Search

Background and Aim: A Luoi Yellow cattle is an indigenous cattle breed that is raised in the A Luoi District, Vietnam, characterized by its small body size, high adaptability, and meat quality favored by domestic consumers. Marker-assisted selection is an effective approach for improving breeding genetics and sustainably developing livestock production. Therefore, this study aimed to investigate the genetic diversity and polymorphism of genes associated with meat quality and productivity in the A Luoi Yellow cattle population with the goal of future breeding selection and sustainable development of the A Luoi Yellow beef brand. Materials and Methods: In this study, we genotyped six functional genes, including Leptin (LEP), Calpastatin (CAST), Calpain 1, pleomorphic adenoma gene 1, Sirtuin 1, and Sirtuin 2 (SIRT2), involved in meat quality and growth traits using polymerase chain reaction (PCR) or PCR-restriction fragment length polymorphism. We also investigated mitochondrial DNA (mtDNA) and the Y chromosome-specific gene on the Y chromosome to elucidate the genetic diversity and paternal and maternal origin of the A Luoi Yellow cattle using Sanger sequencing. Results: The results showed that A Luoi yellow cattle have Bos indicus origin from both paternal and maternal lineages. By mtDNA analysis, we identified two new haplotypes of the I1 haplogroup that were not previously detected. The genotyping of the six functional genes indicated that A Luoi Yellow cattle carry favorable alleles that increase meat tenderness and body size, with frequencies of 0.02-0.40. In particular, the presence of desirable homozygous genotypes of the CAST, LEP, and SIRT2 genes will be important for the future selection of animals based on their potential performance in meat quality and productivity. Conclusion: The findings of this study is useful for the future breeding and sustainable development of A Luoi Yellow cattle. [ABSTRACT FROM AUTHOR]

Meat quality holds significant importance for both consumers and meat producers. Various factors influence meat quality, and among them, mitochondria play a crucial role. Recent studies have indicated that mitochondria can sustain their functions and viability for a certain duration in postmortem muscles. Consequently, mitochondria have an impact on oxygen consumption, energy metabolism, and apoptotic processes, which in turn affect myoglobin levels, oxidative stress, meat tenderness, fat oxidation, and protein oxidation. Ultimately, these factors influence the color, tenderness, and flavor of meat. However, there is a dearth of comprehensive summaries addressing the effects of mitochondria on postmortem muscle physiology and meat quality. Therefore, this review aims to describe the characteristics of muscle mitochondria and their potential influence on muscle. Additionally, a suitable method for isolating mitochondria is presented. Lastly, the review emphasizes the regulation of oxygen consumption, energy metabolism, and apoptosis by postmortem muscle mitochondria, and provides an overview of relevant research and recent advancements. The ultimate objective of this review is to elucidate the underlying mechanisms through which mitochondria impact meat quality. [ABSTRACT FROM AUTHOR]

This meta-analysis aims to investigate the effects of residual feed intake (RFI) phenotype on performance, nutrient utilization and meat quality traits in Zebu (Bos indicus) cattle. Twenty-three peer-reviewed publications with 37 treatment means were included in the dataset. Weighted mean difference analysis compared animals categorized into low RFI (more efficient) versus medium or high RFI (less efficient) groups. Data heterogeneity via meta-regression and subgroup analysis, considering variables such as animal age, sex class, experimental duration, RFI group, dietary concentrate, and estimated metabolizable energy intake were also explored. The predominant genetic group of cattle in the dataset was Nellore (89.18%), followed by Brahman (10.81%). More efficient animals (low RFI phenotype) exhibited less dry matter intake (DMI; P < 0.010) than medium or high RFI animals (-0.95 kg vs. -0.42 kg/d). Cattle dietary crude protein and fiber digestibility were consistent across RFI groups (P > 0.05), while dietary ether extract digestibility tended to decrease (P = 0.050) in low RFI animals (-13.20 g/kg DM). Low RFI animals tended to increased (P = 0.065) ribeye area (REA) compared to the high/medium RFI groups, while carcass backfat thickness (BFT) decreased (P = 0.042) compared to high/medium RFI groups. Moreover, there was an increase (P < 0.001) of 0.22 kg in Warner-Bratzler shear force (WBSF) and a reduction (P < 0.001) in the myofibrillar fragmentation index (MFI) in low RFI animals. Meat color parameters (lightness [L*] and yellowness [b*]) and visual marbling scores were consistent (P > 0.05) across RFI groups. In conclusion, Zebu cattle classified as efficient (low RFI) exhibited reduced DMI, which improves their feed efficiency. However, BFT and meat quality parameters such as tenderness (WBSF and MFI) and redness [a*] were compromised by low RFI phenotype, highlighting the challenge of enhancing feed efficiency and meat quality traits in Zebu cattle. [ABSTRACT FROM AUTHOR]

