Intramuscular Fat Content Research Articles

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 alternate 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 200-300bp. 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.

Nutritional Processing Quality of Sika Deer (Cervus nippon) Venison in Different Muscles.

In order to investigate the nutritional processing quality of sika deer (Cervus nippon) venison at different sites, the pH24 h, tenderness, pressurized water loss rate, meat color, intramuscular fat, moisture, protein, amino acid, fatty acid and squalene contents of sika deer venison were determined in twelve sites: foreleg, hind leg, outer tenderloin, rump, neck meat, chest meat, deer flank, abdominal rib, high rib, tenderloin, anterior tendon and posterior tendon. The results showed that the pH24 h of sika deer venison at different sites was 5.49~5.78; the tenderness of outer tenderloin (31.71 N) was the lowest, and the neck meat (68.53 N) was the highest; the squeezing moisture of tenderloin (28.12%) was the largest, and the foreleg (12.34%) was the smallest; the brightness of outer tenderloin L* (29.68) was the lowest, and the redness a* and yellowness b* of deer flank were the highest; the intramuscular fat and moisture were 0.66~4.97% and 71.00~73.78%, respectively; and the protein content of outer tenderloin (23.44%) and rump (24.02%) was high. The venison meat contained 17 kinds of amino acids, and the total amount was 63.87~79.33 g/100 g. It was rich in essential amino acids, mainly lysine and leucine, accounting for 64.29~65.39% of non-essential amino acids, which was close to the ideal protein composition. Palmitoleic acid and oleic acid were the main monounsaturated fatty acids in venison, and the contents of abdominal ribs were the highest, 16,875.33 mg/kg and 31,772.73 mg/kg, respectively. The contents of essential fatty acids were also the highest in abdominal ribs (11,225.37 mg/kg); forelegs, hind legs, outer tenderloins, rumps, neck meat, chest meat, high rib, tenderloins, anterior tendons and posterior tendons were all good sources of polyunsaturated fatty acids. Squalene content was highest in the abdominal rib (100.85 mg/kg). The nutritional processing quality of sika deer venison in different muscles is significantly different, and this study can provide a data basis for the evaluation and processing of sika deer venison quality.

Caecal metabolomics of two divergently selected rabbit lines revealed microbial mechanisms correlated to intramuscular fat deposition.

The gastrointestinal microbiota plays a key role in the host physiology and health through a complex host-microbiota co-metabolism. Metabolites produced by microbial metabolism can travel through the bloodstream to reach distal organs and affect their function, ultimately influencing the development of relevant production traits such as meat quality. Meat quality is a complex trait made up of a number of characteristics and intramuscular fat content (IMF) is considered to be one of the most important parameters. In this study, 52 rabbits from two lines divergently selected for IMF (high-IMF (H) and low-IMF (L) lines) were used to perform an untargeted metabolomic analysis of their caecal content, with the aim to obtain information on genetically determined microbial metabolism related to IMF. A large, correlated response to selection was found in their caecal metabolome composition. Partial least squares discriminant analysis was used to identify the pathways differentiating the lines, which showed a classification accuracy of 99%. On the other hand, two linear partial least squares analyses were performed, one for each line, to extract evidence on the specific pathways associated with IMF deposition within each line, which showed predictive abilities (estimated using the Q2) of approximately 60%. The most relevant pathways differentiating the lines were those related to amino acids (aromatic, branched-chain and gamma-glutamyl), secondary bile acids, and purines. The higher content of secondary bile acids in the L-line was related to greater lipid absorption, while the differences found in purines suggested different fermentation activities, which could be related to greater nitrogen utilisation and energy efficiency in the L-line. The linear analyses showed that lipid metabolism had a greater relative importance for IMF deposition in the L-line, whereas a more complex microbial metabolism was associated in the H-line. The lysophospholipids and gamma-glutamyl amino acids were associated with IMF in both lines; the nucleotide and secondary bile acid metabolisms were mostly associated in the H-line; and the long-chain and branched-chain fatty acids were mostly associated in the L-line. A metabolic signature consisting of two secondary bile acids and two protein metabolites was found with 88% classification accuracy, pointing to the interaction between lipid absorption and protein metabolism as a relevant driver of the microbiome activity influencing IMF.

