Cattle Muscle Research Articles

Genome-Wide Association Integrating a Transcriptomic Meta-Analysis Suggests That Genes Related to Fat Deposition and Muscle Development Are Closely Associated with Growth in Huaxi Cattle

Growth traits are among the most important economic phenotypes targeted in the genetic improvement of beef cattle. To understand the genetic basis of growth traits in Huaxi cattle, we performed a genome-wide association study (GWAS) on body weight, eye muscle area, and back fat thickness across five developmental stages in a population of 202 Huaxi cattle. Additionally, publicly available RNA-seq data from the longissimus dorsi muscle of both young and adult cattle were analyzed to identify key genes and genetic markers associated with growth in Huaxi cattle. In total, 7.19 million high-quality variant loci (SNPs and INDELs) were identified across all samples. In the GWAS, the three multilocus models (FarmCPU, MLMM, and BLINK) outperformed the conventional single-locus models (CMLM, GLM, and MLM). Consequently, GWAS analysis was conducted using multilocus models, which identified 99 variant loci significantly associated with growth traits and annotated a total of 83 candidate genes (CDGs). Additionally, 23 of the 83 CDGs overlapped with significantly differentially expressed genes identified from public RNA-seq datasets of longissimus dorsi muscle between young and adult cattle. Furthermore, gene functional enrichment (KEGG and GO) analyses revealed that over 30% of the pathways and GO terms were associated with muscle development and fat deposition, crucial factors for beef production. Specifically, key genes identified included MGLL, SGMS1, SNX29 and AKAP6, which are implicated in lipid metabolism, adipogenesis, and muscle growth. In summary, this study provides new insights into the genetic mechanisms underlying growth traits in Huaxi cattle and presents promising markers for future breeding improvements.

Identification of cis-sQTL demonstrates genetic associations and functional implications of inflammatory processes in Nelore cattle muscle tissue.

This study aimed to identify splicing quantitative trait loci (cis-sQTL) in Nelore cattle muscle tissue and explore the involvement of spliced genes (sGenes) in immune system-related biological processes. Genotypic data from 80 intact male Nelore cattle were obtained using SNP-Chip technology, while RNA-Seq analysis was performed to measure gene expression levels, enabling the integration of genomic and transcriptomic datasets. The normalized expression levels of spliced transcripts were associated with single nucleotide polymorphisms (SNPs) through an analysis of variance using an additive linear model with the MatrixEQTL package. A permutation analysis then assessed the significance of the best SNPs for each spliced transcript. Functional enrichment analysis was performed on the sGenes to investigate their roles in the immune system. In total, 3,187 variants were linked to 3,202 spliced transcripts, with 83 sGenes involved in immune system processes. Of these, 31 sGenes were enriched for five transcription factors. Most cis-sQTL effects were found in intronic regions, with 27 sQTL variants associated with disease susceptibility and resistance in cattle. Key sGenes identified, such as GSDMA, NLRP6, CASP6, GZMA, CASP4, CASP1, TREM2, NLRP1, and NAIP, were related to inflammasome formation and pyroptosis. Additionally, genes like PIDD1, OPTN, NFKBIB, STAT1, TNIP3, and TREM2 were involved in regulating the NF-kB pathway. These findings lay the groundwork for breeding disease-resistant cattle and enhance our understanding of genetic mechanisms in immune responses.

Effects of dietary oregano essential oil supplementation on carcass traits, muscle fiber structure, oxidative stability, meat quality, and regulatory mechanisms in Holstein steers.

