Intramuscular Fat Content Research Articles

7. Development of an automatic method to estimate the intramuscular fat content of fattening pigs

7. Development of an automatic method to estimate the intramuscular fat content of fattening pigs

Transcriptomic analysis of different intramuscular fat contents on the flavor of the longissimus dorsi tissues from Guangling donkey

BackgroundIn this study, researchers aimed to explore the impact of intramuscular fat (IMF) concentration on the flavor of donkey meat, specifically in the longissimus dorsi muscle of Guangling donkeys. The internal volatile organic compounds that cause the flavor differences between donkey muscles are not clear at present. Transcriptomic technologies were utilized to analyze gene expression and its relationship to donkey meat flavor. MethodThirty Guangling donkeys had their IMF content evaluated in the longissimus dorsi muscle. Based on IMF content, 16 donkeys of similar ages were divided into two groups: low-fat (L) and high-fat (H). Headspace solid-phase microextraction Gas chromatography-mass spectrometry (HS-SPME-GC–MS) and headspace solid phase microextraction mass spectrometry were used to identify potential flavor components that differed between the two groups. ResultsFive key volatile substances were identified, and WGCNA and KEGG analysis was conducted to analyze the genes associated with these substances. The results showed that pathways like PPAR signaling, nucleotide excision repair, glucagon signaling, arachidonic acid metabolism, and glycolysis/glycogenesis were involved in lipid deposition. Additionally, a gene-gene interaction network map was constructed, highlighting the importance of hub genes such as EEF2, DDX49, GAP43, SNAP25, NDUFS8, MRPS11, RNASEH2A, POLR2E, POLR2C and ALB in regulating key flavor substances. ConclusionThis study provided valuable insights into the regulation of genes and protein expression related to flavor substances in donkey meat. It also deepened understanding of the influence of IMF on flavor and laid a foundation for future molecular breeding improvements in Guangling donkeys.

Dynamic alternations of three-dimensional chromatin architecture contribute to phenotypic characteristics of breast muscle in chicken

Breast muscle growth rate and intramuscular fat (IMF) content show apparent differences between fast-growing broilers and slow-growing indigenous chickens. However, the underlying genetic basis of these phenotypic characteristics remains elusive. In this study, we investigate the dynamic alterations of three-dimensional genome architecture and chromatin accessibility in breast muscle across four key developmental stages from embryo to starter chick in Arbor Acres (AA) broilers and Yufen (YF) indigenous chickens. The limited breed-specifically up-regulated genes (Bup-DEGs) are embedded in breed-specific A compartment, while a majority of the Bup-DEGs involving myogenesis and adipogenesis are regulated by the breed-specific TAD reprogramming. Chromatin loops allow distal accessible regions to interact with myogenic genes, and those loops share an extremely low similarity between chicken with different growth rate. Moreover, AA-specific loop interactions promote the expression of 40 Bup-DEGs, such as IGF1, which contributes to myofiber hypertrophy. YF-specific loop interactions or distal accessible regions lead to increased expression of 5 Bup-DEGs, including PIGO, PEMT, DHCR7, TMEM38B, and DHDH, which contribute to IMF deposition. These results help elucidate the regulation of breast muscle growth and IMF deposition in chickens.

LEP inhibits intramuscular adipogenesis through the AMPK signaling pathway invitro.

