Meat Quality Development Research Articles

Role of Heat-Shock Proteins in the Determination of Postmortem Metabolism and Meat Quality Development of DFD Meat.

This research explored the potential role of various heat-shock proteins (HSPs) in the determination of postmortem metabolism and the development of meat quality of normal, atypical DFD, and typical DFD beef. Beef longissimus thoracis muscle samples were classified into normal, atypical DFD, and typical DFD beef. The HSP27, HSP70, and HSP90 levels, meat quality parameters, and glycolytic metabolites were tested. The results showed that color coordinates (L*, a*, and b*), glycogen, and lactate contents were lower, whereas water-holding capacity was higher in the typical DFD beef than in the normal and atypical DFD beef (p < 0.05). The expression of HSP27 on day 1 was higher in atypical DFD beef. However, expressions of HSP70 on days 1 and 3 were higher in typical DFD, while the expression of HSP90 on day 1 was higher in atypical and typical DFD compared to the normal beef (p < 0.05). Interestingly, the expression of HSP27 was positively correlated with shear force readings. HSP70 and HSP90 presented a direct correlation with pH and water-holding capacity and an indirect correlation with a* and b*, glycogen and lactate contents (p < 0.05). The study concluded that the heat-shock proteins could influence the formation of DFD beef possibly by regulating the development of postmortem metabolism and meat quality traits.

Effects of chronic heat stress on Ca2+ homeostasis, apoptosis, and protein carbonylation profiles in the breast muscle of broilers

Heat stress (HS) largely impairs the quality of broiler breast meat through protein oxidative modification. This study aimed to investigate the carbonylation pattern of Ca2+ channels and apoptotic proteins in the breast muscle of heat-stressed broilers. A total of 144 twenty-eight-day-old male Arbor Acres broilers were randomly divided into three treatment groups. The normal control (NC) group was kept at 22°C and provided with unlimited feed. The HS group was exposed to 32°C and provided with unlimited feed. The pair-fed (PF) group was kept at 22°C and given an amount of feed equivalent to that consumed by the HS group on the previous day. Results showed that broilers under HS conditions had a higher respiratory rate than those in NC and PF groups (P < 0.05). HS disrupted the morphology and structure of breast muscle fibers by decreasing the average diameters and average density of myofibers compared to the NC group (P < 0.05). HS increased the mean fluorescence intensity of the positive carbonyl signal in breast muscle compared with the NC group (P < 0.05). Besides, the pectoral Ca2+ concentration in the sarcoplasmic reticulum, cytoplasm, and mitochondria was elevated by HS when compared with the NC group (P < 0.05). In comparison to the NC and PF groups, HS increased the apoptosis rate and caspase-3 activity in the breast muscle (P < 0.05). Furthermore, HS elevated the relative protein expressions of plasma membrane Ca2+-ATPase, Na+/Ca2+ exchanger 1, and sarco/endoplasmic reticulum calcium transport ATPase 1 compared to the NC group (P < 0.05). Higher relative protein expression of μ-calpain and lower relative protein expression of cytosolic cytochrome complex were found in the HS group than the NC group (P < 0.05). HS decreased the carbonylation levels of transient receptor potential canonical 1 and inositol 1,4,5-trisphosphate receptor compared to the NC group (P < 0.05). Additionally, the carbonylation levels of cleaved caspase-3 and precursor caspase-9 were increased and decreased, respectively, by HS treatment compared to the NC group (P < 0.05). In conclusion, HS damages the myofiber based on Ca2+ dyshomeostasis and apoptosis, which are potentially associated with protein carbonylation. These results shed new light on the possible mechanism behind the development of poor meat quality in broilers due to HS.