Dietary supplementation for beef cattle, using natural plant extracts, such as oregano essential oil (OEO), has proven effective in enhancing growth performance, beef production quantity and quality, and ensuring food safety. However, the precise mechanisms underlying these effects remain unclear. This study investigated the impact of OEO on carcass traits, muscle fiber structure, meat quality, oxidative status, flavor compounds, and gene regulatory mechanisms in the longissimus thoracis (LT) muscles of beef cattle. Eighteen steers were randomly assigned to two groups (n = 9 per group) and fed either a control diet (CK) or the same diet supplemented with 20 g of OEO per head per day for 300 days. Oregano essential oil supplementation improved the body weight, carcass weight, meat production, area and diameter of fiber, ether extract, and water-holding power of muscle. Increasing catalase (CAT), peroxidases (POD), glutathione peroxidase (GSH-Px) and by decreasing lipid droplets (LDs) reduced muscle lipid oxidation. However, the color (L*, a*, b*, C* and H°) and the flavor compounds of muscle were affected adversely by OEO. The transcriptome and metabolome indicated the OEO group enriched fat synthesis, proteo-metabolism, antioxidants, and growth significantly. Five key genes (SH2B2, CD209, LOC504773, C1QC, and HMOX) and ten downregulated metabolites (deoxyguanosine, d-melezitose, maltotriose, raffinose, melatonin, quinic acid, orotic acid, hydrocinnamic acid, 2-methylsuccinic acid, and pyridoxal 5'-phosphate) were identified as key biomarkers. These interacted to positively influence the growth, oxidative status, and meat quality of steers positively. These findings suggest that OEO, as a natural bioactive compound, can serve as an additive for beef cattle, with a daily dose of 20 g per steer improving growth and meat quality, although it may affect muscle color and flavor negatively. © 2025 Society of Chemical Industry.

Comparative analysis of the whole transcriptome landscapes of muscle and adipose tissue in Qinchuan beef cattle

BackgroundMuscle and adipose tissue are the most critical indicators of beef quality, and their development and function are regulated by noncoding RNAs (ncRNAs). However, the differential regulatory mechanisms of ncRNAs in muscle and adipose tissue remain unclear.ResultsIn this study, 2,343 differentially expressed mRNAs (DEMs), 235 differentially expressed lncRNAs (DELs), 95 differentially expressed circRNAs (DECs) and 54 differentially expressed miRNAs (DEmiRs) were identified in longissimus dorsi muscle (LD), subcutaneous fat (SF) and perirenal fat (VF) in Qinchuan beef cattle. The results of functional enrichment analysis showed that DEMs, DELs, DECs and DEmiRs were enriched in biological processes related to development and function of muscle and fat deposition, including skeletal muscle contraction, muscle organ development, PPAR signaling pathway, fatty acid metabolism and MAPK signaling pathway. Based on the competing endogenous RNA (ceRNA) regulatory mechanism, we constructed a lncRNA/circRNA-miRNA-mRNA network consisting of 6 circRNAs, 5 lncRNAs, 6 miRNAs and 27 mRNAs. Among them, 55 ceRNA axes were involved, including circRNA12990 - bta-miR-133a_L-1R + 1 - MYO6/ZEB2, circRNA2893/MSTRG.28538.1/MSTRG.11613.4 - pma-miR-145-5p_R + 2 - EYA4 and MSTRG.26982.1 - bta-let-7e_R + 1 - RBM40.ConclusionsThis study identified a group of differentially expressed mRNAs, lncRNAs, circRNAs and miRNAs between muscle and adipose tissue and constructed a potential ceRNA regulatory network, which may serve as a foundation for studying the differential regulatory roles of ncRNAs in the development and function of muscle and adipose tissue.

Replace part of regenerative rice silage feed with whole cottonseed enhances growth performance and nutrient digestibility via regulating gH/IGF axis in beef cattle