Leptin can indirectly regulate fatty-acid metabolism and synthesis in muscle invivo and directly in incubated muscle exvivo. In addition, non-synonymous mutations in the bovine leptin gene (LEP) are associated with carcass intramuscular fat (IMF) content. However, the effects of LEP on lipid synthesis of adipocytes have not been clearly studied at the cellular level. Therefore, this study focused on bovine primary intramuscular preadipocytes to investigate the effects of LEP on the proliferation and differentiation of intramuscular preadipocytes, as well as its regulatory mechanism in lipid synthesis. The results showed that both the LEP and leptin receptor gene (LEPR) were highly expressed in IMF tissues, and their mRNA expression levels were positively correlated at different developmental stages of intramuscular preadipocytes. The overexpression of LEP inhibited the proliferation and differentiation of intramuscular preadipocytes, while interference with LEP had the opposite effect. Additionally, LEP significantly promoted the phosphorylation level of AMPKα by promoting the protein expression of CAMKK2. Meanwhile, rescue experiments showed that the increasing effect of AMPK inhibitors on the number of intramuscular preadipocytes was significantly weakened by the overexpression of LEP. Furthermore, the overexpression of LEP could weaken the promoting effect of AMPK inhibitor on triglyceride content and droplet accumulation, and prevent the upregulation of adipogenic protein expression (SREBF1, FABP4, FASN, and ACCα) caused by AMPK inhibitor. Taken together, LEP acted on the AMPK signaling pathway by regulating the protein expression of CAMKK2, thereby downregulating the expression of proliferation-related and adipogenic-related genes and proteins, ultimately reducing intramuscular adipogenesis.

A Comparison of Three Camera Technology Predictions of Intramuscular Fat Percentage in F1 Wagyu

The prevalence of highly marbled cattle breeds, such as Wagyu, has increased in the US due to consumer demand for higher-quality beef. The ability to grade highly marbled carcasses accurately and consistently, particularly with quantifying intramuscular fat content for validation, remains a challenging task for the Wagyu beef industry. New camera grading technologies have been proposed by VIAS VBG 2000 (e+v Technology GmbH & Co. KG, 2021), Meat Image Japan (MIJ), and MasterBeef (MB) for Wagyu-influenced beef carcass assessment based on advanced image analysis. However, the intramuscular fat measurements of these camera technologies and the actual percent intramuscular fat (%IMF) in the longissimus at the 12/13th rib have yet to be investigated. Chilled carcasses (n = 173) from F1 Wagyu cattle were ribbed between the 12th and 13th ribs, and the left carcass sides were imaged with the E+V, MIJ, and MB cameras. Additionally, the marbling score was assigned by a team of 3 US Department of Agriculture (USDA) graders. Samples from the longissimus thoracis were collected, and the %IMF of the muscle was determined in triplicate. Linear regressions and descriptive statistics were done using JMP (Statistical Discovery, NC, USA) software. Camera fat-related measurements were linearly correlated, and R2 was calculated. The E+V camera had the highest %IMF predictability of all cameras (P < 0.0001) using the marbling score (R2 = 0.6450) estimate. The MIJ camera presented prediction accuracy between the other 2 technologies (P < 0.0001) of %IMF with identical R2 for fat percent and fat score estimates (R2 = 0.5952). The MB camera had the lowest predictability (P < 0.0001) of %IMF using the measured marbling score (R2 = 0.3269), marbling area (R2 = 0.3333), and marbling percent (R2 = 0.3269) estimates from the instrument. As technology advances, new technologies will provide alternative means for grading Wagyu-influenced carcasses. Additionally, these findings could aid the implementation of the USDA pilot program for remote carcass grading.

Correlated Responses to Selection for Intramuscular Fat on the Gut Microbiome in Rabbits.

Intramuscular fat (IMF) content is important for meat production and human health, where the host genetics and its microbiome greatly contribute to its variation. The aim of this study is to describe the consequences of the genetic modification of IMF by selecting the taxonomic composition of the microbiome, using rabbits from the 10th generation of a divergent selection experiment for IMF (high (H) and low (L) lines differ by 3.8 standard deviations). The selection altered the composition of the gut microbiota. Correlated responses were better distinguished at the genus level (51 genera) than at the phylum level (10 phyla). The H-line was enriched in Hungateiclostridium, Limosilactobacillus, Legionella, Lysinibacillus, Phorphyromonas, Methanosphaera, Desulfovibrio, and Akkermansia, while the L-line was enriched in Escherichia, Methanobrevibacter, Fonticella, Candidatus Amulumruptor, Methanobrevibacter, Exiguobacterium, Flintibacter, and Coprococcus, among other genera with smaller line differences. A microbial biomarker generated from the abundance of four of these genera classified the lines with 78% accuracy in a logit regression. Our results demonstrate different gut microbiome compositions in hosts with divergent IMF genotypes. Furthermore, we provide a microbial biomarker to be used as an indicator of hosts genetically predisposed to accumulate muscle lipids, which opens up the opportunity for research to develop probiotics or microbiome-based breeding strategies targeting IMF.