Copyright of Alexandria Journal of Food Science & Technology is the property of Egyptian National Agricultural Library (ENAL) and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

ABSTRACT: This study was conducted to evaluate the effects of walnut green husk extract (WGHe) on the growth performance, meat quality, antioxidative status, gut morphology, and microbiota diversity of broilers. A total of 216 one-day-old broilers were divided into 4 groups, each consisting of 9 replicates (6 birds per replicate) as follows: 1) control group, basal diet; 2) antibiotic group, basal diet supplemented with enduracidin and colistin sulfate; 3) low-dose group, basal diet supplemented with 5.0 g/kg WGHe; and 4) high-dose group, basal diet supplemented with 10.0 g/kg WGHe. The results revealed that the percentage of abdominal fat decreased, and the ratio of the duodenal villus length to crypt depth (V/C), as well as the α-diversity of the ileal microbiota, increased with 10.0 g/kg WGHe supplementation (P < 0.05). The shear force of the breast muscle and plasma malondialdehyde (MDA) concentration decreased, whereas the plasma peroxidase (POD) activity, Trolox equivalent antioxidant capacity (TEAC), and jejunal villus length increased in response to WGHe supplementation (P < 0.05). Compared with the antibiotic diet, the addition of 5.0 g/kg WGHe resulted in a significant increase in the relative abundances of Candidatus Arthromitus, Eubacterium coprostanoligenes, and Ruminococcaceae UCG-014 (P < 0.01). Furthermore, the addition of 10.0 g/kg WGHe increased the relative abundances of Candidatus Arthromitus and Lachnoclostridium, whereas the relative abundance of unidentified Chloroplast decreased (P < 0.05). In conclusion, dietary supplementation with 10.0 g/kg WGHe is advantageous for intestinal health, meat quality, and antioxidant status in broilers, suggesting its potential as a functional additive in poultry production.

The meat industry is one of the most dynamic and competitive sectors of the food industry. As the global population keeps on growing and the demand for protein does the same, the consumers define ever higher standards of quality for the meat producers. One of the key quality criteria is the tenderness and juiciness of meat, which directly affects its taste and texture characteristics. In order to satisfy the expectations of the modern consumers and to ensure the stable quality of the meat product, meat processing enterprises actively introduce the innovative technologies. In recent decades, proteolytic enzymes have been increasingly used to improve the quality characteristics of the meat products, which is a more progressive method in comparison with to mechanical methods of processing due to less impact on other consumer properties. This article overviews the role and importance of enzymes in the meat industry. We will consider various aspects of the application of these enzymes for the meat products, their effect on the level of tenderness, juiciness and other characteristics of meat, as well as prospects for the further development of their using

The article investigated the dependence of the histological structure of m. Longissimus thoracis muscle in immunocastrated pigs vaccinated with the “Improvak” vaccine from the company “Zoetis”, USA, and in non-castrated pigs fattened under the conditions of industrial pork production and slaughtered at different live weights. For the study, two experimental groups of 220 gilts each were formed, derived from Irish Landrace and Irish Yorkshire sows and inseminated with semen from boars of the MakGro synthetic line. At the age of 72 days, with an average live weight of 26 kg, they were brought to a fattening farm where the piglets of the research group were vaccinated on the 112th day of life with the vaccine “Improvak” from the company “Zoetis”, USA, in a quantity of 2 ml. They were re-vaccinated on the 148th day of life with the same vaccine and in the same quantity. The pigs in the control group were not castrated. It was found that in m. Longissimus thoracis muscle of immunocastrated pigs using the “Improvak” vaccine, the diameter of the muscle fibres decreased by 15 micrometres and the fibres absorbed more sarcoplasm, which, against the background of a 14 % increase in the content of parenchymal components, indicates an increase in the juiciness and tenderness of the meat. It has been shown that the muscle fibres of the longissimus thoracis no longer grow as a result of the immunocastration of pigs, but take on useful properties, i.e. become hydrated and fat. It was found that pre-slaughter weight had no significant effect on the histological parameters of the longest back muscle of the pigs studied. [ABSTRACT FROM AUTHOR]