Effect of manganese amino acid complexes on growth performance, meat quality, breast muscle and bone development in broilers

ABSTRACT 1. This study was conducted to investigate the effects of dietary supplementation of manganese (Mn) amino acid complexes on growth performance, Mn deposition, meat quality, breast muscle and bone development of broilers. 2. A total of 504, one-day-old male Arbor Acres broilers were randomly divided into seven treatments; control diet (CON; basal diet, no extra Mn addition), manganese diet (MnN as Numine®-Mn; CON + 40, 80, 120 or 160 mg Mn/kg), manganese-S group (MnS; CON + 120 mg Mn/kg as MnSO4·H2O), manganese-A diet (MnA as Mn from hydrolysed feather meal; CON + 40 mg Mn/kg as MnA). 3. There were no significant differences for average daily gain (ADG) or feed intake (ADFI) among diets during the feed phases (p > 0.05). The FCR in the starter and over the whole period were quadratically affected by dietary MnN dosage and gave the lowest FCR at 80 mg/kg (p < 0.05). The Mn content of thigh muscle, jejunum, heart, pancreas, liver and tibia increased linearly with MnN addition (p < 0.05). 4. For meat quality, MnN significantly increased colour (a*), pH45 min and pH24 h, reduced shear force, drip loss and pressure loss of breast muscle (p < 0.05). 5. Moreover, MnN significantly upregulated MYOD expression at d 21 and SOD expression at d 42, decreased MuRF1 and Atrogin-1 mRNA level at d 42 in breast muscle. Transcriptome analysis revealed that the regulating effect of MnN on muscle development significantly enriched signalling pathways such as adhesion, ECM-receptor, MAPK, mTOR and AMPK. Furthermore, dietary MnN significantly affected tibia length and growth plate development (p < 0.05) and promoted growth plate chondrocytes by increasing SOX-9, Runx-2, Mef2c, TGF-β, Ihh, Bcl-2 and Beclin1 and decreasing Bax and Caspase-3 (p < 0.05) expression which affect longitudinal tibial development. 6. In conclusion, Mn amino acid complexes could improve growth performance, tissue Mn deposition, breast muscle development, meat quality and bone development.

Enhancing Muscovy Duck Meat Quality and Growth Development Through Oregano Extract Supplementation: A Study in Agricultural Innovation

This study investigated the effects of oregano extract (OE) supplementation on the growth and meat quality of Muscovy ducks, aiming to optimize meat quality and explore sustainable dietary interventions in poultry production. Twenty-five male Muscovy ducks were meticulously allocated to five treatment groups, each comprising five replications, employing a Completely Randomized Design (CRD). Ducks were exposed to varying levels of oregano extract supplementation with five dietary treatments: T0 (control), T1 (25% OE), T2 (50% OE), T3 ( 75% OE), and T4 (100% OE). Throughout the 4-week trial period, individual ducks were accommodated in designated pens to facilitate precise monitoring. The investigation examined several growth parameters, including feed intake (FI, the amount of feed consumed by each duck), feed cost (FC, the expense associated with feeding each duck), weight gain (WG, the increase in body weight of each duck over the specified time period), and feed conversion ratio (FCR, the ratio of feed consumed to weight gained), assessed at weekly intervals. Results showed that OE supplementation did not significantly affect feed intake or weight gain, except for weeks 1 and 2 where T3, supplemented with 75% OE, exhibited the highest weight gain. However, OE supplementation significantly improved FCR, with T3 showing the lowest FCR, indicating enhanced nutrient utilization. Additionally, T3 displayed the highest fasted live weight, dressed weight, and dressing percentage, suggesting improved meat production and quality. Sensory analysis revealed that T3 consistently exhibited favorable meat quality attributes. Overall, T3 demonstrated the highest general acceptability among consumers, based on criteria such as taste, texture, and overall satisfaction. The study highlights the potential of OE supplementation to optimize feed efficiency and enhance meat quality in Muscovy ducks.