Exploring the Longissimus Muscle: Unraveling its Correlation with Meat Quality in Bos indicus and Crossbred Bulls.

This study investigated muscle tissue in Bos indicus and crossbred bulls to explain differences in meat quality traits. Carcass traits, meat quality parameters, and biochemical and molecular investigations of myofibrillar proteins are described. Methods for evaluating pH, intramuscular fat (IMF), meat color (L*, a*, b*), water losses, tenderness, and molecular biology assays have been outlined. Specific procedures detailing calibration, sample preparation, and data analysis for each method are described. These include techniques such as infrared spectroscopy for IMF content, objective tenderness assessment, and electrophoretic separation of MyHC isoforms. Color parameters were highlighted as potential tools for predicting beef tenderness, a crucial quality trait influencing consumer decisions. The study employed the Warner-Bratzler shear force (WBSF) method, revealing values of 4.68 and 4.23 kg for Nellore and Angus-Nellore (P < 0.01), respectively. Total cooking losses and biochemical analyses, including myofibril fragmentation index (MFI), provided insights into tenderness variations. Muscle fiber types, particularly myosin heavy chain (MyHC) isoforms, were investigated, with a notable absence of MyHC-IIb isoform in the studied Zebu animals. The relationship between MyHC-I and meat tenderness revealed divergent findings in the literature, highlighting the complexity of this association. Overall, the study provides comprehensive insights into the factors influencing meat quality in Bos indicus and crossbred (Bos taurus × Bos indicus) bulls, offering valuable information for the beef industry.

Bta-miR-330 promotes bovine intramuscular pre-adipocytes adipogenesis via targeting SESN3 to activate the Akt-mTOR signaling pathway

Consumers are more inclined to choose beef with a high intramuscular fat content (IMF), which regulated by lots of factors. It is very significant to find a miRNA that plays a key role in the accumulation of IMF. In our study, we found that bta-miR-330 was highly expressed in Japanese black cattle and differentially expressed at intramuscular pre-adipocytes differentiation processes. Furthermore, we transfected the bta-miR-330 mimic & inhibitor in intramuscular pre-adipocytes. The results showed that bta-miR-330 inhibits the proliferation but promotes the adipogenesis of intramuscular pre-adipocytes. Subsequently, our study showed that bta-miR-330 binds to SESN3, which inhibits the adipogenesis of intramuscular pre-adipocytes. Moreover, we established the mechanism that bta-miR-330 promotes the adipogenesis of intramuscular pre-adipocytes by targeting SESN3 to activate the Akt-mTOR signaling pathway. Overall, our results revealed that bta-miR-330-SESN3-Akt-mTOR axis plays an important role in adipogenesis of intramuscular pre-adipocytes, which provides a molecular basis for increasing IMF content in beef cattle.

Calpain 1 gene expression in liver tissue and the association of novel calpain 1 single-nucleotide polymorphisms (SNPs) with meat quality in Bali cattle

