Search Results (45)

In recent years, with changes in dietary structure, beef has become the third most consumed meat in China after pork and chicken, with its consumption increasing by approximately 50%. The quality and commercial value of beef vary considerably across different muscles. However, due to the high similarity in the appearance of beef cuts and strong background interference, traditional image features are often insufficient for accurate classification. In this study, an improved convolutional neural network based on YOLOv11 was proposed. Four beef muscles were categorized: sirloin (longissimus dorsi), fillet/tenderloin (psoas major), oyster blade (infraspinatus), and ribeye (longissimus thoracis). A dataset comprising 3598 images was established to support model training and validation. We divided the dataset into training, testing, and validation sets in a 6:2:2 ratio. To enhance model performance, wavelet convolution (WTConv) was employed to effectively expand the receptive field and improve image understanding, while a large separable kernel attention (LSKA) module was introduced to strengthen local feature representation and reduce background interference. Comparative experiments were conducted with other deep learning models as well as ablation tests to validate the proposed model’s effectiveness. Experimental results demonstrated that the proposed model achieved a classification accuracy of 98.50%, with Macro-Precision and Macro-Recall reaching 97.38% and 97.38%, respectively, and a detection speed of 147.66 FPS. These findings confirm the potential of the YOLOv11n-cls model for accurate beef classification and its practical application in intelligent meat recognition and processing within the Chinese beef industry. Full article

This study aimed to provide the first characterization of the traditional farming systems and meat quality traits of the Black Alpine pig (BAP), an ecotype under recovery originating in the Italian Central Alps, reared under real, actual conditions. Productive and reproductive data were collected through on-farm visits from six BAP farms located in Northern Italy. Longissimus dorsi (LD) muscle and backfat samples from BAPs were collected in the same farms and analyzed for color, tenderness, proximate composition, and fatty acid profile. For exploratory purposes and to provide a descriptive benchmark of commercial pork (CP) quality, loin samples were purchased from the retail market. PLS-DA served as a discriminant model between BAP and CP meat samples on a multivariate data matrix. BAP farming was characterized as an en plein air system with high outdoor access and reliance on natural vegetation. BAPs showed high rusticity and slow growth. The LD muscle was characterized by a firm texture, an intense dark-red color, and a high proportion of polyunsaturated fatty acids, reflecting traditional rustic meat features associated with the interaction between dietary, environmental, and genetic factors. Our preliminary results provided novel insights into BAP farming practices and meat quality, supporting the maintenance of this genetic resource through traditional farming and the preservation of biodiversity in alpine livestock, offering exploratory evidence of the current BAP farming system. Full article

Pork is one of the most widely consumed meats worldwide, with tenderness and intramuscular fat (IMF) content serving as key determinants of consumer acceptance. The rising demand for high-quality pork underscores the need to better understand the molecular mechanisms regulating IMF deposition and meat tenderness. In this study, we systematically examined the tenderness and IMF in the Longissimus dorsi (LD) muscle of 104 eight-month-old Songliao black pigs and Leixiang pigs raised under identical conditions. In addition, three pigs from each breed were randomly selected for multi-omics analyses, including Assay for Transposase-Accessible Chromatin sequencing (ATAC-seq), transcriptomics, and proteomics to elucidate the molecular networks underlying IMF deposition and tenderness. We identified a total of 2635 differentially accessible chromatin (DARs) regions associated with 2006 functional genes and 351 regulatory transcription factors, predominantly enriched in adipocyte differentiation and muscle metabolism pathways. Transcriptome analysis revealed 624 differentially expressed genes (DEGs) involved in lipid metabolism and tissue structure maintenance. While proteomic profiling detected 153 differentially expressed proteins (DEPs) enriched in fatty acid degradation/metabolism, PPAR signaling, energy metabolism, and thermogenesis pathways. Further, combined integrated multi-omics analysis identified nine candidate genes (MBP, DCLK1, COL3A1, ART3, COL14A1, PDK4, VCAN, LIPE, and GPX1) and transcription factor–target interaction networks predicted key regulatory factors including MEF2A/C/D, PR, GR, AR-HALLSITE, NF1-HALLSITE, AP4, TCF21, MYOG, ATOH1, TCF12, BHLHA15, MYF5, ASCL1, and SIX2, which were potentially involved in the regulation of meat tenderness and IMF deposition. These findings provide novel insights into the molecular determinants of IMF and tenderness, offering valuable targets for improving meat quality through genetic breeding strategies. 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 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