Glutamate increases the lean percentage and intramuscular fat content and alters gut microbiota in Shaziling pigs

This study aimed to explore the effects of glutamate (Glu) supplementation on the growth performance, carcass traits, meat quality, composition of amino acids and fatty acids in the longissimus dorsi muscle, and the colonic microbial community of Shaziling pigs. A total of 48 healthy male Shaziling pigs (150 d, 31.56 ± 0.95 kg) were randomly assigned to two groups, and fed a basal diet with no supplement (control group) or supplemented with 1% Glu (Glu group) for 51 d, and 6 pigs per group were finally slaughtered. Glu significantly increased the average daily gain (P = 0.039), lean percentage (P = 0.023), and intramuscular fat (IMF) content (P = 0.015), and decreased the fat percentage (P = 0.021) of Shaziling pigs. In the muscle, Glu increased the concentrations of inosine-5’-monophosphate (P = 0.094), Fe (P = 0.002), Cu (P = 0.052), and monounsaturated fatty acids (MUFAs) (P = 0.024), and decreased the content of C18:2n6 (P = 0.011), n6 polyunsaturated fatty acids (n6 PUFAs) (P = 0.014), and PUFAs (P = 0.014). Moreover, Glu significantly upregulated the mRNA expression of adipogenesis-related genes (FAS, SREBP-1C) (P = 0.032, P = 0.026) and muscle growth-related genes (MyHCⅡb, MyHCⅡx) (P = 0.038, P = 0.019) in the muscle, and increased the relative abundance of Spirochaetota (P < 0.001) and the acetic acid content in the colon (P = 0.039). Correlation analysis indicated that the acetic acid content was positively correlated with the relative Spirochaetota abundance and the IMF content, and a negative trend with the fat percentage of Shaziling pigs. In conclusion, these results indicated that Glu could simultaneously increase the lean percentage and IMF content and decrease the fat percentage of Shaziling pigs, and these beneficial effects may be related to increased colonic Spirochaetota abundance and acetic acid concentrations.

Core promoter identification and transcriptional regulation of porcine ACSL3 gene.

Intramuscular fat (IMF) content is an important factor that affects the edible and processing quality of pork. Studying the transcriptional regulation mechanisms of genes affecting intramuscular fat deposition can provide theoretical support for genetic improvement in pigs. Long-chain fatty acyl-CoA synthase 3 (ACSL3), as a key enzyme in the process of lipid synthesis in mammals. However, no information about the core promoter of the ACSL3 gene and its transcriptional regulation has been reported so far. In this experiment, we successfully cloned 3112 bp of the porcine ACSL3 gene promoter region. In order to find out the core promoter of the ACSL3 gene. The results indicated that the core promoter region of the ACSL3 gene is located from -111 bp to -59 bp upstream of the transcription initiation site (TSS). To identify the interaction between SP1 and the ACSL3 gene promoter, we mutated the predicted binding sites of ACSL3 gene promoter. The results showed that the activity of the promoter was decreased by site-specific mutagenesis of the SP1 transcription factor binding site, while overexpression of SP1 increased the expression of the ACSL3 gene. In summary, our study identified a core promoter region of the porcine ACSL3 gene, and the SP1 binding site is responsible for the promoter activity.