Abstract. Calpain 1 (CAPN1) is an enzyme that influences meat tenderization, and it is involved in post mortem proteolysis. The bovine CAPN1 gene was chosen as a candidate gene for DNA sequencing to identify novel single-nucleotide polymorphisms (SNPs) in exons 8–10 and assess their associations with meat quality in Bali cattle. In an analysis of 95 Bali cattle, two novel SNPs (g.5327C&gt;T and g.5959C&gt;T) were identified in exons and four novel SNPs (g.5534C&gt;T, g.5807A&gt;C, g.5857G&gt;A, and g.5869T&gt;C) were discovered in introns. Allelic frequency was evaluated, and Hardy–Weinberg equilibrium was found for all SNPs in Bali cattle. The marbling score and intramuscular fat content as determined by ultrasound were associated with g.5869T&gt;C and g.5959C&gt;T. g.5327C&gt;T was associated with pH and meat color in Bali cattle, whereas two other SNPs (g.5869T&gt;C and g.5959C&gt;T) were associated with Warner–Bratzler shear force and meat color. Furthermore, g.5869T&gt;C was associated with linolenic acid content, and g.5959C&gt;T with caprylic and linolenic acid levels. However, intronic SNPs (g.5534C&gt;T, g.5807A&gt;C, and g.5857G&gt;A) did not significantly affect meat quality in Bali cattle. Quantitative real-time PCR of liver tissue revealed that the mRNA expression of CAPN1 significantly differed (P&lt;0.05) among the CT, CC, and TT genotypes. The results suggest that genetic variability in loci within CAPN1 might be associated with meat quality in Bali cattle.

Regulatory Effects of 198-bp Structural Variants in the GSTA2 Promoter Region on Adipogenesis in Chickens.

Molecular breeding accelerates animal breeding and improves efficiency by utilizing genetic mutations. Structural variations (SVs), a significant source of genetic mutations, have a greater impact on phenotypic variation than SNPs. Understanding SV functional mechanisms and obtaining precise information are crucial for molecular breeding. In this study, association analysis revealed significant correlations between 198-bp SVs in the GSTA2 promoter region and abdominal fat weight, intramuscular fat content, and subcutaneous fat thickness in chickens. High expression of GSTA2 in adipose tissue was positively correlated with the abdominal fat percentage, and different genotypes of GSTA2 exhibited varied expression patterns in the liver. The 198-bp SVs regulate GSTA2 expression by binding to different transcription factors. Overexpression of GSTA2 promoted preadipocyte proliferation and differentiation, while interference had the opposite effect. Mechanistically, the 198-bp fragment contains binding sites for transcription factors such as C/EBPα that regulate GSTA2 expression and fat synthesis. These SVs are significantly associated with chicken fat traits, positively influencing preadipocyte development by regulating cell proliferation and differentiation. Our work provides compelling evidence for the use of 198-bp SVs in the GSTA2 promoter region as molecular markers for poultry breeding and offers new insights into the pivotal role of the GSTA2 gene in fat generation.

Transcriptome analysis reveals the effects of Schizochytrium sp. on the meat quality attributes of Tan lambs

Schizochytrium sp., a feed additive, positively affects the quality of animal meat. In this study, the molecular mechanisms through which dietary Schizochytrium sp. affects the meat quality characteristics of Tan lambs were investigated using transcriptomic techniques. The findings demonstrate that the lambs supplemented with Schizochytrium sp. had a larger loin eye area and a higher average daily gain and intramuscular fat content (P < 0.05). They also had lower drip loss (at 24 and 48 h) and shear force (P < 0.05). Further, 745 genes were differentially expressed between lambs supplemented with Schizochytrium and the control group. Moreover, KEGG pathway analysis showed that the ECM-receptor interaction pathway, which is related to muscle generation and intramuscular fat deposition, was significantly enriched in the lambs administered a diet containing Schizochytrium sp. Herein, we identified some pivotal genes linked to muscular system development and lipid metabolism. Thus, using Schizochytrium sp. may boost the meat quality of Tan lambs by modifying the expression of genes related to hub pathways. The results supply a new basis to determine the molecular mechanisms through which Schizochytrium sp. supplementation regulates the meat quality characteristics of sheep.

Influence of body fat tissue on outcomes in patients undergoing hepatectomy or liver transplantation.

