Search Results (333)

The development of a fibrous-structured meat alternative that can perfectly mimic the tribology of the meat is considered to be extremely challenging. In this study, a bottom-up technique, wet spinning, was used to produce a fiber-like structure similar to muscle fiber. Different protein concentrations (0% to 16%) of wheat protein, pea protein isolates, and sodium alginate (2%) were used as an emulsifier and compared with the conventional meat (longissimus dorsi muscle) from a barrow in terms of physicochemical (pH, color, moisture content, cooking loss), textural (Texture profile and Warner–Bratzler Shear Force), and sensory parameters. The results from the study showed that the ratio of protein concentration significantly affected the solution behavior, leading to change in the spinnability of solution. The combined protein formulations displayed by a greater range of physicochemical and textural properties, especially hardness and WBSF, ranged from 22 N to 32.20 N and 4.26 to 4.71 kg/cm² in comparison to each other (p < 0.05). However, principal component analysis has shown that the overall profiling was significantly different than that of conventional meat (p < 0.05). The overall results suggested that the blend of wheat protein and pea protein isolate shows great potential for preparing a variety of structured meat alternatives by optimizing the concentration based on the desired product profiling. Full article

To clarify the relationship between muscle development and meat quality in Ziwuling black goats, this study used the longissimus dorsi muscle of 6-month-old and 12-month-old goats as samples. With HE staining, fast–slow myofiber immunofluorescence double staining, and transcriptome sequencing, this study analyzed muscle structure, myofiber type transformation, and molecular regulation. Results showed that 6-month-olds had higher myofiber density and smaller diameter; 12-month-olds showed myofiber hypertrophy (larger diameter); immunofluorescence revealed more fast-twitch myofibers (Type II) at 6 months and increased slow-twitch ones (Type I) at 12 months. Transcriptome sequencing identified 387 differentially expressed genes (DEGs: 156 upregulated, 231 downregulated). GO analysis indicated that DEGs are involved in skeletal muscle growth, cAMP biosynthesis, etc.; KEGG analysis showed enrichment in arginine–proline metabolism and AMPK/MAPK signaling pathways (AMPK regulates fatty acid metabolism genes like ACACB/CPT1A; arginine–proline metabolism relates to muscle maturation). WGCNA clustered genes into nine modules (MEblue correlated with myofiber density/MAPK; MEgreen correlated negatively with diameter but positively with density, involving PPARGC1A/AMPK). In conclusion, protein nutrition at 6 months (promote myofiber proliferation) and regulating energy intake at 12 months (improve meat quality) are recommended, and 12 months is the optimal slaughter age. Full article

Pig growth is an economically important trait regulated by multiple genes and signaling pathways. To explore the molecular mechanisms underlying muscle growth, RNA sequencing was conducted to compare the transcriptomic profiles of the longissimus dorsi muscle between indigenous Liaoning Black pigs (CH) and commercial Duroc pigs (HD). Muscle samples from six CH (three males and three females) and six HD (three males and three females) pigs were analyzed. Functional annotation, Gene Ontology (GO) and KEGG enrichment, and protein–protein interaction (PPI) analyses were performed. Sequencing yielded 12 high-quality datasets (Q20 > 97%, Q30 > 93%). Comparative analysis identified 5051 DEGs in females (CHF vs. HDF; 2310 upregulated and 2681 downregulated) and 9972 DEGs in males (CHM vs. HDM; 4984 upregulated and 4988 downregulated). GO terms were mainly enriched in organonitrogen compound and protein metabolic processes, while KEGG pathways were enriched in focal adhesion and insulin signaling. PPI analysis highlighted hub genes ITGB1, SRC, MYL2, PRKACA, and MAPK3. qPCR validation showed strong agreement with RNA-seq data. These findings provide valuable insights into the molecular basis of divergent muscle growth between pig breeds. Full article