Epigenetic insights into creep-feeding: methylation profiling of Longissimus thoracis muscle at weaning in crossbred cattle

IntroductionThis study investigated the impact of creep-feeding supplementation on the genome methylation of the Longissimus thoracis (LT) muscle in crossbred beef cattle (Bos taurus × Bos indicus).MethodsThe experiment involved 48 uncastrated F1 Angus-Nellore males (half-siblings), which were divided into two groups: NCF – no creep-feeding (n = 24) and CF – creep-feeding (n = 24). After weaning at 210 days, all animals were feedlot finished for 180 days under identical conditions. LT muscle biopsies were collected at weaning for genomic DNA methylation analysis by reduced representation bisulfite sequencing (RRBS).Results and discussionThe groups differed significantly (CF &amp;gt; NCF: p &amp;lt; 0.05) to weaning weight (243.57±5.70 vs. 228.92±5.07kg), backfat thickness (12.96±0.86 vs. 10.61±0.42mm), LT muscle marbling score (366.11±12.39 vs. 321.50±13.65), and LT intramuscular fat content (5.80±0.23 vs. 4.95±0.20%). The weights at the beginning of the experiment and at slaughter (390 days) did not differ significantly. Mean methylation levels were higher in CF with 0.18% more CpG, 0.04% CHG, and 0.03% CHH. We identified 974 regions with differential methylation (DMRs: &amp;gt; 25% and q &amp;lt; 0.05), which overlapped with 241 differentially methylated genes (DMGs). Among these genes, 108 were hypermethylated and 133 were hypomethylated in CF group. Notably, 39 of these DMGs were previously identified as differentially expressed genes (DEGs: log2 fold change [0.5]) in the same animal groups. Over-representation analysis highlighted epigenetic regulations related to muscle growth, PPAR signaling, adipogenesis, insulin response, and lipid metabolism. Key DMGs/DEGs included: ACAA1, SORBS1, SMAD3, TRIM63, PRKCA, DNMT3A, RUNX1, NRG3, and SLC2A8. These epigenetic changes improved the performance of supplemented animals up to weaning and enhanced meat quality traits, particularly higher intramuscular fat. The results provided insights into the intricate interplay between nutrition, epigenetics, gene expression and phenotypes in beef cattle production.

Copy Number Variation and Selection Signal: Exploring the Domestication History and Phenotype Differences Between Duroc and the Chinese Native Ningxiang Pigs.

The Ningxiang pig, one of the well-known Chinese native pig breeds, has the advantages of tender meat, high intramuscular fat (IMF) content, and roughage tolerance, compared to the commercial lean pig breeds. The genetic basis for complex traits in Ningxiang pigs has been previously studied through other genetic markers, such as Single Nucleotide Polymorphism (SNP), while the characteristics of copy number variation (CNV) and the selection signal have not been investigated yet. In this study, GGP 50 k genotyping data of 2242 Ningxiang pigs (NX) and 1137 Duroc pigs (Duroc) were involved in CNV atlas construction and selection signals identification. Annotations of genes and quantitative trait locus (QTLs) were performed on the target candidate regions, as follows: (1) 162 CNVs were detected in Ningxiang pigs, while 326 CNVs were detected in Duroc pigs, and there are 21 copy number variation regions (CNVRs) shared between them; (2) The CNVRs of Duroc are more abundant, with 192 CNVRs, accounting for 1.61% of the entire genome, while those of Ningxiang pigs only have 98 CNVRs, accounting for 0.49%; (3) The QTLs annotated on CNVs and selected regions of Ningxiang pigs were mainly associated with meat quality and fertility. In contrast, the Duroc QTLs' notes relate primarily to the carcass and immunity, and explain why they have a higher slaughter rate and immunity; (4) There is a presence of high-frequency acquired CNVs, specifically in Ningxiang pigs, with 24 genes significantly enriched in the sensory receptor-related pathway in this region; (5) Based on the CNVs atlas, candidate genes such as 3 inositol 1,4,5-triphosphate receptor, type 3 (ITPR3), forkhead box protein K2 (FOXK2), G-protein coupled estrogen receptor 1 (GPER1), Glyceraldehyde 3-phosphate dehydrogenase (GAPDH), triosephosphate isomerase 1 (TPI1), and other candidate genes related to fat deposition and differentiation were screened. In general, this study improved our knowledge about copy number variation and selection signal information of Ningxiang pigs, which can not only further explain the genetic differences between Chinese native and Western commercial pig breeds, but also provide new materials for the analysis of the genetic basis of complex traits.