This work was designed to assess the impacts of whole cottonseed (WCs) on growth performance, nutrient digestion, GH /IGF-1 axis, and meat quality in beef cattle. Twenty-four healthy male simmental cattle (18 months old and 370.5 ± 12.5 kg) were arbitrarily classified into two groups (n=12 per group): Control group (without WCs) and WCs replaced group (part of regenerative rice silage was replaced with WCs). The dry matter intake (DMI) was declined(P < 0.01), while the average daily gain (ADG) was increased(P < 0.05), therefore the feed conversion ratio (FCR) was lower (P < 0.05) in WCs replaced group. Beef cattle consuming WCs had a higher digestibility of total gastrointestinal nutrients (P < 0.01 or P < 0.05). The growth hormone receptor (GHR), insulin-like growth factor 1 (IGF-1), and insulin-like growth factor 1 receptor (IGF-1R) mRNA amounts were all enhanced (P < 0.05) in liver, longissimus dorsi muscle, and semitendinosus muscle of beef cattle after feeding WCs relative to control group. The mRNA amounts of phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), mammalian target of rapamycin (mTOR), and ribosomal protein S6 kinase beta-1 (S6K1) and the protein phosphorylation levels of Akt、mTOR, and S6K1 were all markedly enhanced (P < 0.05 or P < 0.01) in liver, longissimus dorsi muscle, and semitendinosus muscle for WCs replacement. The shear force and cooking loss values having somewhat raised(P < 0.05) for WCs replacement. Altogether, WCs improves the growth performance and nutrient digestibility via regulating GH/IGF axis in beef cattle, and has negative effects on meat quality.

DNA Imprinting and Differentially Expressed Genes in Longissimus thoracis Muscle of Bos indicus Submitted to Early Weaning Management.

Background/Objectives: Early weaning management followed by energy supplementation can lead to metabolic alterations in the calf that exert long-term effects on the animal's health and performance. It is believed that the main molecular basis underlying these metabolic adaptations are epigenetic mechanisms that regulate, activate, or silence genes at different stages of development and/or in response to different environmental stimuli. However, little is known about postnatal metabolic programming in Bos indicus. Therefore, this study aimed to compare the DNA methylation profile of Nellore animals submitted to conventional and early weaning and to correlate the findings with genes differentially expressed in the Longissimus thoracis skeletal muscle of Bos indicus cattle. Methods: For this, we used Reduced Representation Bisulfite Sequencing (RRBS) and RNA-Sequencing techniques to prospect differentially methylated genes (DMGs). Results: A total of 481 differentially methylated regions were identified, with 52% (250) being hypermethylated and 48% (231) hypomethylated. Functional enrichment analysis of 53 differentially methylated and differentially expressed genes was performed. The main enriched terms and pathways were associated with 3'-5'-cyclic adenosine monophosphate (cAMP) signaling, which presents the upregulated adenylate cyclase 3 (ADCY3) gene and significatively hypomethylated in the promoter region. Alterations in cAMP signaling are involved in numerous processes, many of them related to lipid metabolism. The relative differential expression of key genes of this pathway demonstrates the relationship between cAMP signaling and de novo lipogenesis. Conclusions: These findings suggest an important role of postnatal metabolic programming through DNA methylation mechanisms in determining fat deposition in beef.

Cis-eQTL analysis reveals genes involved in biological processes of the immune system in Nelore cattle

The combination of transcriptional profiling and genotype data analyses enables the identification of genetic variants that may affect gene expression (eQTL – expression quantitative trait loci). This study aimed to identify cis-eQTL in Nellore cattle muscle tissue and determine their biological processes related to the immune system and involved eGenes. Genotypic data (SNP-Chip) and gene expression data (RNA-Seq) from a commercial population of 80 Nellore animals were evaluated. For the cis-eQTL identification, association tests were conducted for all variants near the gene (cis variants), followed by permutation tests to correct for multiple comparisons. Our analyses revealed 828 top cis-eQTL related to 1,062 genes of which most of these variants were in intronic and intergenic regions. The eQTLs rs109525554, rs109589165, rs110192253, rs133127698, rs137742430, rs41803313, rs43366333, and rs43711242 were associated with susceptibility and resistance to infections in cattle. Additionally, interferon family eGenes, such as IFNT3, IFN-TAU, IFNK, FYN, and IFNW1, and endothelial leukocyte migration, such as PRKCG and CXCL10 were found. These eGene families were linked to biological processes of innate and adaptive immune responses and associated with somatic cell scores in cattle, respectively. Our results may have implications for selecting desirable resistance traits in animals bred for production and highlight the importance of studying genetic variants involved in quantitative traits to improve our understanding of genetic mechanisms underlying gene expression regulation of adaptive traits in cattle.