Meat tenderness is an important sensory index when consumers choose meat products, which determines the value of meat products and consumers' buying intentions. Yak meat is rich in nutrition and unique in flavor, which is favored by consumers. However, its meat has the deficiencies of low tenderness and poor taste, which has a negative impact on the value of its meat products and customer satisfaction. To identify the genes affecting the yak meat tenderness, we used RNA-seq to analyze the longissimus dorsi muscle of yaks with different tenderness, screened a total of 1120 differentially expressed genes (DEGs). Meanwhile, 23 pathways were significantly enriched. By further analysis, we identified eight genes related to yak meat tenderness (WNT5A, ARID5B, SERPINE1 KLHL40, RUNX1, MAFF, RFX7 and ARID5A). Notably, SERPINE1 was involved in the significant enrichment pathways of 'complement and coagulation cascade pathway', 'HIF-1 signaling pathway' and 'AGE-RAGE signaling pathway in diabetic complications' which can regulate meat tenderness. This implies that SERPINE1 may play an important regulatory role among them. The DEGs associated with yak meat quality screened in this work will be helpful to identify potential biomarkers related to meat tenderness. [ABSTRACT FROM AUTHOR]

Meat tenderness is considered the most important trait contributing to beef quality, level of consumer satisfaction, willingness to pay premium prices and industry profit. Genomic selection method would be helpful for genetic improvement of traits with low heritability and that are difficult to measure. The identification of core genes can aid genomic selection for complex traits with low heritability that are difficult to measure. We performed statistical analysis of associations between longissimus dorsi muscle tenderness and gene expression in 20 Hanwoo cattle, using Warner–Bratzler shear force and RNAseq data, respectively. We found a total of 166 core genes, from which six (ASAP1, CAPN5, ELN, SUMF2, TTC8 and MGAT4A) were regulated by 16 cis‐expression quantitative trait loci (eQTL) SNPs. Notably, we found that a cis‐eQTL SNP of the ELN gene contained an MFZ‐1 binding site in its putative promoter region. These findings provide useful information for genomic prediction of beef tenderness in Hanwoo cattle. [ABSTRACT FROM AUTHOR]

The use of toxic and less bioavailable inorganic selenium can now be substituted with an alternative organic source obtained from bacterial species to benefit human and animal nutrition. This study investigates the effects of selenium sources on laying hen's meat quality. A total of 144 Mid-Producing Lohman Brown Classic laying hens, aged 23 weeks, were divided into four experimental groups (each with 36 hens) based on the form of Se supplementation (no Se supplementation, 0.3 mg/kg of inorganic Se in the form of sodium selenite, 0.3 mg/kg organic Se from Sel-Plex, Alltech Inc., Nicholasville, KY), and 0.3 mg/kg organic Se from Stenotrophomonas maltophilia (bacterial organic Se). The trial period was seventeen weeks, after which the hens were slaughtered and breast muscles sampled at week 40. The results showed that dietary Se supplementation enhanced (P<0.05) cooking loss, drip loss, and meat tenderness of breast muscles significantly in the enriched bacterial Se group compared to the inorganic and basal diet groups. Se sources also had a significant impact (P<0.05) on the colour (lightness, redness, and yellowness) of the breast meat. Bacterial organic Se supplementation reduced cooking loss and drip loss, and it improved the tenderness and breast meat colour of Lohman brown laying hens. [ABSTRACT FROM AUTHOR]

The objective of this study was to examine the effect of short-term transportation and lairage time on meat quality, myofibrillary structure, calpastatin (CAST), µ-calpain (CAPN1), calpain 3 (CAPN3), and heat shock protein 70 (HSPA1A) expression levels of M. longissimus dorsi of Kıvırcık breed sheep (n=40). Meat quality was evaluated by muscle glycogen amounts, pH, temperature, cooking loss, water holding capacity, shear force, instrumental color, sarcomere length, and organoleptic properties. Cellular changes in the muscle during the aging process were scanned by electron microscopy and CAST, CAPN1, CAPN3, HSPA1A expression levels were measured to reveal the association on meat tenderness. As a result, a positive effect of long lairage time groups was observed in the pH, glycogen, SF values, and organoleptic evaluation. CAST, CAPN1, CAPN3 expression showed no difference, however, HSPA1A showed a significant difference in the aging process. In conclusion, genotypic differences, their effect on gene expression, and protein level on meat quality should be further investigated. [ABSTRACT FROM AUTHOR]