This research examined the phenotypic and genotypic variability of traits assessed in the gilt performance test and their subsequent impact on gilt selection. The traits evaluated in the gilt performance test were analyzed on two pig farms over a period of 3 consecutive years. A total of 3664 gilts were included in the research. At the end of the test, body weight, backfat thickness (BF1 and BF2), and longissimus dorsi muscle depth (MLD) were measured using an ultrasound device. The following breeds were evaluated on the farms: Landrace (L)–1981 gilts, Large White (LW)–1344 gilts, and Duroc (D)–339 gilts. In the analyzed population, direct genetic effects accounted for 0.2647 of the total variation in age at the end of the test (AET). Heritability coefficients of 0.37 for BF1 and 0.35 for BF2 indicate that these traits are highly heritable in the studied population. On the other hand, the heritability coefficient for the depth of MLD, which is 0.23, places this trait in the group of medium heritable traits. High heritability coefficients of these traits indicate great potential for genetic improvement through selection. The use of well-designed selection programs aimed at these traits can significantly accelerate the genetic improvement of the population and have an impact on the economic profit of pork production. Full article

Background: Crossbreeding strategies that combine the growth performance of Western pig breeds with the meat quality traits of Chinese indigenous breeds have garnered considerable interest. Duroc pigs are known for their high growth efficiency but have relatively low intramuscular fat (IMF) content. In contrast, native breeds like the Diannan Small-Eared pig exhibit superior pork quality with higher IMF levels. This study aimed to compare the muscle growth characteristics and molecular mechanisms between Duroc × Landrace × Yorkshire (DLY) and Duroc × Berkshire × Diannan Small-Eared (DBD) pigs. Methods: The longissimus dorsi tissue of 210-day-old DLY and DBD pigs was collected for analysis. HE staining assessed muscle fiber characteristics, IMF content was measured, and ELISA quantified muscle-derived growth and development-related factors. Transcriptome sequencing was conducted, followed by differential gene expression analysis, Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG), and protein–protein interaction (PPI) analyses. Functional validation of key genes was performed in C2C12 cells. Results: DBD pigs exhibited significantly larger muscle fiber diameter and higher IMF content compared to DLY pigs. IGF1 and GH levels were elevated in DBD pigs. Transcriptome analysis identified 185 upregulated and 102 downregulated genes, with enrichment in pathways including PI3K-Akt, MAPK, FoxO, and cGMP-PKG signaling. ACSL1 and FABP3 were functionally validated, showing promotion of differentiation and inhibition of proliferation in C2C12 cells. Conclusions: DBD pigs exhibit superior muscle growth traits and higher IMF content compared to DLY pigs. ACSL1 and FABP3 may serve as key regulators of muscle development in pigs. Full article