Increased rumen Prevotella enhances BCAA synthesis, leading to synergistically increased skeletal muscle in myostatin-knockout cattle

Myostatin (MSTN) is a negative regulator of muscle growth, and its relationship with the gut microbiota is not well understood. In this study, we observed increase muscle area and branched-chain amino acids (BCAAs), an energy source of muscle, in myostatin knockout (MSTN-KO) cattle. To explore the link between increased BCAAs and rumen microbiota, we performed metagenomic sequencing, metabolome analysis of rumen fluid, and muscle transcriptomics. MSTN-KO cattle showed a significant increase in the phylum Bacteroidota (formerly Bacteroidetes), particularly the genus Prevotella (P = 3.12e-04). Within this genus, Prevotella_sp._CAG:732, Prevotella_sp._MSX73, and Prevotella_sp._MA2016 showed significant upregulation of genes related to BCAA synthesis. Functional enrichment analysis indicated enrichment of BCAA synthesis-related pathways in both rumen metagenomes and metabolomes. Additionally, muscle transcriptomics indicated enrichment in muscle fiber and amino acid metabolism, with upregulation of solute carrier family genes, enhancing BCAA transport. These findings suggest that elevated rumen Prevotella in MSTN-KO cattle, combined with MSTN deletion, synergistically improves muscle growth through enhanced BCAA synthesis and transport.

Alternative polyadenylation landscape of longissimus dorsi muscle with high and low intramuscular fat content in cattle.

Intramuscular fat content is one of the most important factors affecting beef quality. However, the role of alternative polyadenylation (APA) in intramuscular fat deposition remains unclear. We compared APA events in muscle samples from high and low intramuscular fat (IMF) cattle, based on RNA-seq data. A total of 363 significant APAs were identified. Notably, the number of shortened 3'UTR events exceeded the number of lengthened 3'UTR events, and genes associated with shortened 3'UTR events were enriched in fatty acid metabolism-related pathways. Most APA events had alternative 3'UTR (aUTR) lengths of 200 to 300bp. As the 3'UTR lengthened, the aUTR also lengthened (R2 = 0.79). These findings indicate that genes with longer 3'UTRs are more likely to be regulated by APA in the muscle of cattle with high IMF. To determine whether the identified APA events drove alterations in the expression of fat deposition-related genes, we analyzed the relationship between APA events and differentially expressed genes and identified several genes critical for fat deposition (e.g., PFKL and SLC1A5). Since miRNAs usually bind to the 3'UTR region of protein-coding genes and affect gene expression, we constructed an miRNA-APA network to detect several key miRNAs that may regulate fat deposition. We identified 10 important miRNAs that affect changes in IMF content, which may be gained (gained miRNA-binding sites) or lost (lost miRNA-binding sites) owing to 187 differential APA events. Our study characterized the APA profiles of cattle with high and low intramuscular fat content and provided further insights into the relationship between APA, miRNA, and fat deposition.

Development of a physiologically based pharmacokinetic model for flunixin in cattle and swine following dermal exposure.

Flunixin meglumine is a nonsteroidal anti-inflammatory drug (NSAID). Banamine Transdermal is a pour-on formulation of flunixin approved for pain control in beef and dairy cattle, but not for calves and some classes of dairy cattle or swine. Violative flunixin residues in edible tissues in cattle and swine have been reported and are usually attributed to non-compliant drug use or failure to observe an appropriate withdrawal time. This project aimed to develop a physiologically based pharmacokinetic (PBPK) model for flunixin in cattle and swine to predict withdrawal intervals (WDI) after exposures to different therapeutic regimens of Banamine Transdermal. Due to the lack of comprehensive skin physiological data in cattle, the model was initially developed for swine and then adapted for cattle. Monte Carlo simulation was employed for population variability analysis. The model predicted WDIs were rounded to 1 and 2 d for liver and muscle in cattle, respectively, under FDA tolerance levels, while under EU maximum residue limits, the WDIs were rounded to 1, 3, 2, and 2 d for liver, kidney, muscle, and fat, respectively, following a labeled single transdermal 3.3 mg/kg dose in cattle. The model was converted into a user-friendly interactive PBPK (iPBPK) interface. This study reports the first transdermal absorption model for drugs in cattle. This iPBPK model provides a scientifically based tool for the prediction of WDIs in cattle and swine administered with flunixin in an extra-label manner, especially by the transdermal route.