The purpose of this study is to investigate potential associations between body fat composition and postoperative outcomes in patients with hepatectomy or liver transplantation. Three online databases, including Embase, PubMed, and the Cochrane Library, were thoroughly searched for literature describing the relationship between body fat composition and outcomes of patients with liver surgery from the start of each database to October 29, 2023. The Newcastle-Ottawa Scale was used to rate the quality of the studies. This analysis included a total of 29 articles with a combined patient cohort of 6,435 individuals. The results demonstrated that patients with high intramuscular fat content (IMFC) had significantly inferior OS (HR: 2.07, 95% CI: 1.69-2.53, P < 0.001) and RFS (HR: 1.61, 95% CI: 1.20-2.16, P = 0.002) and a higher risk of major complications (HR: 2.20, 95% CI: 1.59-3.05, P < 0.001). We also found that the presence of high visceral-to-subcutaneous fat tissue ratio (VSR) in patients with liver surgery was significantly related to poorer OS (HR: 1.70, 95% CI: 1.44-2.00, P < 0.001) and PFS (HR: 1.29, 95% CI: 1.11-1.50, P = 0.001) and a higher major complication rate (HR: 2.31, 95% CI: 1.17-4.56, P = 0.016). Besides, the synthesized findings indicated there is no significant correlation between visceral fat tissue and survival outcomes or postoperative complications. In summary, preoperative IMFC and VSR have the potential to forecast poorer OS and RFS and a higher risk of complications for patients undergoing hepatectomy or liver transplantation.

Research Note: Basic chemical composition, physicochemical, and textural characteristics of male and female guinea fowl meat

The purpose of this study was to compare analyze the quality of meat depending on the type of muscle: breast muscles (m. Pectoralis superficialis and m. Pectoralis profundus) and leg muscles (m. Sartorius and m. Femorotibialis) in relation to the sex of the common guinea fowl (Numida meleagris). For the study, pectoral muscles and leg muscles from 10 females and 10 males at 20 wk of age were used to determine their chemical composition, physicochemical properties, and texture characteristics of the pectoral muscle were determined. Overall, pectoral muscles were characterized by higher protein content, lightness (L*), and electrical conductivity (EC24), and lower redness (a*), and pH24 compared to leg muscles. Leg muscles, on the other hand, were characterized by higher, collagen, intramuscular fat and salt content. In terms of pectoral muscle texture characteristics, males were characterized by lower chewiness value and were less gumminess. In conclusion, it can be said that the sex of the birds affected some of the pectoral muscle texture traits, but did not affect the remaining analyzed features of the pectoral and leg muscles. However, from the consumer's point of view, breast muscles contained more protein and less fat, so they are more dietary compared to leg muscles.

Metabolic and microbial mechanisms related to the effects of dietary wheat levels on intramuscular fat content in finishing pigs

The current study aimed to investigate the metabolic and microbial mechanisms behind the effects of dietary wheat levels on intramuscular fat (IMF) content in the psoas major muscle (PM) of finishing pigs. Thirty-six barrows were arbitrarily assigned to two groups and fed with diets containing 25% or 55% wheat. Enhancing dietary wheat levels led to low energy states, resulting in reduced IMF content. This coincided with reduced serum glucose and low-density lipoprotein cholesterol levels. The AMP-activated protein kinase α2/sirtuin 1/peroxisome proliferator-activated receptor-γ coactivator 1α pathway may be activated by high-wheat diets, causing downregulation of adipogenesis and lipogenesis genes, and upregulation of lipolysis and gluconeogenesis genes. High-wheat diets decreased relative abundance of Lactobacillus and Coprococcus, whereas increased SMB53 proportion, subsequently decreasing colonic propionate content. Microbial glycolysis/gluconeogenesis, d-glutamine and D-glutamate metabolism, flagellar assembly, and caprolactam degradation were linked to IMF content. Metabolomic analysis indicated that enhancing dietary wheat levels promoted the protein digestion and absorption and affected amino acids and lipid metabolism. Enhancing dietary wheat levels reduced serum glucose and colonic propionate content, coupled with strengthened amino acid metabolism, contributing to the low energy states. Furthermore, alterations in microbial composition and propionate resulted from high-wheat diets were associated with primary bile acid biosynthesis, arachidonic acid metabolism, steroid hormone biosynthesis, and biosynthesis of unsaturated fatty acids, as well as IMF content. Colonic microbiota played a role in reducing IMF content through modulating the propionate-mediated peroxisome proliferators-activated receptor signaling pathway. In conclusion, body energy and gut microbiota balance collectively influenced lipid metabolism.