In the efforts towards germplasm innovation of livestock and poultry, strategies to improve meat quality have faced some increasingly challenging and dynamic concerns. Intramuscular fat (IMF) content and backfat thickness are two important traits contributing to meat quality. MicroRNAs (miRNAs)—a class of endogenous noncoding RNAs maintaining cell homeostasis by inhibiting target gene expression—have been proven as critical regulators of body fat deposition, thus affecting farm animal production. Our previous in vitro and in vivo models of pigs have clarified that miR-130b overexpression can obviously suppress adipogenesis of subcutaneous preadipocytes and lower backfat thickness. However, the way miR-130b regulates proliferation and adipogenesis of primary cultured porcine intramuscular preadipocytes (PIMPA) and the underlying mechanism are still unknown. PIMPA derived from longissimus dorsi muscle were employed to examine the role of miR-130b in proliferation and adipogenesis and to further elucidate its underlying mechanism. Lipid deposition in cytoplasm was evaluated by TG quantification and ORO-staining, and EDU-staining was employed to measure cell proliferation. Adipogenic and proliferation-related gene expression were conducted by qPCR and Western blot. MiR-130b overexpression markedly stimulated proliferation of PIMPA by increasing cell cycle-related gene expression. Furthermore, overexpression of miR-130b significantly inhibited adipogenic differentiation of PIMPA, mainly by inhibiting expression of adipogenic differentiation marker genes PPAR-γ and SREBP1. In addition, we proved that miR-130b significantly inhibited expression of PPAR-γ downstream target genes and ultimately repressed adipogenesis. Ssc-miR-130b accelerated proliferation but inhibited adipogenic differentiation of PIMPA, contributing to an enhanced knowledge of the function of ssc-miR-130b in lipid deposition, and providing potential implications for enhancing pork quality. Full article

Background/Objectives: Early postmortem mitochondrial function and apoptotic activation affect meat quality development. Nicotinamide riboside (NR) supplementation to pigs prior to harvest can improve pork color stability, but its mechanism remains unclear. This study aimed to evaluate the impact of NR supplementation on early postmortem mitochondrial functionality and apoptosis. Methods: Sixteen pigs (N = 16) were individually fed a control or NR-supplemented diet (30 mg·kg body weight⁻¹·d⁻¹) for 10 days prior to harvest. Longissimus dorsi muscle samples were collected at 45 min and 24 h postmortem and analyzed for mitochondrial functionality using high-resolution respirometry and apoptotic protein abundance (apoptosis regulator Bcl-2-associated X (BAX), apoptotic inducing factor (AIF), and caspase 3 (CASP3)) via immunoblotting. Results: NR-supplemented muscle exhibited lower proton leak-associated respiration at 45 min postmortem (p < 0.05), followed by a slower accumulation of mitochondrial outer membrane permeabilization (MOMP; p < 0.05) and a slower loss of mitochondrial integral function (p < 0.05) from 45 min to 24 h postmortem. NR supplementation decreased BAX abundance at 45 min postmortem but increased mature AIF abundance (62 kDa) at 24 h postmortem (p < 0.05). The abundance of CASP3 fragments (~29 kDa) decreased from 45 min to 24 h postmortem, independent of treatment (p < 0.05). Conclusions: NR supplementation demonstrated the potential to protect mitochondrial integral function and alleviate apoptotic activation in early postmortem porcine skeletal muscle, which might contribute to a higher meat color stability in NR-supplemented pork during retail display. Full article

Meat quality is a complex trait that exhibits significant variation across pig breeds, and the regulatory mechanisms governing pork meat quality are not fully elucidated. We compared the transcriptomics and metabolomics of the longissimus dorsi (LD) muscle between the Songliao Black Pig (SBP) and Large White × Landrace Pig (LWLDP) to investigate breed-specific differences in meat quality and underlying regulatory pathways. The results showed that SBP meat had a higher marbling score and backfat thickness, a richer color, a lower shear force, and reduced drip loss. Fatty acid (FA) analysis identified 15 significant FAs in the LWLDP, with docosahexaenoic acid (DHA) in the SBP, while amino acid (AA) analysis revealed no breed-based differences. Transcriptome analysis identified 134 upregulated and 362 downregulated genes in the SBP. Protein–protein interaction (PPI) network analysis found 25 key genes, which are associated with muscle development, fat deposition, and overall meat quality, while genes in the insulin signaling pathway, such as PPP1R3B, PPARGC1A, SOCS1, EIF4E, PRKAR2A, PRKAG2, and FASN, play a crucial role in balancing fat metabolism and catabolism. Metabolomic analysis identified 89 upregulated and 10 downregulated metabolites in the SBP, primarily involved in fructose and mannose metabolism, amino acid biosynthesis, nucleotide sugar metabolism, and glucagon signaling pathways. Gene–metabolite association analysis found that the PPP1R3B gene had a strong association with Thr-Leu, Maltol, D-myo-Inositol-4-phosphate, and Fructose-6-phosphate, while MYOG correlated with Mannose-6-phosphate, Fructose-1-phosphate, Mannose-1-phosphate, and Glucose-6-phosphate. In contrast, NR4A3 and PPARGC1A showed a strong negative correlation with most upregulated metabolites. In conclusion, this study identified functional genes, elucidated the mechanisms associated with meat quality traits, and identified gene–metabolite associations involved in energy metabolism, muscle development, and fat deposition, providing valuable insights into the molecular mechanisms that regulate meat quality between pig breeds. Full article