The effectiveness of dry ageing with regard to retaining meat quality is still subject to debate. At 4 d post mortem, samples of boneless strip loins were excised from young Charolais carcasses and then stored for a further 26 d in a cooler, either vacuum-packaged (VP) or dried-aged (DA). Loin samples were also dissected 7 d post mortem as a control treatment (CT). Chemical, instrumental and microbiological data (n = 18) were determined in longissimus dorsi and underwent ANOVA to estimate the differences in the ageing fixed factor split into two orthogonal contrasts: control vs. aged and VP vs. DA. Ageing loss (both surface dehydration and water purge) was greater in DA compared to VP samples, resulting in the lowest moisture content and highest crude protein and fat percentage in DA loins. The ageing method did not affect meat surface colour, except for redness, which had the lowest value in DA samples. Meat tenderness improved a similar amount following both VP and DA ageing treatments. Compared to the control, prolonged ageing raised both the peroxide value and the total microbial count, especially in DA samples, though both remained within the recommended limits. In summation, both ageing methods improved beef meat tenderisation, preserving its shelf life. [ABSTRACT FROM AUTHOR]

Methionine is indispensable for growth and meat formation in pigs. However, it is still unclear that increasing dietary sulphur-containing amino acid (SAA) levels using different methionine sources affects the growth performance and meat quality of barrows and gilts. To investigate this, 144 pigs (half barrows and half gilts) were fed the control (100% SAA, CON), DL-Methionine (125% SAA, DL-Met)-supplemented, or OH-Methionine (125% SAA, OH-Met)-supplemented diets during the 11–110 kg period. The results showed that plasma methionine levels varied among treatments during the experimental phase, with increased plasma methionine levels observed following increased SAA consumption during the 25–45 kg period. In contrast, pigs fed the DL-Met diet had lower plasma methionine levels than those fed the CON diet (95–110 kg). Additionally, gilts fed the DL-Met or OH-Met diets showed decreased drip loss in longissimus lumborum muscle (LM) compared to CON-fed gilts. OH-Met-fed gilts had higher pH45min values than those fed the CON or DL-Met diets, whereas OH-Met-fed barrows had higher L45min values than those fed the CON or DL-Met diets. Moreover, increased consumption of SAA, regardless of the methionine source, tended to decrease the shear force of the LM in pigs. In conclusion, this study indicates that increasing dietary levels of SAA (+25%) appeared to improve the meat quality of gilts by decreasing drip loss and increasing meat tenderness.

Mutton, buffalo and beef meats have a tough texture and sometime is hard to eat. Naturally, enzymatic processing using plant-based compound, including, chayote (Sechium edule), pineapple (Ananas comosus) and biduri (Calotropis gigantea) contains abundance protease that potential to be developed. This research aims to compare the effect chayote, pineapple peel and biduri leaves to tenderize mutton, beef and buff meat at various doses. The sample meats, mutton, beef and buff were obtained from upper leg (round) part. The chayote, pineapple peel powder and biduri leaves was processed into powder and used to smear meats surface with the concentration of 5, 10 and 15 % of natural tenderizers powder from total meat wight (w/w), for 60 min. After treatment the Barford protein analysis using Bio-Rad protein assay was conducted to measure protein concentration, continued with SDS-PAGE analysis using Laemlli method. The structural observation was performed using Scanning Electron Microscope (SEM). The result performs hydrolysis process using pineapple and biduri leaves on mutton and beef produce light protein bands below 26, 34 and between 55 to 43 kDa. The application of natural tenderizer, including pineapple peel, biduri leaf and chayote peel is effectively tenderize the mutton, beef and buff meat. Furthermore, the pineapple peel and biduri leaves powder are the most potential tenderizer for mutton and beef. However, buff is most least tenderized meat among other and it may need an extra dosage or incubation period to get appropriate result. [ABSTRACT FROM AUTHOR]