Polystyrene microplastics exposure reduces meat quality and disturbs skeletal muscle angiogenesis via thrombospondin 1

Microplastics (MPs) pose a significant threat to livestock health. Yet, the roles of polystyrene MPs (PS-MPs) on meat quality and skeletal muscle development in pigs have not been fully determined. To investigate the effect of PS-MPs on skeletal muscle, piglets were given diets supplementation with 0 mg/kg (CON group), 75 mg/kg (75 mg/kg PS-MPs group), and 150 mg/kg PS-MPs (150 mg/kg PS-MPs group), respectively. The results indicated that the average daily gain (ADG) of piglets in the 150 mg/kg PS-MPs group was significantly lower than that in the CON group. No significant differences were observed in the final body weight and ADG between the CON group and the 75 mg/kg PS-MPs group. Piglets in the 150 mg/kg PS-MPs group exhibited decreased meat redness index and type I muscle fiber density. Metabolomic analysis revealed that the contents of meat flavor compounds carnosine, beta-alanine, palmitic acid, and niacinamide in muscle were lower in the 150 mg/kg PS-MPs group than in the CON group. Additionally, piglets subjected to 150 mg/kg PS-MPs exhibited impaired muscle angiogenesis. Further analysis indicated that PS-MPs exposure up-regulated thrombospondin 1 (THBS1) expression by inhibiting THBS1 mRNA and protein degradation, thereby disrupting skeletal muscle angiogenesis. These findings indicate that PS-MPs exposure adversely affects meat quality and hinders skeletal muscle angiogenesis in pigs, providing deeper insights into the detrimental effects of PS-MPs on meat quality and skeletal muscle development.

Myogenesis of Porcine Muscle Satellite Cells by Extracellular Matrix From Fibrotic Adipose Tissue-Derived Mesenchymal Stem Cells

Cultivated meat relies on the production of muscle tissue using cell culture techniques. Myogenesis is a cellular differentiation process in which muscle satellite cells (SC) transform into myoblasts, or myotubes. The extracellular matrix (ECM) plays a pivotal role in meat quality, myogenesis, SC proliferation, and muscle tissue development to replicate meat texture. Because fibrotic differentiation and ECM are involved in the myogenic process, we aimed to induce myogenesis in SC using fibrotic differentiation of adipose tissue-derived mesenchymal stem cells (ADSC). ADSC, fibroblasts (FC), and SC were isolated from the back fat, ear margin tissues, and femur muscle tissues, respectively, of a 1-year-old Berkshire piglet. ADSC were treated with connective tissue growth factor (CTGF; 0, 12.5, 25, or 50 ng/mL) for 72 h to induce fibrotic differentiation. Conditioned media from differentiated ADSC and FC were prepared and labeled CA-CM and F-CM, respectively. SC were exposed to CA-CM or F-CM to assess their effects on myogenesis. The results demonstrated &amp;alpha;-smooth muscle actin and collagen I as the optimal markers for assessing fibrotic differentiation in ADSC. CTGF significantly elevated both mRNA and protein expression of &amp;alpha;-smooth muscle actin and collagen I (P &amp;lt; 0.05), suggesting that CTGF acts as an inducer of fibrotic differentiation in ADSC. Moreover, CTGF elevated the expression of ECM components (laminin, fibronectin, and collagen I) in ADSC (P &amp;lt; 0.05). mRNA expression of myogenesis-related genes (MyoG, MyoD, Myf5, and Myf6) increased in SC exposed to both CA-CM and F-CM (P &amp;lt; 0.05). Our data revealed that fibrotic differentiation of ADSC increased ECM production, and ECM-containing conditioned medium induced myogenesis in SC. These findings indicate that ECM-containing conditioned medium is a good option for enhancing myogenesis in SC, with potential implications for cultivated meat production.

Postmortem mitochondria function in longissimus lumborum of Angus and Brahman steers