Despite growing evidence on the adaptive movement patterns that horses adopt during water treadmill (WT) exercise, underlying adaptations in muscle activity remain uninvestigated. This feasibility study aimed to develop a method for the synchronous measurement of muscle activity and movement of horses during WT exercise. Combined surface electromyography (sEMG) (2000 Hz) from selected hindlimb (biceps femoris, gluteus medius, tensor fasciae latae) and epaxial (longissimus dorsi) muscles, and three-dimensional kinematic (200 Hz) data from the back and pelvis of one (n = 1) horse were collected during overground (OG), dry treadmill (TM), and WT walking conditions. Statistical parametric mapping evaluated differences in time- and amplitude-normalised sEMG and thoracolumbar and pelvis kinematic waveforms between conditions. Distinct, significant (p < 0.05) adaptations in hindlimb and epaxial muscle activation patterns and axial and pelvic kinematics, were observed in this horse across exercise conditions. Adaptive muscle activity was most pronounced in this horse during WT, compared to OG walking. These findings demonstrate the feasibility of this method, which combines sEMG and motion capture technologies to synchronously quantify equine movement and muscle activation patterns during WT exercise. This justifies the replication of this work in a larger sample of horses to inform evidence-based training and rehabilitation programmes. Full article

Lycium ruthenicum leaves (LRL), as an agricultural by-product rich in bioactive compounds, can be used as an unconventional feedstuff in animal diets and have the potential to improve animal health. This study investigates the effects of dietary supplementation with graded levels of LRL on rumen fermentation, meat amino acid and fatty acid profiles, and rumen bacterial diversity in sheep. Forty three-month-old male Dorper × Hu crossbred F1 lambs with an initial body weight of 29.58 ± 2.06 kg were randomly assigned to four groups (n = 10). Over a continuous 63-day trial period, the lambs were fed diets containing 0%, 5%, 10%, and 15% LRL, respectively. At the end of the trial, rumen fluid and longissimus dorsi muscle samples were collected to assess rumen fermentation characteristics, bacterial community structure, and meat quality. The results showed that: (1) The concentrations of acetate, butyrate, and total volatile fatty acids (TVFA) in the rumen were increased in the LRL5% group (p < 0.05 or p < 0.01). (2) The relative abundance of the phylum Firmicutes and the genus Ruminococcus increased (p < 0.05), while the relative abundance of the genus Prevotella decreased (p < 0.05) in the LRL5% group. (3) Meat L* increased (p < 0.05), and a* decreased (p < 0.05) in the LRL-supplemented groups. (4) The content of sweet amino acids in meat increased in LRL groups (p < 0.05). Moreover, the contents of non-essential amino acids, sweet amino acids, and total amino acids in meat increased linearly with increasing dietary LRL levels (p < 0.05). (5) Compared with the CON group, the content of C18:0 in meat decreased in the LRL5% group (p < 0.05), while the content of C20:1 increased in the LRL10% group (p < 0.05). In conclusion, dietary supplementation with LRL can improve meat quality, rumen fermentation, and rumen bacterial community structure in sheep. The recommended dietary inclusion level of LRL ranges from 5% to 15%. Full article

The mechanistic underlying the favorable meat quality of Tibetan pigs has not been fully elucidated. This study integrated flavor chemistry, histomorphology, and proteomics to explore the structural and molecular features of their meat. Longissimus dorsi samples from Tibetan and Duroc pigs (n = 6 each biological replicates) were quantitatively analyzed for amino acid profiling, histological assessment, and proteomic characteristic. Statistical approaches included weighted correlation network analysis, t-tests, and functional enrichment. Tibetan pork contained 34 mg/100g more total free amino acids, notably sweet-tasting Ala (+49.2%) and Thr (+32.2%). Muscle fiber density was >250% higher and diameter > 30% smaller, indicating finer texture. Proteomics revealed 149 upregulated proteins, including 57 mitochondrial differentially expressed proteins (DEPs)—11 of which belonged to electron transport chain complexes (e.g., NDUFAB1, COX2). The significant enrichment of oxidative phosphorylation pathways may be associated with mitochondrial efficient energy metabolism under hypoxic in Tibetan pigs, potentially linking to the breed’s unique meat characteristics. Ala levels showed strong correlations with metabolic and structural protein modules. The finer fibers and mitochondrial protein profile of Tibetan pigs contribute to higher amino acid content and meat quality. This structural–metabolic–flavor axis supports both hypoxia adaptation and high meat quality. Given the central role of mitochondrial electron transport chain (ETC) proteins in energy metabolism and Ala in flavor presentation, their synergistic action provides a molecular bridge between hypoxia adaptation and meat quality. Therefore, this study suggests that ETC and Ala may serve as key biomarkers for meat quality differences, offering new perspectives for meat quality research. Full article