Genes or genetic markers related to meat quality have been studied for many years. Th e CAST gene is one candidate gene aff ecting meat tenderness in cattle. Th is meta-analysis aimed to examine the association of c.2832A>G polymorphism of the CAST gene and meat tenderness in cattle. According to the determined criteria, 17 studies were included in the meta-analysis, and pooled ratios of allele and genotype frequencies were calculated. In addition, the combined Warner-Braztler Shear Force values were calculated for three studies that reported these values according to genotypes for the meat tenderness feature. Heterogeneity between studies and publication bias were also tested. As a result of the meta-analysis, pooled ratios of AA, AG, and GG genotypes are 0.578, 0.342, and 0.080; pooled ratios of A and G alleles are 0.777 and 0.223. Th e highest pooled ratios were obtained for AA genotype and A allele. Th e combined Warner-Braztler shear force values were calculated as 3.707, 3.893, and 5.137 kilogram-force for AA, AG, and GG genotypes. Th e highest mean shear force value was obtained for the GG genotype. In conclusion, the meta-analysis results examined the relationship between c.2832A>G polymorphism of the CAST gene and meat tenderness were closer to the population parameter. Th is study may improve genetic selection and provide new strategies to increase meat quality in cattle.

Meats consist of edible portions originating from domestic and wild animals. Meat's palatability and sensory accessibility largely depend on its tenderness to consumers. Although many factors influence meat tenderness, the cooking method cannot be neglected. Different chemical, mechanical, and natural means of meat tenderization have been considered healthy and safe for consumers. However, many households, food vendors, and bars in developing countries engage in the unhealthy use of acetaminophen (paracetamol/APAP) in meat tenderization due to the cost reduction it offers in the overall cooking process. Acetaminophen (paracetamol/APAP) is one of the most popular, relatively cheap, and ubiquitous over-the-counter drugs that induce serious toxicity challenges when misused. It is important to note that acetaminophen during cooking is hydrolyses into a toxic compound known as 4-aminophenol, which damages the liver and kidney and results in organ failure. Despite the reports on the increase in the use of acetaminophen for meat tenderizing in many web reports, there have not been any serious scientific publications on this subject. This study adopted classical/traditional methodology to review relevant literature retrieved from Scopus, PubMed, and ScienceDirect using relevant key terms (Acetaminophen, Toxicity, Meat tenderization, APAP, paracetamol, mechanisms) and Boolean operators (AND and OR). This paper provides in-depth information on the hazard and health implications of consuming acetaminophen tenderized meat via genetic and metabolic pathways deductions. Understanding these unsafe practices will promote awareness and mitigation strategies.

The aim of the present study was to evaluate the efficiency of selection for body growth and its association with carcass and meat quality traits in the red-winged tinamou. Two experimental groups were selected based on the selection index: selection group with a higher index (TinamouS) and commercial group with a lower index (TinamouC). Weight at 180 days and slaughter weight were significantly higher (p < 0.05) in the TinamouS group, as were hot carcass weight, skinless breast weight, wing weight, and thigh and drumstick weight. The meat quality traits or sensory attributes did not differ significantly (p > 0.05) between groups. A significant positive correlation (0.59; p < 0.05) was found between shear force and chewability and a significant negative correlation (− 0.59; p < 0.05) between aroma intensity and strange aroma. The present study suggests that the selection index promotes greater body growth and preserves meat quality and sensory traits in red-winged tinamou. [ABSTRACT FROM AUTHOR]

This study was conducted to evaluate the effects of walnut green husk extract (WGHe) on the growth performance, meat quality, antioxidative status, gut morphology, and microbiota diversity of broilers. A total of 216 one-day-old broilers were divided into 4 groups, each consisting of 9 replicates (6 birds per replicate) as follows: 1) control group, basal diet; 2) antibiotic group, basal diet supplemented with enduracidin and colistin sulfate; 3) low-dose group, basal diet supplemented with 5.0 g/kg WGHe; and 4) high-dose group, basal diet supplemented with 10.0 g/kg WGHe. The results revealed that the percentage of abdominal fat decreased, and the ratio of the duodenal villus length to crypt depth (V/C), as well as the α-diversity of the ileal microbiota, increased with 10.0 g/kg WGHe supplementation (P < 0.05). The shear force of the breast muscle and plasma malondialdehyde (MDA) concentration decreased, whereas the plasma peroxidase (POD) activity, Trolox equivalent antioxidant capacity (TEAC), and jejunal villus length increased in response to WGHe supplementation (P < 0.05). Compared with the antibiotic diet, the addition of 5.0 g/kg WGHe resulted in a significant increase in the relative abundances of Candidatus Arthromitus, Eubacterium coprostanoligenes , and Ruminococcaceae UCG-014 (P < 0.01). Furthermore, the addition of 10.0 g/kg WGHe increased the relative abundances of Candidatus Arthromitus and Lachnoclostridium , whereas the relative abundance of unidentified Chloroplast decreased (P < 0.05). In conclusion, dietary supplementation with 10.0 g/kg WGHe is advantageous for intestinal health, meat quality, and antioxidant status in broilers, suggesting its potential as a functional additive in poultry production. [ABSTRACT FROM AUTHOR]