The liveweight, carcasses and meat quality of intact and castrated male lambs reared under a pasture-fed Australian production system

Context Intact male (ram) lambs are often discounted by meat processors because of their perceived defective meat quality. Aims This study quantified the effects of castration on the liveweight, growth, carcass parameters and the meat quality of male lambs. Methods Liveweight, growth and carcass data were collected from 133 ram and 132 castrated (wether) lambs reared under a pasture-fed production system. A total of 50 lambs were subsequently selected, balanced by final curfew liveweight and castration status, to investigate additional carcass, meat quality, consumer sensory panel scores and colour stability parameters. Key results It was found that total average daily gains for ram lambs were highest (242.9 ± 5.2 g/day; P = 0.002), resulting from their higher pre-weaning growth rate of 327.7 ± 9.7 g/day (P &lt; 0.001). Wethers were fattier, having higher estimated intramuscular fat (3.9 vs 3.3 ± 0.1%, respectively) and subcutaneous fat depth (14.7 vs 13.5 ± 0.4 mm, respectively) than ram lambs. Purge loss (P &lt; 0.030) and ultimate pH (P &lt; 0.035) were higher for the meat of wether lambs, but only after 32 days of wet ageing. Consumers scored the meat of wether lambs as significantly more tender (61.0 vs 54.6 ± 2.3%; P = 0.005) and of greater overall liking (65.1 vs 61.1 ± 2.0%; P = 0.044) than that of ram lambs. These, and a comparison of shear force, near infrared spectroscopy for intramuscular fat content and retail colour with consumer thresholds, suggest a general satisfaction with ram and wether lamb meat quality. Conclusions Collectively, there seems to be few tangible performance and meat quality advantages to the castration of male lambs. Implications Prime lamb producers must consider flock management and market preference when deciding on best practice.

Investigation into Critical Gut Microbes Influencing Intramuscular Fat Deposition in Min Pigs.

To determine the pivotal microorganisms affecting intramuscular fat (IMF) accumulation in Min pigs and to discern the extent of the influence exerted by various intestinal segments on IMF-related traits, we sequenced 16S rRNA from the contents of six intestinal segments from a high IMF group (Group H) and a low IMF group (Group L) of Min pigs weighing 90 ± 1 kg. We then compared their diversity and disparities in bacterial genera. Group H exhibited considerably higher α diversity in the jejunum and colon than Group L (p < 0.05). When 95% confidence levels were considered, the main β diversity components for the ileum, caecum, and colon within Groups H and L exhibited absolute segregation. Accordingly, 31 differentially abundant genera across Group H were pinpointed via LEfSe and the Wilcoxon test (p < 0.05) and subsequently scrutinised based on their distribution and abundance across distinct intestinal segments and their correlation with IMF phenotypes. The abundances of Terrisporobacter, Acetitomaculum, Bacteroides, Fibrobacter, Treponema, Akkermansia, Blautia, Clostridium sensu stricto 1, Turicibacter, Subdoligranulum, the [Eubacterium] siraeum group, and dgA 11 gut groups were positively correlated with IMF content (p < 0.05), whereas those of Bacillus, the Lachnospiraceae NK4A136 group, Streptococcus, Roseburia, Solobacterium, Veillonella, Lactobacillus, the Rikenellaceae RC9 gut group, Anaerovibrio, and the Lachnospiraceae AC2044 group were negatively associated with IMF content (p < 0.05). Employing PICRUSt2 for predicting intergenic metabolic pathways that differ among intestinal microbial communities revealed that within the 95% confidence interval the colonic microbiome was enriched with the most metabolic pathways, including those related to lipid metabolism. The diversity results, bacterial genus distributions, and metabolic pathway disparities revealed the colonic segment as an influential region for IMF deposition.