This experiment aimed to explore the effects of flavonoids in Fructus Aurantii Immaturus (FFAI) on carcass traits, meat quality, and the antioxidant capacity of finishing pigs. The results indicated that the addition of an appropriate amount of FFAI into their diet could significantly reduce the backfat thickness and perirenal fat percentage of finishing pigs, as well as the drip loss, water-holding capacity, shear force, and the levels of lactate, glucose-6-phosphate, glucose, ATP, phosphofructokinase, and pyruvate in the longissimus dorsi (LD) muscle. It also elevated the levels of flavor amino acids such as glutamate, serine, and threonine, and enriched the composition of flavor substances, including benzene and octanal, which significantly contributed to the enhancement of pork flavor. Furthermore, it enhanced the expression levels of MyHC I and MyHC IIa. In summary, the appropriate addition of FFAI to the diet could improve the carcass traits, meat quality, and antioxidant capacity of finishing pigs. The optimal level of FFAI supplementation is 0.12%. Full article

Intramuscular fat (IMF) content significantly influences pork tenderness, flavor, and juiciness. Maintaining an optimal IMF range not only enhances nutritional value but also improves the taste of pork products. However, traditional IMF measurement methods are often invasive and time-consuming. Ultrasound imaging technology offers a non-destructive solution capable of predicting IMF content and assessing backfat thickness as well as longissimus dorsi muscle area size. A two-stage multimodal network model was developed in this study. First, using B-mode ultrasound images, we employed the UNetPlus segmentation network to accurately delineate the longissimus dorsi muscle area. Subsequently, we integrated data on backfat thickness and longissimus dorsi muscle area to create a multimodal input for IMF content prediction using our model. The results indicate that UNetPlus achieves a 94.17% mean Intersection over Union (mIoU) for precise longissimus dorsi muscle area segmentation. The multimodal network achieves an R² of 0.9503 for IMF content prediction, with Spearman and Pearson correlation coefficients of 0.9683 and 0.9756, respectively, all within a compact model size of 4.96 MB. This study underscores the efficacy of combining segmented longissimus dorsi muscle images with data on backfat thickness and muscle area in a two-stage multimodal approach for predicting IMF content. Full article

The quality of frozen pork is adversely affected upon thawing. In this study, the influence of various thawing methods for frozen pork, including cold water (18 °C), room temperature (18 °C), and refrigeration (4 °C) thawing, on physicochemical and nutrient substances were examined. The pork samples (a Chinese local breed: Anqing six-end-white pigs), which were thawed through the above conditions, were compared with controls (fresh porcine longissimus dorsi). Analyses were carried out to determine porcine longissimus dorsi shear force, pH value, crude protein content, antioxidant capacity, amino acid content, and fatty acid content. The results indicated that the shear force, pH value, crude protein content, total antioxidant capacity (T-AOC), and total superoxide dismutase (T-SOD) content of the porcine longissimus dorsi muscle significantly decreased via the three thawing methods compared with the control group (p < 0.05). However, malondialdehyde (MDA) content, intramuscular fat content, inosinate and cholesterol content, essential amino acid content, and umami amino acid proportion in the cold thawing group were not significantly different from the control group (p > 0.05), but there were significant differences between the other two groups. The MDA content of the air thawing and hydrostatic thawing groups significantly increased compared with the control group (p < 0.05), with it being 42.6% and 50.8% higher than the control group, respectively. In addition, the monounsaturated fatty acid content in the pork subjected to the three thawing methods significantly increased compared with the control group (p < 0.05), and the monounsaturated fatty acid content after cold thawing and hydrostatic thawing increased by 18.2% and 21.6%, respectively. In conclusion, refrigeration had less influence on the quality of the Anqing six-end-white pork and was the most suitable thawing method. This study provides a theoretical reference for frozen pork preservation for improving food quality and availing its economic benefits. Full article