Mitochondria function and integrity may impact postmortem metabolism and meat quality development. Adaptations in heat tolerant Brahman may persist to limit cellular stress postmortem. Our objective was to evaluate glycolysis, pH decline, and mitochondria function in longissimus lumborum (LL) from Angus and Brahman steers (N = 28) early postmortem (1 to 6 h) and after rigor (24 h). We evaluated metabolites of anaerobic glycolysis, ATP, pH, and temperature, and determined mitochondria oxygen consumption rate (OCR) in permeabilized fibers. The main effects of breed (b) and time (t) and the interaction were tested. Brahman LL contained greater ATP during the first 6 h postmortem; Brahman also tended to exhibit a slower pH decline (b × t, P = 0.07) and more rapid temperature decline (b × t, P < 0.001), but metabolites of anaerobic glycolysis were not different. Mitochondria in Brahman and Angus LL were well-coupled and respired at 1 h postmortem. However, outer membrane integrity became increasingly compromised postmortem (t, P < 0.001). Brahman tended to exhibit greater electron transport system capacity (b, P < 0.1) and had greater capacity for oxidative phosphorylation (complex I and II substrates) at 6 h compared with Angus (P < 0.001). In totality, greater ATP, slower pH decline, and enhanced mitochondria capacity indicate that Brahman possess mitochondrial properties or cellular adaptations that help protect the cell during energy stress postmortem. Slower pH and more rapid temperature decline in LL from Brahman may also help preserve mitochondria function postmortem.

Acetylation and Phosphorylation Regulate the Role of Pyruvate Kinase as a Glycolytic Enzyme or a Protein Kinase in Lamb.

Protein post-translational modifications (PTMs) play an essential role in meat quality development. However, the effect of specific PTM sites on meat proteins has not been investigated yet. The characteristics of pyruvate kinase M (PKM) were found to exhibit a close correlation with final meat quality, and thus, serine 99 (S99) and lysine 137 (K137) in PKM were mutated to study their effect on PKM function. The structural and functional properties of five lamb PKM variants, including wild-type PKM (wtPKM), PKM_S99D (S99 phosphorylation), PKM_S99A (PKM S99 dephosphorylation), PKM_K137Q (PKM K137 acetylation), and PKM_K137R (PKM K137 deacetylation), were evaluated. The results showed that the secondary structure, tertiary structure, and polymer formation were affected among different PKM variants. In addition, the glycolytic activity of PKM_K137Q was decreased because of its weakened binding with phosphoenolpyruvate. In the PKM_K137R variant, the actin phosphorylation level exhibited a decrease, suggesting a low kinase activity of PKM_K137R. The results of molecular simulation showed a 42% reduction in the interface area between PKM_K137R and actin, in contrast to wtPKM and actin. These findings are significant for revealing the mechanism of how PTMs regulate PKM function and provide a theoretical foundation for the development of precise meat quality preservation technology.

Integrated metabolome, proteome, and transcriptome analysis explored the molecular mechanism of phosphoglycerate kinase 1 and pyruvate kinase M2 characterizing the postmortem meat quality

AbstractPhosphoglycerate kinase 1 (PGK1) and pyruvate kinase M2 (PKM2) have been identified as the postmortem meat quality biomarkers. However, the precise molecular mechanism through which they affect and regulate the development of meat quality remains unclear. In this work, the high‐ and low‐activity groups (n = 10) were selected from 60 lamb muscles at 24 h postmortem based on the activity levels of PGK1 and PKM2. The metabolomic, proteomic, and transcriptomic analyses combined with deeply integrated multi‐omics analysis were used to elucidate the mechanisms by which PGK1 and PKM2 characterize meat quality. The results indicated that glycolysis played a crucial role in regulating PGK1 and PKM2 activity at the metabolome, proteome, and transcriptome levels. In glycolysis pathway, we identified several key components closely related to PGK1 and PKM2 activity, including differential metabolites (adenosine triphosphate, adenosine diphosphate, glucose‐6‐phosphate, nicotinamide adenine dinucleotide phosphate, fructose‐6‐phosphate, dihydroxyacetone phosphate, 3‐phosphoglycerate, NAD+ nicotinamide adenine dinucleotide, lactate, and pyruvate), different abundance proteins (lactate dehydrogenase B and fructose bisphosphate aldolase B), and differentially expressed genes (hexokinase and fructose‐1,6‐bisphosphatase 1). It was concluded that PGK1 and PKM2 may affect the formation of meat quality by regulating these critical substrates. Additionally, PGK1 and PKM2 could also affect the tricarboxylic acid cycle, oxidative phosphorylation, and muscle contraction in postmortem and then influence meat quality. This integrative omics study offers valuable insight into unraveling the molecular mechanisms underlying postmortem meat quality development.