4D DIA proteomic analysis of gender and age influences on meat quality and flavor in Hetian white sheep

To investigate the impact of age and gender on mutton flavor and quality, we analyzed mutton from 12-month-old and 6-month-old rams and ewes. The results indicated that 12 months Hetian white sheep exhibited higher levels of amino acids, protein, free fatty acids, and reducing sugars compared to 6-months. Additionally, amino acid, protein, and reducing sugar levels were higher in ewes than 12 months rams. Proteomic analysis revealed that proteins related to fatty acid metabolism, intramuscular fat (IMF), and mitochondrial function were more abundant in ram. The upregulation proteins involved in amino acid metabolism in ewes highlights its richer flavor profile compared to ram. Proteins associated with muscle development and mitochondrial activity were more highly expressed in the 12-month-old samples compared to those from 6-month-old sheep. ECI1, highly expressed in rams, is linked to IMF content. We hypothesize that ECI1 may serve as a potential protein marker for mutton quality.

Transcriptome and targeted metabolome analysis of lipid profiles, nutrients compositions and volatile compounds in longissimus dorsi of different pig breeds.

Improving meat quality is important for commercial production and breeding. The molecular mechanism of intramuscular fat (IMF) deposition and meat characteristics remain further study. This study aimed to study the mechanism of IMF deposition and meat characteristics including redox potential, nutrients compositions and volatile compounds in longissimus dorsi (LD) by comparing with different pig breeds including Shanghai white (SW), Duroc x (Landrace Yorkshire) (DLY) and Laiwu (LW) pigs. Results showed that the contents of IMF, triglyceride (TG), total cholesterol (TC), and redox potential parameters were lower, while the content of MDA and activity of lactate dehydrogenase (LDH) were higher in LD of SW pigs compared with LW pigs (p<0.05). No differences were observed about these parameters between SW and DLY pigs. Also, the contents of medium-long chain fatty acids and γ-aminobutyric acid (GABA) were higher, while Asp was lower in LD of SW pigs compared with LW pigs (p<0.05). Volatile compounds results showed that 6 ketones, 4 alkenes, 11 alkanes, 2 aldehydes, 1 alcohol were increased and cholesterol was decreased in SW pigs compared with LW pigs. Transcriptome results showed that differential expressed genes involved in lipid synthesis, metabolism and transport in LD between SW and LW pigs, which were further verified by qPCR. Spearman correlation showed that HSL and Nedd4 were positively related to contents of TG and IMF, while negatively related to volatile compounds and fatty acids (p<0.05). Plin3 and Mgll were negatively related to contents of TG, IMF and cholesterol, while positively related to MDA, LDH, and volatile compounds (p<0.05). PPARA was negatively related to contents of TC and IMF, and activity of SOD, while positively related to volatile compounds (p<0.05). Our study provided new insights into potential mechanisms of IMF deposition, nutrients composition and volatile compounds of muscular tissues of different pig breeds.