To investigate the gene regulatory mechanisms underlying muscle development in Oula sheep at different growth stages, under supplementary feeding, particularly the shift in core regulatory mechanisms governing muscle development from the fetal stage to the postnatal period, we conducted transcriptomic sequencing and comparative analysis of the longissimus dorsi muscle collected during the embryonic, lamb, and adult stages. Differentially expressed genes (DEGs) potentially associated with muscle growth and development were identified across various age phases. Furthermore, Short Time-series Expression Miner (STEM) analysis was employed to decipher the temporal expression patterns of these DEGs. The results indicated that metabolic processes related to carbohydrates, energy, and amino acids were enhanced with increasing age in Oula sheep muscle. Comparative analysis between different growth stages revealed that the functional enrichment of DEGs was directly associated with changes in skeletal muscle development, with significant enrichment in biological pathways such as ECM–receptor interaction, PI3K-AKT signaling pathway, and protein digestion and absorption. Additionally, we observed that PTPRC, IL10, NDUFAB1, BUB1, BUB1B, CDK1, ITGB3, and ITGB2 may play pivotal roles in the regulation of muscle growth and development across different stages in Oula sheep. These findings provide theoretical support for the understanding of the genetic regulatory mechanisms underlying muscle development in Oula sheep. Full article

To investigate the molecular mechanisms underlying muscle fiber development in different pig breeds and their impact on meat quality, this study collected the longissimus dorsi muscle of the indigenous Huainan pig and the commercial Large White pig at four developmental stages (0, 7, 14, and 21 days postnatal). Muscle fiber types were identified using myosin ATPase staining, while transcriptomics and non-targeted metabolomics were employed to analyze differences in gene expression and metabolite composition. The results showed that the Huainan pig had a higher proportion of oxidative muscle fibers, indicating superior aerobic metabolic capacity and meat quality. Transcriptome data identified 18 differentially expressed genes common to both pig breeds, including KLF4, NOS1, SH3KBP1, and TRARG1, which were upregulated in Huainan pigs to regulate muscle fiber type composition and meat quality by influencing mitochondrial function, nitric oxide synthesis, and glucose/lipid metabolism. Metabolomics analysis revealed significantly elevated levels of carnosine, citrulline, serine, and glycerol-3-phosphate in Huainan pigs, which are associated with metabolic pathways promoting muscle fiber transformation via enhancing energy supply, antioxidant capacity, and fatty acid oxidation. Notably, integrated transcriptome–metabolome analysis showed that oxidative metabolism genes (e.g., KLF4) and metabolites (e.g., citrulline) formed an AMPK-mediated ‘gene–metabolite’ loop in Huainan pigs, which synergistically promotes mitochondrial function and fiber differentiation. In summary, this study provides new insights into the molecular mechanisms underlying meat quality differences between pig breeds and offers a theoretical basis for the breeding and development of high-quality pork. Full article

The Aubrac cattle breed, native to France and increasingly adopted in Eastern Europe, is known for producing tender, flavorful, and well-marbled beef. Despite its growing popularity, limited data exist on its nutritional profile and implications for human health. This study evaluates carcass traits and protein quality in the Longissimus dorsi muscle of male and female Aubrac cattle raised under semi-intensive systems. Special attention was given to essential and semi-essential amino acids, which exceeded FAO/WHO reference requirements by 60.25%, 97.43%, and 221.49% for children, youth individuals, and adults, respectively, confirming superior protein quality. The high amino acid concentration (up to 30.59 g/100 g protein) and biological value confirm superior protein quality. Furthermore, the fatty acid profile reveals a favorable balance between saturated and unsaturated fats, with oleic acid predominance and a moderate atherogenic index, suggesting cardiovascular benefits. These findings support classifying Aubrac beef as a functional protein source with potential health advantages, reinforcing its role in sustainable cattle production, dietary planning, and consumer education. This study provides insights into factors influencing beef quality, connecting cattle breed and production system with nutritional value and health benefits. Full article