Determining muscle plasticity and meat quality development of low-input extended fed market-ready steers.

In March 2020, the World Health Organization declared COVID-19 a pandemic, which ultimately led to many meat processors temporarily shutting down or reducing processing capacity. This backlog in processing capacity forced many feedlots to retain cattle for longer periods of time and assume the risk of major market fluctuations. The aim of this study was to understand how a dietary insult affects meat quality and muscle metabolism in market-ready steers (590kg). Sixteen market-ready (590kg) commercial Angus crossbred steers were subjected to a maintenance diet of either forage or grain for 60 d. Longissimus lumborum (LL) muscle samples were collected immediately postmortem and processed for characteristics reflecting the underlying muscle fiber type and energy state of the tissue. Despite cattle being subjected to a 60-d feeding period, there were no detectable differences (P > 0.05) in carcass characteristics, color of lean, or ultimate pH (pHu). Moreover, our data show that muscle plasticity is rather resilient, as reflected by lack of significance (P > 0.05) in oxidative and glycolytic enzymes, myosin heavy chain isoforms (MyHC), myoglobin, and mitochondrial DNA (mtDNA) contents. These data show that market-ready steers are capable of withstanding a low-input feeding strategy up to 60 d without dramatically impacting underlying muscle characteristics and meat quality development.

Modification-Specific Proteomic Analysis Reveals Cysteine S-Nitrosylation Mediated the Effect of Preslaughter Transport Stress on Pork Quality Development.

This study aimed to explore the effects of preslaughter transport stress on protein S-nitrosylation levels and S-nitrosylated proteome in post-mortem pork longissimus thoracis (LT) muscle. Pigs (N= 16) were randomly divided into 3 h transport (high-stress group, HS) and 3 h transport followed by 3 h resting treatments (low-stress control group, LS). Results demonstrated that high transport stress levels induced nitric oxide (NO) overproduction by promoting NO synthase (NOS) activity and neuronal NOS (nNOS) expression, which thereby notably increased protein S-nitrosylation levels in post-mortem muscle (p < 0.05). Proteomic analysis indicated that 133 S-nitrosylation-modified cysteines belonging to 85 proteins were significantly differential, of which 101 cysteines of 63 proteins were higher in the HS group (p < 0.05). Differential proteins including cytoskeletal and calcium-handling proteins, glycolytic enzymes, and oxidoreductase were mainly involved in the regulation of muscle contraction and energy metabolism that might together mediate meat quality development. Overall, this study provided direct evidence for changes in S-nitrosylation levels and proteome in post-mortem muscle in response to preslaughter transport stress and revealed the potential impact of S-nitrosylated proteins on meat quality.

87 Mitochondria: Life, Death, and the In-Between

Abstract Skeletal muscles exhibit considerable variation in their metabolic and contractile properties, which allows them to accomplish diverse functions in the living animal. Mitochondria content and function are key features driving oxidative capacity, and hence, the energy producing capacity of muscle fibers. In turn, these intrinsic muscle properties also influence postmortem muscle metabolism and the events that occur as living muscle becomes meat. This period is critical to the development of meat quality attributes. Yet, there is much that remains poorly understood regarding the conversion of muscle to meat. Considering that oxygen supply is removed at harvest, early efforts to understand postmortem metabolism primarily focused on glycolytic capacity. More recently, efforts have been redirected to mitochondria; not only are they critical for energy production, but mitochondria also influence calcium dynamics, apoptosis signaling, and reactive oxygen species production. These functions have been implicated in the development of meat quality attributes, including color variation, protein degradation, and tenderness. Defining the mitochondrial contributions to postmortem metabolism and meat quality is complex due to the heterogeneous nature of muscle fibers and the changes in cellular conditions (e.g., temperature, pH) that occur postmortem. Nonetheless, evidence supports that mitochondria retain at least some capacity for energy production early postmortem, indicating they are structurally intact and functional. Both inherent muscle characteristics as well as factors related to slaughter and processing appear to impact the subsequent decline in functional and structural integrity of mitochondria. Unraveling the structural and functional changes that occur in mitochondria postmortem will advance our understanding of early postmortem metabolism and meat quality development.