Single-nucleus RNA sequencing and lipidomics reveal characteristics of transcriptional and lipid composition in porcine longissimus dorsi muscle

BackgroundGlobal per capita meat consumption continues to rise, especially pork. Meat quality is influenced by the content of intramuscular fat (IMF) as a key factor. The longissimus dorsi muscle of Dahe pigs (DHM, IMF: 7.98% ± 1.96%) and Dahe black pigs (DHBM, IMF: 3.30% ± 0.64%) was studied to explore cellular heterogeneity and differentially expressed genes (DEGs) associated with IMF deposition using single-nucleus RNA sequencing (snRNA-seq). The lipid composition was then analyzed using non-targeted lipidomics.ResultsA total of seven cell subpopulations were identified, including myocytes, fibroblast/fibro/adipogenic progenitors (FAPs), satellite cells, endothelial cells, macrophages, pericytes, and adipocytes. Among them, FAPs and adipocytes were more focused because they could be associated with lipid deposition. 1623 DEGs in the FAPs subpopulation of DHBM were up-regulated compared with DHM, while 1535 were down-regulated. These DEGs enriched in the glycolysis/gluconeogenesis pathway. 109 DEGs were up-regulated and 806 were down-regulated in the adipocyte subpopulation of DHBM compared with DHM, which were mainly enriched in the PPAR signaling pathway and fatty acid (FA) biosynthesis. The expression level of PPARG, ABP4, LEP, and ACSL1 genes in DHM was higher than that in DHBM. Lipidomics reveals porcine lipid composition characteristics of muscle tissue. A total of 41 lipid classes and 2699 lipid species were identified in DHM and DHBM groups. The top ten relative peak areas of lipid classes in DHM and DHBM were triglyceride (TG), phosphatidylcholine (PC), phosphatidylethanolamine (PE), phosphatidylserine (PS), diglyceride (DG), cardiolipin (CL), ceramides (Cer), Simple Glc series (Hex1Cer), sphingomyelin (phSM), and phosphatidylinositol (PI). The relative peak areas of 35 lipid species in DHM were lower than DHBM, and 28 lipid species that were higher. There was a significant increase in the TG fatty acyl chains C6:0, C17:0, and C11:4, and a significant decrease in C16:0, C18:1, C18:2, and C22:4 in DHBM (p < 0.05).ConclusionsC16:0 FA may downregulate the expression level of PPARG gene, which leads to the downregulation of fat metabolism-related genes such as ACSL, PLIN2, and FABP4 in DHBM compared with DHM. This may be the reason that the lipid deposition ability of Dahe pigs is stronger than that of Dahe black pigs, which need further investigation.

Continued development of a tool to measure intramuscular fat of Australian lamb carcases in commercial situations

Despite the importance of intramuscular fat (IMF) to eating quality, as yet no methodology has been widely adopted by the whole of industry in Australia to measure it routinely. Thus, a study was conducted to investigate the potential for a Near Infra-Red (NIR) device to predict the IMF content of the loin from spectra collected on the topside which is externally located on a hanging carcase and therefore easily accessible. To this end, NIR spectra were collected from topsides (m. semimembranosus) of 258 lamb carcases over 5 data collections and a sample of muscle was collected from the loin and the topside for IMF determination using a wet chemistry method. Subsequent Partial Least Square (PLS) models suggested the ability to predict the absolute IMF content of loins was poor (R2 = 0.28, RMSE = 1.26), yet there was a moderate ability to predict the IMF content of the topside (R2 = 0.56, RMSE = 0.82). Partial Least Square Discrimination Analysis (PLS-DA) models to classify cuts based on the IMF eating quality threshold of 4.5% yielded better predictive outcomes with accuracies of 66.7% and 76.7% for loin and topside respectively. However, further research to assess the relationship between the IMF of the loin and topside and reduce the impact of differences in overall absorbance between data collections will improve predictive outcomes.