Despite its increasing use in veterinary rehabilitation, practical constraints—such as skin preparation and single-use electrodes—limit the wider adoption of surface electromyography (sEMG). Having conventional pre-gelled Ag/AgCl electrodes as reference, we made a pioneering comparison of the performance of reusable soft polymeric dry electrodes for recording paraspinal muscle activity in dogs during treadmill walking. Twelve clinically healthy Dachshunds from both genders were evaluated under two conditions, namely: (i) dry electrodes on untrimmed hair; and (ii) pre-gelled electrodes after trichotomy. Signals were acquired from the longissimus dorsi muscle at 1 kHz, processed with standardized filtering and rectification, and analyzed in both time and frequency domains. Dry electrodes yielded higher amplitude and Root Mean Square (RMS) values, but slightly lower power spectral density metrics when compared to pre-gelled electrodes. Nevertheless, frequency-domain results were broadly comparable between configurations. Dry electrodes reduce the preparation time, avoid hair clipping, and allow reusability without major signal degradation. While pre-gelled electrodes may still offer marginally superior stability during movement, our results suggest that soft polymeric dry electrodes present a feasible, less invasive, and more sustainable alternative for canine sEMG. These findings support further validation of dry electrodes in clinical populations, particularly for neuromuscular assessment in intervertebral disk disease. Full article

Background/Objectives: This study systematically investigated the expression characteristics of the ALDOA gene in skeletal muscle cells and its effects on cell proliferation, apoptosis, and differentiation. Methods: We constructed an ALDOA overexpression vector and transfected it into C2C12 cells and porcine skeletal muscle satellite cells. Results: We found that ALDOA exhibited the highest expression in the longissimus dorsi muscle and was primarily localized in the cell nucleus. Overexpression of ALDOA significantly inhibited cell proliferation, induced G0/G1 phase arrest, and downregulated the expression of proliferation-related genes such as CDK2 and Cyclin D1. Concurrently, ALDOA overexpression markedly promoted apoptosis. Regarding differentiation, although ALDOA expression was upregulated during differentiation, its overexpression significantly suppressed the expression of myogenic differentiation-related genes (such as MYOD, MYOG, MEF2C), suggesting a negative regulatory role in differentiation control. Conclusions: This study reveals the multifaceted regulatory functions of ALDOA in skeletal muscle cells, providing experimental evidence for deepening the understanding of its mechanisms in muscle development and regeneration. This study provides the first functional evidence that ALDOA acts as a multifunctional regulator in skeletal muscle cells, negatively governing cell growth and fate decisions by inhibiting proliferation, promoting apoptosis, and impeding myogenic differentiation, thereby extending its role beyond glycolysis to direct governance of cellular processes. This study reveals for the first time that ALDOA possesses dual functions in muscle cells, regulating both metabolism and transcription. Full article

This study investigated the effects of different crude protein (CP) levels on growth performance, carcass traits, meat quality, and fatty acid composition in Ningxiang finishing pigs. A total of 200 pigs (52.52 ± 0.41 kg) were assigned to five dietary treatments: high-protein (HP, 15.56%), moderate-high-protein (MHP, 13.99%), moderate-protein (MP, 12.94%), moderate-low-protein (MLP, 11.90%), and low-protein (LP, 10.31%). Feeding the MLP diet significantly improved average daily gain (ADG) compared to HP and LP diets (p < 0.05). Pigs fed the MP diet had higher lean meat percentage than those on the LP diet (p < 0.05), while both HP and MP diets reduced carcass fat percentage (p < 0.05). The LP diet significantly increased a*, pH_45min, intramuscular fat (IMF), and C18:1n9c, while decreasing C23:0 and C20:3n6 in the longissimus dorsi muscle (p < 0.05). Liver metabolomics revealed that the LP diet inhibited nicotinate and nicotinamide metabolism (p < 0.05), accompanied by downregulation of genes related to the tryptophan–niacin metabolism and upregulation of genes involved with hepatic lipogenesis (p < 0.05). In muscle, the LP diet inhibited AMPK signaling via decreased p-AMPK expression, leading to increased IMF content (p < 0.05). In summary, the optimal growth performance of Ningxiang finishing pigs was achieved with a CP level of 11.90%. Additionally, the LP diet enhanced meat quality by modulating hepatic niacin metabolism and AMPK signaling. Full article