Development of a Method for the Determination of Rifaximin and Rifampicin Residues in Foods of Animal Origin.

Rifaximin and rifampicin are good broad-spectrum antimicrobials. The irrational use of antimicrobial drugs in veterinary clinics could threaten public health and food safety. It is necessary to develop a reliable detection method of the residue for enhancing the rational supervision of the use of such drugs, reducing and slowing down the generation of bacterial resistance, and promoting animal food safety and human health. So, this study developed an LC-MS/MS method for the detection of rifaximin and rifampicin residues in animal-origin foods. The residual rifaximin and rifampicin of homogenized test materials were extracted with acetonitrile-dichloromethane solution or acetonitrile in the presence of anhydrous sodium sulfate and vitamin C, purified by dispersible solid phase extraction, determined by LC-MS/MS, and quantified by the internal standard method. The specificity, sensitivity, matrix effect, accuracy, and precision of the method were investigated in the edible tissues of cattle, swine, or chicken. In addition, the stability of the standard stock solution and the standard working solution was also investigated. The method was suitable for the muscle, liver, kidney, fat, milk, and eggs of cattle, swine, or chicken, as well as fish and shrimp. The specificity of the method was good, and the detection of the analytes was not affected by different matrices. Both the LOD and LOQ of the two analytes were 5 μg/kg and 10 μg/kg, respectively. The results of matrix effects in each tissue were in the range of 80-120%; there were no significant matrix effects. The average accuracy of rifaximin and rifampicin in different foodstuffs of animal origin was between 80% and 120%, and the method precision was below 20% (RSD). The proposed method showed good performance for determination, which could be employed for the extraction, purification, and detection of residual rifaximin and rifampicin in edible animal tissues. The pretreatment procedure of tissue samples was simple and feasible. The method was highly specific, stable, reliable, and with high sensitivity, accuracy, and precision, which met the requirements of quantitative detection of veterinary drug residues.

Real-time monitoring of cattle (Bos taurus) tissue using a novel point-of-care (POC) polymerase spiral reaction (PSR) colorimetric assay

Adulteration of cattle meat with other species raises critical public health concerns, as existing detection methods lack sensitivity, specificity and practicality. We address this gap by introducing a novel Point-of-Care (POC) polymerase spiral reaction (PSR) assay. This rapid, on-site tool enables highly specific and sensitive identification of cattle tissue, even in resource-limited settings. This innovation paves the way for improved food safety and consumer protection. The cattle-specific PSR assay employs COX3 gene-targeting primers and a chromogenic indicator triad (HNB, Malachite Green and Phenol Red) for rapid visual detection. Cross-amplification absence with other meats (buffalo, sheep, goat and pig) and concordance with SYBR Green I and agarose gel electrophoresis confirm specificity. PSR at 62 °C for 60 minutes exhibits a 100 fg detection limit and identifies 0.1 % meat admixing. Efficacy is demonstrated across a diverse range of cattle meat samples, blind samples and processed cattle muscle samples. Compatibility with both conventional (snap chill) and commercial DNA extraction kits enables on-site analysis within 90 minutes, facilitating rapid field sample analysis.