Composition of Donkey Meat (Equus Asinus) from the Puno Region, Peru

Objective: To determine the proximate chemical composition of donkey meat (Equus asinus) considering the variables of animal class (young and adult) and commercial cut (shoulder, rib and leg) with the purpose of nutritionally assessing it as an alternative source of red meat. Theoretical Framework: Donkey meat is characterized by a low intramuscular fat content and could be used as a valid alternative to other species of red meat such as beef and sheep in the Puno region, Peru. However, little is known about the nutritional quality of meat from donkeys that are slaughtered at the main equine slaughterhouse in southern Peru. Method: Muscle tissue samples were taken from the following muscles: deltoid, Longissimus dorsi and biceps femoris representing the commercial cuts of shoulder, rib and leg, respectively. Chemical analysis (moisture, protein, fat and ash) was performed following the protocols established for meat by the Association of Official Analytical Chemists (AOAC), in the Bromatology Laboratory of the Faculty of Veterinary Medicine and Zootechnics of UNA-Puno. Data analysis was performed in a randomized complete block design (DBCA) and the LSD significance test (α=0.05). Results and Discussion: The proximate chemical composition of donkey meat is as follows: moisture 73.79%, protein 19.23%, fat 4.53% and ash 1.20%. The animal class (young and adult) and the commercial cut (shoulder, rib and leg) have a significant effect on the moisture and fat content (p≤0.05), with an inverse relationship between the two; but there is no effect on the protein and ash content (p&gt;0.05). Implications of the research: It was possible to demonstrate that the meat of donkeys from the Puno region has a similar composition to the red meat of other domestic species, so it can be a good alternative to replace red meat. Originality/Value: This study contributes to the literature by knowing the chemical composition of donkey meat from the Puno region, Peru for consumption purposes as a substitute for red meat or for the preparation of meat by-products.

High-concentrate diet supplemented with hydrolysable tannin improves the slaughter performance, intestinal antioxidant ability and barrier function of fattening lambs.

The objective of current experiment was to study the potential influence of hydrolysable tannin supplementation on slaughter performance, meat quality, intestinal digestive enzyme activity, antioxidant ability and barrier function in fattening lambs. In total, 36 male Hu sheep lambs with similar body weight (15.83 ± 0.48 kg) and days in age (55 ± 2 d) were randomly assigned to one of three groups of 12 animals each: control without tannin (CON) and tannin supplementation groups (TA1, 3 g/d per lamb; TA2, 6 g/d per lamb). All the lambs were reared in individual hutches, and the experiment lasted for 60 d. On d 61, 8 lambs from each group were randomly selected to slaughter. Results showed that the serum diamine oxidase and lipopolysaccharide contents of TA2 group were higher (p < 0.05) than those of CON group. Compared with CON group, the carcass weight and intramuscular fat content of lambs in TA1 group were increased (p < 0.05) and the meat shear force was decreased (p < 0.05). The trypsin activity in the jejunum and ileum of TA1 group was higher (p < 0.05) than that of CON and TA2 groups. Also, tannin supplementation significantly increased (p < 0.05) the level of jejunal and ileal total antioxidant capacity and reduced (p < 0.05) the jejunal malondialdehyde concentration in lambs. The jejunum and ileum of TA1 lambs showed reduced (p < 0.05) tumor necrosis factor-alpha and increased (p < 0.05) interleukin-10 mRNA levels compared with CON lambs. In the jejunum, the secretory immunoglobulin A content of TA1 group was higher (p < 0.05) than that of CON and TA2 groups. Lambs supplemented with tannin at the level of 3 g/d increased (p < 0.05) the gene expressions of claudin-1, claudin-4 and zonula occludens-1 in the jejunum when compared to those of CON and TA2 groups. In summary, tannin supplementation at the level of 3 g/d per animal can improve the production performance and intestinal function of fattening lambs fed a high-concentrate diet.

Application of resistance exercise training combined with CT image evaluation in postoperative functional rehabilitation and fracture risk prediction of elderly femurs

ObjectiveTo evaluate the overall functional recovery of femoral patients, improve recovery ability, and prevent fractures in the elderly. MethodsA group of elderly femoral postoperative participants were selected and randomly divided into resistance exercise training and routine rehabilitation training. Simultaneously, a control group (without a history of fractures) and a fracture group (with a history of fractures) were designed to predict fracture risk. Finally, computerized tomography was used to evaluate the functional rehabilitation status. ResultsThe resistance exercise training group showed significantly better performance in functional rehabilitation and fracture risk prediction than the control group, and the decrease in Barthel index at 12 weeks after surgery in this group was 6.25 (P > 0.001). The age, gender, and volumetric bone density between the control group and the fracture group showed P > 0.001, and the differences were statistically significant. The average age of the control group was significantly higher than that of the fracture group, and the proportion of males in the fracture group was significantly higher than that of the control group. The intramuscular fat content of the iliopsoas muscle in the fracture group was significantly lower than that in the control group, P = 0.004. This indicated that lower intramuscular fat content of the iliopsoas muscle was associated with higher fracture risk, as participants with lower intramuscular fat content of the iliopsoas muscle had less bone protection, resulting in an increased risk of fracture. The difference in body mass index between the two groups was not statistically significant, P = 0.737, indicating that the impact of this parameter on fracture risk was not significant in this study. ConclusionResistance exercise training combined with CT image evaluation is an effective rehabilitation strategy with high clinical application value. This study provides reliable empirical evidence for the application of resistance exercise training and the combination of CT image evaluation, and provides guidance for the optimization of clinical rehabilitation strategies.