The Krüppel-like factor (KLF) family of transcription regulators plays pivotal roles in adipogenesis, myogenesis, and metabolism. While comprehensively studied in humans and mice, its characterization in cattle remains limited, especially within the skeletal muscle niche. This study aimed to systematically characterize the KLF family in Bos taurus and elucidate its role in breed-specific muscular development. We employed an integrated approach of comparative genomics and single-nucleus RNA sequencing (snRNA-seq) on longissimus dorsi muscle from Angus (ANG, beef breed) and Holstein (HST, dairy breed) cattle. Phylogenomic analysis identified 14 KLF genes, revealing evolutionary conservation and potential functional divergence. snRNA-seq delineated 11 distinct cell populations and uncovered cell-type-specific expression patterns of KLFs. Further machine learning based analysis pinpointed KLF6, KLF9, KLF10, and KLF12 as key global drivers of transcriptional differences between breeds, while KLF6 was identified as a major cell-type-specific contributor in lymphatic endothelial cells. Our work provides a foundational resource for understanding the KLF family in cattle and identifies promising candidate genes for improving meat production traits through molecular breeding. Full article

Background/Objectives: Chronic ankle instability is a common issue after lateral ankle sprain. The DMA Clinical Pilates method hypothesizes impairments in tibialis anterior and fibularis longus muscles. Methods: A total of 14 adults with chronic ankle instability, and 15 recovered and 16 healthy individuals were prospectively recruited and assessed for lower back, hip, knee, and ankle muscle activities during dominant and non-dominant sides single-leg stand on stable and unstable surfaces using wireless surface electromyography. Results: The study found consistent dysfunction in tibialis anterior muscle activity in adults with chronic ankle instability when compared with healthy adults during single-leg stand on stable and unstable surfaces, and against recovered individuals on unstable surface. As compared to healthy controls, chronic ankle instability group showed higher vastus lateralis activation during dominant side single-leg stand across surface conditions and during dominant side single-leg stand, while the higher dominant side longissimus dorsi activity on stable surface changed to higher dominant side medial gastrocnemius activity on unstable surface. As compared to recovered controls, chronic ankle instability group also showed higher gluteus medius and fibularis longus muscle activities on unstable surface. Conclusions: Tibialis anterior muscle is the main dysfunction among individuals with chronic ankle instability side. Full article

Kazakh horses are renowned for their endurance and adaptability, with distinct muscle groups such as the longissimus dorsi (LD) and biceps femoris (BF) muscles serving specialized functions. However, the molecular mechanisms underlying the functional specialization of these muscles in Kazakh horses remain poorly understood. This study aims to address this gap by utilizing single-cell RNA sequencing (scRNA-seq) to investigate the transcriptomic differences between these muscle groups, with a focus on understanding their molecular adaptations. Our analysis revealed that the BF muscle, specialized for explosive movements, exhibited upregulation of genes associated with anaerobic metabolism, muscle contraction, and oxidative stress response, reflecting its reliance on glycolysis for sustained energy production. In contrast, the LD muscle, primarily responsible for postural support and endurance, showed a metabolic shift toward lipid utilization and energy production. Differential gene expression analysis also revealed distinct enrichment in biological pathways, with LD cells being enriched in pathways related to muscle contraction and calcium signaling, while BF cells were enriched in energy metabolism pathways. These findings provide valuable insights into the molecular adaptations of Kazakh horses’ muscle tissues, highlighting the functional specialization of LD and BF muscles and offering a foundation for future research on improving muscle performance and breeding programs in equines. Full article