Preliminary studies on the molecular mechanism of intramuscular fat deposition in the longest dorsal muscle of sheep

BackgroundIntramuscular fat content is an important index reflecting the quality of mutton, which directly affects the flavor and tenderness of mutton. Livestock and poultry intramuscular fat content is influenced by genetics, nutritional level, and environmental factors. Key regulatory factors play a crucial role in intramuscular fat deposition. However, there is a limited amount of research on the identification and function of key genes involved in intramuscular fat content deposition specifically in sheep.ResultsHistological differences in the longest dorsal muscle of the small-tailed frigid sheep increased in diameter and decreased in several muscle fibers with increasing monthly age; The intramuscular fat content of the longest dorsal muscle of the small-tailed cold sheep varied with age, with a minimum of 1 month of age, a maximum of 6 months of age, and a minimum of 12 months of age. Transcriptomic sequencing and bioinformatics analysis revealed a large number of differential genes in the longest dorsal muscles of little-tailed billy goats of different months of age, which were enriched in multiple GO entries and KEGG pathways. Among them, the pathway associated with intramuscular fat was the AMPK signaling pathway, and the related genes were PPARGC1A and ADIPOQ; Immunohistochemical studies showed that PPARGC1A and ADIPOQ proteins were expressed in connective tissues, cell membranes, and, to a lesser extent, the cytoplasm of the longest dorsal muscle of the little-tailed frigid sheep; Real-time PCR and Western Blot validation showed that PPARGC1A and ADIPOQ were both expressed in the longest dorsal muscle of the little-tailed frigid sheep at different ages, and there were age differences in the amount of expression. The ADIPOQ gene was negatively correlated with the intramuscular fat content of the longest dorsal muscle, and the PPARGC1A gene was positively correlated with the intramuscular fat content of the longest dorsal muscle; As inferred from the above results, the ADIPOQ gene was negatively correlated with the intramuscular fat content of the longest dorsal muscle (r = -0.793, P < 0.05); and the PPARGC1A gene was positively correlated with the intramuscular fat content of the longest dorsal muscle r = 0.923, P < 0.05).ConclusionsBased on the above results, it can be inferred that the ADIPOQ gene is negatively correlated with the intramuscular fat content of the longest back muscle (r = -0.793, P < 0.05); the PPARGC1A gene is positively correlated with the intramuscular fat content of the longest back muscle (r = 0.923, P < 0.05).

Temporal Transcriptome Dynamics of Longissimus dorsi Reveals the Mechanism of the Differences in Muscle Development and IMF Deposition between Fuqing Goats and Nubian Goats.