PSX-3 Transcriptional response to an alternative diet on liver, muscle, and rumen of beef cattle

Abstract Feed cost represents a major economic determinant within cattle production, amounting to an estimated 75% of the total variable costs. Consequently, comprehensive approaches such as optimizing feed utilization through alternative feed sources, alongside the selection of feed-efficient animals, are of great significance. Here, we investigate the effect of two diets, traditional corn-grain fed and alternative by-product based, on 14 phenotypes related to feed, methane emission and production efficiency and on multi-tissue transcriptomics data from liver, muscle, and rumen wall, derived from Nellore bulls (n = 52), 26 on each diet. To this end, diets were contrasted at the level of phenotype, gene expression, and gene-phenotype network connectivity. As regards the phenotypic level, at a P-value &amp;lt; 0.05, significant differences were found in favor of the alternative diet for average daily weight gain at finishing, dry matter intake at finishing, methane emission, carcass yield and subcutaneous fat thickness at the rib-eye muscle area. In terms of the transcriptional level of the 14,776 genes expressed across the examined tissues, we found 487, 484, and 499 genes differentially expressed due to diet in liver, muscle, and rumen, respectively (P-value &amp;lt; 0.01). To explore differentially connected phenotypes across both diet-based networks, we focused on the phenotypes with the largest change in average number of connections within diets and tissues, namely methane emission and carcass yield, highlighting, in particular, gene expression changes involving SREBF2, and revealing the largest differential connectivity in rumen and muscle, respectively. Similarly, from examination of differentially connected genes across diets, the top-ranked most differentially connected regulators within each tissue were MEOX1, PTTG1, and BASP1 in liver, muscle, and rumen, respectively. Changes in gene co-expression patterns suggest activation or suppression of specific biological processes and pathways in response to dietary interventions, consequently impacting the phenotype. The identification of genes that respond differently to diets and their associated phenotypic effects serves as a crucial steppingstone for further investigations, aiming to build upon our discoveries. Ultimately, such advancements hold the promise of improving animal welfare, productivity, and sustainability in livestock farming.

PSVII-7 Putative epigenetic regulating fatty acids content in muscle of Nelore cattle

PSVII-7 Putative epigenetic regulating fatty acids content in muscle of Nelore cattle

Selective and low transfer of pyrrolizidine alkaloids from Jacobaea vulgaris Gaertn. into muscle and liver of dairy cattle, goat and sheep

1,2-unsaturated pyrrolizidine alkaloids and their N-oxides (PA/PANO) are plant toxins that are produced by several hundreds of plant species. Due to the pronounced liver toxicity and carcinogenicity of certain PAs, their presence in food and feed has raised concern. However, since PA-producing weeds cannot generally be prevented on grassland and Senecio species often occur in high densities, the transfer of PAs into muscle and liver of dairy cattle, goat and sheep was determined. In 28-day feeding studies extracts of tansy ragwort (Jacobaea vulgaris Gaertn.) were administered orally in three dose levels per animal species. Of the administered Senecio PAs only jacobine, jaconine and jacoline could be detected in relevant quantities by LC-MS/MS in the muscle and liver tissues of the three animal species. The calculated transfer parameters show a low transfer of total PAs into muscle (transfer factors: 0.0004–0.0009) and liver (transfer factors: 0.0008–0.0030), which is lower than reported for other typical contaminants and residues in the literature. This selective transfer can be explained by the rumen passage, during which the other Senecio PAs are largely and rapidly transformed to fully saturated metabolites. These ruminal metabolites were not detected in muscle and liver. No evidence of bioaccumulation of PAs in muscle and liver was observed.

Identification of several lncRNA-mRNA pairs associated with marbling trait between Nanyang and Angus cattle