Proteomic Profiling of Thigh Meat at Different Ages of Chicken for Meat Quality and Development.

Chicken age contributes to the meat characteristics; however, knowledge regarding the pathways and proteins associated with meat quality and muscle development are still scarce, especially in chicken thigh meat. Hence, the objective of this study was to elucidate the intricate relationship between these traits by liquid chromatography mass spectrometry at three different ages. A total of 341 differential expressed proteins (DEPs) were screened out (fold change ≥ 1.50 or ≤0.67 and p < 0.05) among 45 thigh meat samples (15 samples per age) of Beijing-You chicken (BYC), collected at the age of 150, 300, or 450 days (D150, D300, and D450), respectively. Subsequently, based on the protein interaction network and Markov cluster algorithm (MCL) analyses, 91 DEPs were divided into 26 MCL clusters, which were associated with pathways of lipid transporter activity, nutrient reservoir activity, signaling pathways of PPAR and MAPK, focal adhesion, ECM-receptor interaction, the cell cycle, oocyte meiosis, ribosomes, taurine and hypotaurine metabolism, glutathione metabolism, muscle contraction, calcium signaling, nucleic acid binding, and spliceosomes. Overall, our data suggest that the thigh meat of BYC at D450 presents the most desirable nutritional value in the term of free amino acids (FAAs) and intramuscular fat (IMF), and a series of proteins and pathways associated with meat quality and development were identified. These findings also provide comprehensive insight regarding these traits across a wide age spectrum.

Transcriptome analysis reveals FABP5 as a key player in the development of chicken abdominal fat, regulated by miR-122-5p targeting

BackgroundThe development of abdominal fat and meat quality are closely related and can impact economic efficiency. In this study, we conducted transcriptome sequencing of the abdominal fat tissue of Gushi chickens at 6, 14, 22, and 30 weeks, and selected key miRNA-mRNA regulatory networks related to abdominal fat development through correlation analysis.ResultsA total of 1893 differentially expressed genes were identified. Time series analysis indicated that at around 6 weeks, the development of chicken abdominal fat was extensively regulated by the TGF-β signaling pathway, Wnt signaling pathway, and PPAR signaling pathway. However, at 30 weeks of age, the apoptosis signaling pathway was the most significant, and correlation analysis revealed several genes highly correlated with abdominal fat development, including Fatty Acid Binding Protein 5 (FABP5). Based on miRNA transcriptome data, it was discovered that miR-122-5p is a potential target miRNA for FABP5. Cell experiments showed that miR-122-5p can directly target FABP5 to promote the differentiation of preadipocytes.ConclusionThe present study confirms that the key gene FABP5 and its target gene miR-122-5p are critical regulatory factors in the development of chicken abdominal fat. These results provide new insights into the molecular regulatory mechanisms associated with the development of abdomen-al fat in chickens.

Free-Choice Feeding of Whole Grains Improves Meat Quality and Intestinal Development of Pigeon Squabs Compared with Complete Pelleted Feed.

Effects of different feeding strategies on meat quality and intestinal development in pigeon squabs were investigated. 120 pairs of pigeons with two squabs each were assigned to five groups (four free-choice feeding systems and one complete feeding system): T1 (corn, pea, wheat, and pelleted feed), T2 (corn, wheat, and pelleted feed), T3 (corn, pea, and pelleted feed), T4 (corn and pelleted feed), and T5 (complete pelleted feed). Compared with T5, the diet in T4 made the breast meat redder and more yellow (p < 0.05). T2 and T4 resulted in an enhanced total superoxide dismutase activity of meat. Breast muscle in T1 and T2 was determined to have higher contents of nonessential amino acids, glycine, alanine, and glutamic acid (p < 0.05). The contents of the essential amino acids, lysine, threonine, valine, histidine, and arginine were also higher in T1 (p < 0.05). Villus height, surface area, and alkaline phosphatase activity of the duodenum and jejunum in T2 were the highest among the treatments (p < 0.05). In conclusion, free-choice feeding system can improve the meat quality and intestinal development of pigeon squabs, but which combination method of whole grains to use in the production depends on the feeding purpose.