Effects of Acorns on Meat Quality and Lipid Metabolism-Related Gene Expression in Muscle Tissues of Yuxi Black Pigs.

The aim of this study was to investigate the effects of acorn diets on the composition of fatty acid (FA) and the intramuscular fat (IMF) content in Yuxi black pigs. Ninety Yuxi black pigs with similar body weight (99.60 ± 2.32 kg) were randomly divided into five groups. The control group was fed a basal diet, and the AD20, AD30, AD40, and AD50 groups were fed experimental diets which contained 20%, 30%, 40%, and 50% acorns, respectively. The feeding experiment lasted for 120 days. The results showed that compared with the control group, the content of SFA in longissimus dorsi and biceps femoris tissues in the AD30 group decreased by 8.57% and 20.10%, and the content of MUFA increased by 5.40% and 15.83%, respectively, while the PUFA content of biceps femoris increased by 5.40% (p < 0.05). Meanwhile, the IMF content of the AD30 group was significantly higher than that of the control group in the longissimus dorsi and biceps femoris. In addition, the mRNA expression levels of the ATGL, PPARγ, and FABP4 genes in longissimus dorsi (p < 0.05) were up-regulated, and HSL were down-regulated (p < 0.05) in the AD30 group. In the biceps femoris of the AD30 group, it was observed that the expression levels of the ACC and FAS genes were up-regulated (p < 0.05), while HSL and ATGL genes were down-regulated (p < 0.05). These results demonstrated that the addition of appropriate amounts of acorn to the diet (a 30% acorn diet) could improve the nutritional value of pork.

LncBNIP3 Inhibits Bovine Intramuscular Preadipocyte Differentiation via the PI3K-Akt and PPAR Signaling Pathways.

Intramuscular fat (IMF) content is an economic trait in beef cattle that improves the meat quality. Studies have highlighted the correlation between long noncoding RNAs (lncRNAs) and IMF development. In this study, lncBNIP3 knockdown promoted bovine intramuscular preadipocyte differentiation. RNA-seq analysis of intramuscular preadipocytes with lncBNIP3 knockdown identified 230 differentially expressed genes. The PI3K-Akt and PPAR signaling pathways were enriched. lncBNIP3 interference promoted mRNA and protein expression of key genes in PI3K-Akt signaling pathway. LncBNIP3 interference reversed the effects of an AKT-inhibitor MK-2206 on Akt protein expression and lipid droplet accumulation, promoted mRNA and protein expression of essential genes in the PPAR signaling pathway, and ameliorated the inhibitory effects of a PPARg antagonist GW9662 on lipid accumulation. Therefore, lncBNIP3 inhibition of bovine intramuscular preadipocyte differentiation is likely mediated via the PI3K-Akt and PPAR signaling pathways. This study identified a valuable lncRNA with functional roles in IMF accumulation and revealed new strategies to improve beef quality.

Productive, Physiological, and Environmental Implications of Reducing Crude Protein Content in Swine Diets: A Review.