Heat stress is a significant environmental problem that has a detrimental impact on animal welfare and production efficiency in swine farms. The current study was conducted to assess the effect of low-intensity showers, provided during critical high-temperature hours daily, on body external temperature, feeding pattern, and carcass and meat quality characteristics in fattening pigs. A total of 400 animals (200 barrows and 200 gilts) were randomly allotted in 40 pens. A shower nozzle was installed over 20 pens (half barrows and half gilts) where pigs received a low-intensity shower for 2 min in 30 min intervals from 12 to 19 h (SHO group). Another group without showers was also considered (CON). Feeder occupancy measurement, thermographic measures, and carcass and meat quality parameters were studied. In the periods with higher environmental temperatures, SHO animals showed an increase in the feeder occupancy rate compared to the CON group. A decrease in temperature was observed after the shower, regardless of the anatomical location (p < 0.005). The treatment with showers led to higher values than in the CON group of 4.72%, 3.87%, 11.8%, and 15.1% for hot carcass weight, lean meat yield, and fat thickness in Longissimus Dorsi (LD) and Gluteus Medius muscles, respectively (p < 0.01). Pork from CON showed a 14.9% higher value of drip loss, and 18.9% higher malondialdehyde concentration than SHO (p < 0.01); meanwhile, intramuscular fat content was 22.8% higher in SHO than in CON (p < 0.01). On the other hand, the CON group exhibited higher L* (2.13%) and lower a* and b* values (15.8% and 8.97%) compared to the SHO group. However, the pH_20h of the CON group was significantly lower than that of the SHO group (p < 0.001), indicating a softer pH decrease. Related to fatty acids in subcutaneous outer and inner layers and intramuscular fat, the CON group showed higher ΣSFA and lower ΣMUFA and Δ₉-desaturase indexes than SHO (p < 0.05). In conclusion, the amelioration of heat stress through showers at critical times should be considered an interesting tool that improves both carcass and meat quality, as well as animal welfare. Full article

The quality of pork is significantly impacted by intramuscular fat (IMF). However, the regulatory mechanism of IMF depositions remains unclear. We performed whole-transcriptome sequencing of the longissimus dorsi muscle (IMF) from the high (5.1 ± 0.08) and low (2.9 ± 0.51) IMF groups (%) to elucidate potential mechanisms. In summary, 285 differentially expressed genes (DEGs), 14 differentially expressed miRNAs (DEMIs), 83 differentially expressed lncRNAs (DELs), and 79 differentially expressed circRNAs (DECs) were identified. DEGs were widely associated with IMF deposition and liposome differentiation. Furthermore, competing endogenous RNA (ceRNA) regulatory networks were constructed through co-differential expression analyses, which included circRNA-miRNA-mRNA (containing 6 DEMIs, 6 DEGs, 47 DECs) and lncRNA-miRNA-mRNA (containing 6 DEMIs, 6 DEGs, 36 DELs) regulatory networks. The circRNAs sus-TRPM7_0005, sus-MTUS1_0004, the lncRNAs SMSTRG.4269.1, and MSTRG.7983.2 regulate the expression of six lipid metabolism-related target genes, including PLCB1, BAD, and GADD45G, through the binding sites of 2-4068, miR-7134-3p, and miR-190a. For instance, MSTRG.4269.1 regulates its targets PLCB1 and BAD via miRNA 2_4068. Meanwhile, sus-TRPM7_0005 controls its target LRP5 through ssc-miR-7134-3P. These findings indicate molecular regulatory networks that could potentially be applied for the marker-assisted selection of IMF to enhance pork quality. Full article