Review of Postmortem Protein Oxidation in Skeletal Muscle and the Role of the Peroxiredoxin Family of Endogenous Antioxidants

The development of fresh meat quality is dictated by biochemical changes during the perimortem and postmortem period. Lipid and protein oxidation in postmortem skeletal muscle and meat products is detrimental to product quality. The mechanisms that influence lipid and protein oxidation in fresh meat remain unelucidated. Peroxiredoxins are thiol-specific antioxidant proteins that are highly reactive and abundant and may be involved in limiting oxidation early postmortem. This review aims to provide a background on oxidation in skeletal muscle, peroxiredoxins, a summary of proteomic experiments associating peroxiredoxins and meat quality, and the importance of context from proteomic methods and results. Additional controlled experiments considering the cellular conditions of postmortem skeletal muscle are necessary to further understand the contribution of peroxiredoxins to fresh meat quality development.

Identification and Functional Prediction of Circular RNAs Related to Growth Traits and Skeletal Muscle Development in Duroc pigs.

Porcine skeletal muscle is a highly heterogeneous tissue type, and the Longissimus Dorsi muscle (LDM), as the most economical and physiologically metabolized skeletal muscle in pigs, has always been the focus of research and improvement in pig molecular breeding. Circular RNA, as an important new member of regulatory non-coding RNA after microRNA, has become a frontier hot spot in life science research. This study aims to explore candidate circRNAs related to growth, meat quality, and skeletal muscle development among Duroc pigs with different average daily gain (ADG). Eight pigs were selected and divided into two groups: H group (high-ADG) and L group (low-ADG), followed by RNA-Seq analysis to identify circRNAs. The results showed that backfat at 6-7 rib (BF) and Intramuscular fat (IMF) content in the H group was significantly lower than L group, but ribeye area (REA) in the H group was higher than in the L group. In RNA-seq, 296 Differentially expressed (DE) circRNAs (157 upregulated and 139 downregulated) were identified and exons flanking long introns are easier to circularize to produce circRNAs. Most of the DE circRNAs were enriched in Quantitative trait locus (QTL) regions related to meat quality and growth traits. In addition, a gene can produce one or more circRNA transcripts. It was also found that the source genes of DE circRNAs were enriched in MAPK, FoXO, mTOR, PI3K-Akt, and Wnt signaling pathways. The results showed that different ADG, carcass, and meat quality traits among half-sibling Duroc pigs with the same diet may be due to the DE circRNAs related to skeletal muscle growth and development.

Carcass Characteristics and Quality Attributes of Beef from Cattle Supplemented Zinc and Ractopamine Hydrochloride