Pig production is one of the most important providers of high-quality proteins and amino acids (AAs) to human nutrition. In this sector, feeding has an important economic and environmental impact. A strategy to reduce production costs and negative sustainability effects is reducing dietary crude protein (CP) contents with or without AA supplementation. This review addresses the different aspects related to this strategy, particularly the effects on growth performance and pork traits in piglets and growing and finishing pigs, as well as the physiological molecular mechanisms' underlying effects. Insight is also provided into the effects of dietary CP reduction on the productive performances of alternative pig production systems and breeding boars and sows. Finally, an overview is conducted on the effects of dietary CP reduction on ammonia, odor, and greenhouse gas emissions arising from pig production systems. Overall, CP reduction may lead to production losses, albeit they can be, to some extent, hindered by adequate AA supplementation. Losses are particularly relevant during the post-weaning phase, whereas in finishing pigs, it may bring additional benefits, such as high intramuscular fat contents in some markets or improved gut barrier function with benefits to the animals' health and welfare, as well as decreased ammonia emissions to the environment.

Overexpression of ALDOC Promotes Porcine Intramuscular and Intermuscular Fat Deposition by Activating the AKT-mTORC1 Signaling Pathway.

Skeletal muscle fat accumulation, a common complication of obesity, has garnered increasing attention. For livestock animals, intramuscular fat content is a key determinant of meat quality and directly influences consumer preferences for different meat products. However, genes effectively regulating intramuscular and intermuscular fat (IIMF) deposition remain largely unexplored. To address this gap, we employed transcriptome sequencing of muscle from pigs with high and low IIMF contents, uncovering Aldolase C (ALDOC) as a novel key gene controlling IIMF. ALDOC overexpression significantly enhanced the IIMF content both in vivo and in vitro. Mechanistic investigations revealed that ALDOC activates the AKT-mTORC1 axis to promote lipid accumulation in myotubes and intramuscular adipocytes. Notably, the mTORC1 inhibitor rapamycin abrogated ALDOC's proadipogenic effect. Our findings establish ALDOC as a novel key gene regulating IIMF deposition and identify the ALDOC-AKT-mTORC1 signaling pathway as a promising therapeutic target for treating skeletal muscle fat infiltration and improving pork quality.

Integrated analysis of muscle lncRNA and mRNA of Chinese indigenous breed Ningxiang pig in four developmental stages.

Meat and its derivatives serve as crucial sources of protein, vitamins, minerals, and other essential nutrients for humans. Pork stands as China's primary animal-derived food product consumed widely across diverse dietary structures; evaluating intramuscular fat content becomes pivotal in assessing its quality standards. Nonetheless, the intricate molecular mechanisms governing intramuscular fat deposition remain elusive. Our study utilized sequencing technology to scrutinize longitudinal development stages within Ningxiang pig's longest dorsal muscles aiming to unravel these underlying mechanisms. In three distinct comparisons (30d vs. 90d, 90d vs. 150d and 150d vs. 210d) there were 578, 1,000 and 3,238 differentially expressed mRNA, along with 16, 158 and 85 lncRNAs were identified. STEM analysis unveiled six enriched model profiles for lncRNAs while seven such profiles emerged for mRNAs; notably, multiple shared model profiles existed between both RNA types. Enriched analysis highlighted numerous genes from mRNA profile8 and lncRNA profile7 significantly associated with pathways linked to fat deposition. Weight Gene Co-Expression Network Analysis (WGCNA) revealed that differential expression modules (DMEs) & differential expression lncRNAs primarily clustered within cyan, dark slate blue and pale turquoise modules. Furthermore, target genes PKD2 (MSTRG21592.MTRSG8859 and MTRSG18175), COL5A1 (MTRSG9969 and MTRSG180) and SOX13 (MTRSG21592 and MTRSG9088) as core components all intricately tied into processes related to fat deposition. This study lays the groundwork for deeper exploration into the molecular mechanisms underlying LDM fat deposition traits, and it also presents candidate genes for future molecular marker-assisted breeding.

Two-Stage Multimodal Method for Predicting Intramuscular Fat in Pigs

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.