BackgroundThe marbling trait of cattle muscles, being a key indicator, played an important role in evaluating beef quality. Two breeds of cattle, namely a high-marbling (Angus) and a low-marbling (Nanyang) one, with their cattle muscles selected as our samples for transcriptome sequencing, were aimed to identify differentially expressed long non-coding RNAs (lncRNAs) and their targets associated with the marbling trait.ResultsTranscriptome sequencing identified 487 and 283 differentially expressed mRNAs and lncRNAs respectively between the high-marbling (Angus) and low-marbling (Nanyang) cattle muscles. Twenty-seven pairs of differentially expressed lncRNAs-mRNAs, including eighteen lncRNAs and eleven target genes, were found to be involved in fat deposition and lipid metabolism. We established a positive correlation between fourteen up-regulated (NONBTAT000849.2, MSTRG.9591.1, NONBTAT031089.1, MSTRG.3720.1, NONBTAT029718.1, NONBTAT004228.2, NONBTAT007494.2, NONBTAT011094.2, NONBTAT015080.2, NONBTAT030943.1, NONBTAT021005.2, NONBTAT021004.2, NONBTAT025985.2, and NONBTAT023845.2) and four down-regulated (NONBTAT000850.2, MSTRG.22188.3, MSTRG.22188.4, and MSTRG.22188.5) lncRNAs and eleven genes related to adiponectin family protein (ADIPOQ), cytochrome P450 family (CYP4V2), 3-hydroxyacyl-CoA dehydratase family (HACD4), kinesin family (KIF5C), lipin family (LPIN2), perilipin family (PLIN1), prostaglandin family (PTGIS), solute carrier family (SLC16A7, SLC2213, and SLCO4C1), and containing a transmembrane domain protein family (VSTM1).ConclusionsThese candidate genes and lncRNAs can be regarded as being responsible for regulating the marbling trait of cattle. lncRNAs along with the variations in intramuscular fat marbling established a foundation for elucidating the genetic basis of high marbling in cattle.

Transcriptional response to an alternative diet on liver, muscle, and rumen of beef cattle

Feed cost represents a major economic determinant within cattle production, amounting to an estimated 75% of the total variable costs. Consequently, comprehensive approaches such as optimizing feed utilization through alternative feed sources, alongside the selection of feed-efficient animals, are of great significance. Here, we investigate the effect of two diets, traditional corn-grain fed and alternative by-product based, on 14 phenotypes related to feed, methane emission and production efficiency and on multi-tissue transcriptomics data from liver, muscle, and rumen wall, derived from 52 Nellore bulls, 26 on each diet. To this end, diets were contrasted at the level of phenotype, gene expression, and gene-phenotype network connectivity. As regards the phenotypic level, at a P value < 0.05, significant differences were found in favour of the alternative diet for average daily weight gain at finishing, dry matter intake at finishing, methane emission, carcass yield and subcutaneous fat thickness at the rib-eye muscle area. In terms of the transcriptional level of the 14,776 genes expressed across the examined tissues, we found 487, 484, and 499 genes differentially expressed due to diet in liver, muscle, and rumen, respectively (P value < 0.01). To explore differentially connected phenotypes across both diet-based networks, we focused on the phenotypes with the largest change in average number of connections within diets and tissues, namely methane emission and carcass yield, highlighting, in particular, gene expression changes involving SREBF2, and revealing the largest differential connectivity in rumen and muscle, respectively. Similarly, from examination of differentially connected genes across diets, the top-ranked most differentially connected regulators within each tissue were MEOX1, PTTG1, and BASP1 in liver, muscle, and rumen, respectively. Changes in gene co-expression patterns suggest activation or suppression of specific biological processes and pathways in response to dietary interventions, consequently impacting the phenotype. The identification of genes that respond differently to diets and their associated phenotypic effects serves as a crucial stepping stone for further investigations, aiming to build upon our discoveries. Ultimately, such advancements hold the promise of improving animal welfare, productivity, and sustainability in livestock farming.

