of Kıvırcık (n=10), Eşme Kıvırcık (n=10), Karya (n=8) and Çine Çaparı (n=9) lambs in this research. Carcass divided into two parts along the spine and the three different type of muscle samples were taken from the between 8th and 9th vertebrae, 12th and 13th vertebrae and leg part of the left side of the carcasses. Drip loss, cooking loss and shear force values of these muscles were identified. Additionally, pH0, pH24, color, fatty acid composition and sensory properties were determined in M. Longissimus dorsi samples. When muscle types are evaluated separately were a statistically significant factor in terms of dripping and cooking loss and shear force. While the highest dripping loss were reported in M. Longissimus dorsi (3.72%), the highest cooking loss were reported in M. Longissimus thoracis (22.67%) and the highest shear force were reported in M. semitendinosus (4.38 kg). Genotype and muscle interaction were found to be highly significant for only cooking loss. The analysis results for fatty acids indicated that there was an important difference between Kıvırcık, Eşme Kıvırcık, Karya and Çine Çaparı on C10:0, C12:0, C14:0, C15:0, C16:0, tC18:1, CLA, tC18:3, C20:1, C22:0 fatty acids in the study. Genotypes showed no effect to SFA (Saturated fatty acids), MUFA (Monounsaturated fatty acids), PUFA (Polyunsaturated fatty acids) and P/S ratio parameters. Karya lambs performed higher for odor and tenderness, and Kıvırcık lambs showed a higher score for juiciness, flavor and total acceptability in sensory evaluation.