In this study, we measured the growth performance and intramuscular fat (IMF) content of the Longissimus dorsi (LD) of Fuqing goats (FQs) and Nubian goats (NBYs), which exhibit extreme phenotypic differences in terms of their production and meat quality traits. RNA-Seq analysis was performed, and transcriptome data were obtained from the LD tissue of 3-month fetuses (E3), 0-month lambs (0M), 3-month lambs (3M), and 12-month lambs (12M) to reveal the differences in the molecular mechanisms regulating the muscle development and IMF deposition between FQs and NBYs. The results showed that a higher body weight and average daily gain were observed in the NBYs at three developmental stages after birth, whereas a higher IMF content was registered in the FQs at 12M. Additionally, transcriptome profiles during the embryonic period and after birth were completely different for both FQs and NBYs. Moreover, DEGs (KIF23, CCDC69, CCNA2, MKI67, KIF11, RACGAP1, NUSAP1, SKP2, ZBTB18, NES, LOC102180034, CAPN6, TUBA1A, LOC102178700, and PEG10) significantly enriched in the cell cycle (ko04110) at E3 (FQs vs. NBYs), and DEGs (MRPS7, RPS8, RPL6, RPL4, RPS11, RPS10, RPL5, RPS6, RPL8, RPS13, RPS24, RPS15, RPL23) significantly enriched in ribosomes (ko03010) at 0M (FQs vs. NBYs) related to myogenic differentiation and fusion were identified. Meanwhile, the differences in glucose and lipid metabolism began at the E3 timepoint and continued to strengthen as growth proceeded in FQs vs. NBYs. DEGs (CD36, ADIROQR2, ACACA, ACACB, CPT1A, IGF1R, IRS2, LDH-A, PKM, HK2, PFKP, PCK1, GPI, FASN, FADS1, ELOVL6, HADHB, ACOK1, ACAA2, and ACSL4) at 3M (FQs vs. NBYs) and 12M (FQs vs. NBYs) significantly enriched in the AMPK signaling pathway (ko04152), insulin resistance (ko04931), the insulin signaling pathway (ko04910), fatty acid metabolism (ko01212), and glycolysis/gluconeogenesis (ko00010) related to IMF deposition were identified. Further, the results from this study provide the basis for future studies on the mechanisms regulating muscle development and IMF deposition in different breeds of goats, and the candidate genes identified could be used in the selection process.

Unraveling the Genetic Foundations of Broiler Meat Quality: Advancements in Research and Their Impact.

As societal progress elevates living standards, the focus on meat consumption has shifted from quantity to quality. In broiler production, optimizing meat quality has become paramount, prompting efforts to refine various meat attributes. Recent advancements in sequencing technologies have revealed the genome's complexity, surpassing previous conceptions. Through experimentation, numerous genetic elements have been linked to crucial meat quality traits in broiler chickens. This review synthesizes the current understanding of genetic determinants associated with meat quality attributes in broilers. Researchers have unveiled the pivotal insights detailed herein by employing diverse genomic methodologies such as QTL-based investigations, candidate gene studies, single-nucleotide polymorphism screening, genome-wide association studies, and RNA sequencing. These studies have identified numerous genes involved in broiler meat quality traits, including meat lightness (COL1A2 and ACAA2), meat yellowness (BCMO1 and GDPD5), fiber diameter (myostatin and LncIRS1), meat pH (PRDX4), tenderness (CAPN1), and intramuscular fat content (miR-24-3p and ANXA6). Consequently, a comprehensive exploration of these genetic elements is imperative to devise novel molecular markers and potential targets, promising to revolutionize strategies for enhancing broiler meat quality.

A Study on Changes of Carcass, Bones and Muscles of Ningxiang Pigs

Background: Ningxiang pigs are known for tasty meat and high intramuscular fat content. Currently, the slow growth rate and low lean meat rate of Ningxiang pigs have greatly restricted the development of its market. Therefore, the objective of this study is to explore the changes in carcass traits, meat quality, visceral organ weight indices, bones and muscles development with slaughter ages of Ningxiang pigs. Methods: The experiment used 0, 60, 120, 180, 240, 300 and 360 days old Ningxiang pigs as the research objects, and 6 castrated male pigs in each group were randomly selected. The carcass traits, meat quality, visceral organs weights and skeletal muscle weights were measured. The correlation between carcass traits and meat quality were analyzed by bivariate analysis, and the regression equations between slaughter ages and these indicators were established. Result: The results showed that pre-slaughter weight and weights of carcass, head, feet, skeleton and muscle, loin eye area, cooking yield, marbling and the large intestine weight index at 0 d, backfat thickness at 60 d, fat percentages at 60 and 120 d, and the lean meat percentage at 240 d, redness at 120 d of Ningxiang pigs were lowest, the heart, lung, kidney and small intestine weight percentages were highest at 0 d (P less than 0.05). Carcass traits and meat quality had different significant correlation at different slaughter ages. So the indices of carcass, meat quality, bones and muscles of Ningxiang pigs changed with slaughter ages. In general, the overall performance of 300 d Ningxiang pigs is better.