The objective of this experiment was to identify the impact of supranutritional zinc (SUPZN) and ractopamine hydrochloride (RAC) supplementation of beef steers on postmortem protein degradation and tenderness development of extended (&amp;gt;14 d) aged steaks. It was hypothesized that RAC and SUPZN supplementation would influence meat quality development during extended aging of the longissimus thoracis muscle. Crossbred steers (n=27) were fed in a 2 × 2 factorial: control (CON; analyzed 36 mg Zn/kg dry matter) or supranutritional Zn supplementation (SUPZN; CON diet + 60 mg Zn/kg dry matter [from ZnSO4] + 60 mg Zn/kg dry matter [from Zn–amino acid complex]) dietary treatments for the entire 91-d trial. Before harvest (30 d), steers were blocked by body weight within Zn treatments to RAC treatments of 0 or 300 mg per steer per day. Steers were harvested at a commercial processing facility. Carcass characteristics were collected 2 d postmortem. Warner-Bratzler shear force of the Longissimus thoracis was measured at 7, 14, 28, and 42 d postmortem. Calpain-1 autolysis (2 d postmortem) and desmin degradation (2, 7, 14, 28, and 42 d postmortem) were analyzed. RH resulted in greater (P&amp;lt;0.02) Warner-Bratzler shear force values at 7, 14, and 28 d postmortem, lesser (P&amp;lt;0.01) calpain-1 autolysis (76-kDa band) at 2 d postmortem, and lesser (P&amp;lt;0.02) desmin degradation at 2, 7, 14, and 28 d postmortem. Supplementation of Zn resulted in greater (P&amp;lt;0.01) calpain-1 autolysis (78- &amp;amp; 76-kDa band) at 2 d postmortem and a trend for greater (P=0.08) desmin degradation at 2 d postmortem. Tougher steaks from RH supplemented steers were explained by slowed postmortem proteolysis, and Zn supplementation showed evidence to enhance proteolysis early postmortem (2 d). These results demonstrate that nutritional supplementation can impact the rate of tenderness development and postmortem proteolysis in muscle.

Food Industry Byproducts as Starting Material for Innovative, Green Feed Formulation: A Sustainable Alternative for Poultry Feeding.

Rising global populations and enhanced standards of living in so-called developing countries have led to an increased demand of food, in particular meat, worldwide. While increasing the production of broiler meat could be a potential solution to this problem, broiler meat is plagued by health concerns, such as the development of antimicrobial resistance and lower meat quality. For this reason, the supplementation of poultry feed with vitamins and antioxidant compounds, such as polyphenols, has become an attractive prospect for research in this sector. Such supplements could be obtained by extraction of agricultural byproducts (in particular, grape pomaces and artichoke leaves and bracts), thus contributing to reductions in the total amount of waste biomass produced by the agricultural industry. In this review, the effects of poultry feed supplementation with bioactive extracts from grape pomace (skins and/or seeds), as well as extracts from artichoke leaves and bracts, were explored. Moreover, the various methods that have been employed to obtain extracts from these and other agricultural byproducts were listed and described, with a particular focus on novel, eco-friendly extraction methods (using, for example, innovative and biocompatible solvents like Deep Eutectic Solvents (DESs)) that could reduce the costs and energy consumption of these procedures, with similar or higher yields compared to standard methods.

Dairy cow and calf behavior and productivity when maintained together on a pasture-based system.

We determined the impact of maintaining pasture-based dairy cows and calves together over 100 days on cow milk production, cow and calf behavior, and calf liveweight and carcass quality. Six Holstein-Friesian cows and their male calves were monitored for 106±8.6 days. Cows were temporarily separated twice a day for milking with calves remaining in the paddock. Cow and calf behaviors were recorded via scan sampling at 6 different timepoints, for the first 7 days and twice a week thereafter. Calves were weighed weekly and immediately processed for meat quality and rumen development analysis at 106±8.6 days. Daily cow milk yields were collected from enrollment until 109±8.6 days (3 days post-weaning). The average daily gain of calves was 1.4±0.73 kg/d, with an average carcass dressing percentage of 59%. Calves had the greatest frequency of observed close proximity to cow and suckling in the first two weeks and decreased with experiment duration. During separation for milking, cow vocalizations and attempts to return to their calf decreased over time. Reticulorumen weight was on target for calf age, but as a proportion of total stomach weight was lower than industry averages of calves the same age due to the larger abomasum. Cows produced an average of 12±7.6 kg of milk yield per day over the 3-days before the calves were weaned and increased to mean of 31±8.3 kg/d the 3 days after weaning, indicating a consumption of close to 20 kg per calf per day. The impact of a pasture-based cow-calf rearing system on cow and calf behavior and the potential for high levels of calf liveweight gain when provided ad-libitum milk and feed were determined. Further research is required to determine the practicality of replicating such systems with large herds and impact on reared calves post-weaning.