Molecular cloning of TPM3 gene in qinchuan cattle and its effect on myoblast proliferation and differentiation

Tropomyosin 3 (TPM3) plays a significant role as a regulatory protein in muscle contraction, affecting the growth and development of skeletal muscles. Despite its importance, limited research has been conducted to investigate the influence of TPM3 on bovine skeletal muscle development. Therefore, this study revealed the role of TPM3 in bovine myoblast growth and development. This research involved conducting a thorough examination of the Qinchuan cattle TPM3 gene using bioinformatics tools to examine its sequence and structural characteristics. Furthermore, TPM3 expression was evaluated in various bovine tissues and cells using quantitative real-time polymerase chain reaction (qRT-PCR). The results showed that the coding region of TPM3 spans 855 bp, with the 161st base being the T base, encoding a protein with 284 amino acids and 19 phosphorylation sites. This protein demonstrated high conservation across species while displaying a predominant α-helix secondary structure despite being an unstable acidic protein. Notably, a noticeable increase in TPM3 expression was observed in the longissimus dorsi muscle and myocardium of calves and adult cattle. Expression patterns varied during different stages of myoblast differentiation. Functional studies that involved interference with TPM3 in Qinchuan cattle myoblasts revealed a very significantly decrease in S-phase cell numbers and EdU-positive staining (P < 0.01), and disrupted myotube morphology. Moreover, interference with TPM3 resulted in significantly (P < 0.05) or highly significantly (P < 0.01) decreased mRNA and protein levels of key proliferation and differentiation markers, indicating its role in the modulation of myoblast behavior. These findings suggest that TPM3 plays an essential role in bovine skeletal muscle growth by influencing myoblast proliferation and differentiation. This study provides a foundation for further exploration into the mechanisms underlying TPM3-mediated regulation of bovine muscle development and provides valuable insights that could guide future research directions as well as potential applications for livestock breeding and addressing muscle-related disorders.

Development of a Predictive Model for Iron Levels in Bovine Muscle Tissue Using Hair as a Predictor.

The assessment of iron levels in cattle muscle tissue is crucial for livestock management because it influences both animal health and meat quality, key factors in sustainable development. This study aimed to develop an optimal model for noninvasively predicting the iron content in Hereford cattle muscle tissue, contributing to a comprehensive understanding of the animals' elemental status. The research involved the atomic absorption analysis of muscle tissue and hair samples from cattle. A regression model was constructed using the least squares method to identify the most effective approach. These findings have ecological applications, aiding in evaluating environmental health and establishing acceptable iron thresholds for animals. The proposed mathematical model utilizing biomarkers (levels of Mg, K, Fe, Al, Cr in hair) will allow for the assessment of iron levels in cattle muscle tissue throughout the period of productive use, with the possibility of adjustment and tracking the changes in elemental status over time. The utilization of the developed method will enable the diagnosis of animal elementosis and assessment of the iron level burden. Subsequently, this will allow for the improvement of the qualitative characteristics of the final product. Thus, the obtained data contribute to fundamental knowledge regarding the content and variability of iron levels in the muscle tissue of cattle.

Unlocking the Transcriptional Control of NCAPG in Bovine Myoblasts: CREB1 and MYOD1 as Key Players.

Muscle formation directly determines meat production and quality. The non-SMC condensin I complex subunit G (NCAPG) is strongly linked to the growth features of domestic animals because it is essential in controlling muscle growth and development. This study aims to elucidate the tissue expression level of the bovine NCAPG gene, and determine the key transcription factors for regulating the bovine NCAPG gene. In this study, we observed that the bovine NCAPG gene exhibited high expression levels in longissimus dorsi and spleen tissues. Subsequently, we cloned and characterized the promoter region of the bovine NCAPG gene, consisting of a 2039 bp sequence, through constructing the deletion fragment double-luciferase reporter vector and site-directed mutation-identifying core promoter region with its key transcription factor binding site. In addition, the key transcription factors of the core promoter sequence of the bovine NCAPG gene were analyzed and predicted using online software. Furthermore, by integrating overexpression experiments and the electrophoretic mobility shift assay (EMSA), we have shown that cAMP response element binding protein 1 (CREB1) and myogenic differentiation 1 (MYOD1) bind to the core promoter region (-598/+87), activating transcription activity in the bovine NCAPG gene. In conclusion, these findings shed important light on the regulatory network mechanism that underlies the expression of the NCAPG gene throughout the development of the muscles in beef cattle.