Growing consumer awareness is forcing food producers to supply raw material and products of increasingly high quality and health-promoting properties. Knowledge of the genetic background of quality characteristics is taking on great importance, enabling selection based on molecular markers. The increasing throughput of molecular techniques, in combination with an expanding bioinformatics infrastructure, is leading to continual improvement in understanding of the molecular mechanisms influencing meat quality. This has resulted in the identification of polymorphic nucleotides [single nucleotide polymorphisms (SNPs)] showing a relationship with meat characteristics such as tenderness [polymorphism in the calpain (CAPN) and calpastatin (CAST) genes], marbling [diacylglycerol o-acyltransferase 1 (DGAT1)], colour, pH and water-holding capacity (WHC) [CAST, stearoyl-CoA desaturase (SCD) and others], and fatty acid profile (SCD1). An increasingly wide range of methods is used for analysis, from techniques based on amplification of nucleic acids [polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) and amplification refractory mutation system-PCR (ARMS-PCR)] through Sanger sequencing to high-throughput next-generation sequencing (NGS) techniques. This paper is a review of the literature on polymorphism of genes determining the quality characteristics of meat and molecular methods used to detect them.

Objective An experiment was conducted to evaluate the effects of increasing levels of spineless cactus (0%, 33%, 66%, and 100%) used as a substitute for wheat bran in buffalo diets on quantitative and qualitative traits of the meat and carcass. Methods Twenty Murrah buffaloes at 18 months of age, with a mean initial weight of 292.9±57.3 kg, were randomly allocated to four treatments with five replicates. The animals were slaughtered after 90 days in the feedlot. The effects of spineless cactus as a replacement for wheat bran in the diet of the buffaloes on the carcass and meat traits, slaughter weight, carcass yield and carcass measurements were studied. Results Increased spineless cactus levels led to linear reduction in average daily gain, slaughter weight, hot and cold carcass weight, compactness index and in the amount of muscle in the carcass, and there is no difference between the control treatment and the 33% replacing level for these parameters. The quality of the meat was not influenced by the treatments. Conclusion Spineless cactus can replace wheat bran by up to 33% in sugarcane-based diets for buffaloes, without influencing quantitative and qualitative traits of the meat and carcass.

ABSTRACT: The objective of this research was to investigate the effects of Mahuang and Tuer chickens, 2 representatives of the native chicken breed, and the slaughter age on meat quality and flavor compounds of soft-boiled chickens (SCs) in comparison to a commercial cross boiler. A total of 432 chicks were randomly allocated into the following groups: 817 groups raised for 55 d, and Mahuang and Tuer chickens raised for 60, 65, 70, and 75 days (d). After the completion of rearing period, the chickens were slaughtered, and 5 carcasses per group were randomly selected for SC manufacturing. Meat quality was determined based on product yield, pH, color, meat tenderness, and textural and sensorial attributes. The volatile compounds of chicken breast were identified by gas chromatography-ion mobility spectrometry (GC-IMS). The results showed that the yellow-feathered chicken breed, especially Mahuang chicken, had a higher product yield, and lower shear force and sensorial scores than the cross broiler. The pH, L* and b* values in SC breast meat were not significantly influenced by breed (P > 0.05), while greater a* was observed in SC of yellow-feathered chickens compared to cross broilers. The slaughter age had a significant effect on the pH, color, shear force, and textural properties of SC (P < 0.05). The meat tenderness of SC was significantly decreased as the age of chicken increased from 65 d to 75 d (P < 0.05). The relatively young age of yellow-feathered chickens (60 d and 65 d) was rated to have a higher overall sensory score of SC (P < 0.05). A total of 65 organic volatile compounds were identified in SC, including 18 aldehydes, 16 alcohols, 10 ketones, 9 esters, 2 acids, 3 furans, 5 pyrazines, and 2 sulfur-containing compounds. Three chicken breeds were separately clustered in the plot of principal component analysis, indicating breed-specific flavor characteristics. Collectively, the present study provides valuable information for SC processing in terms of carcass selection of yellow-feathered chicken breeds and slaughter age.

Simple Summary: A bibliometric analysis was carried out to know the evolution of research on genes associated with meat tenderness, of interest for the development of selection programs. Since 1993, studies have been limited to a few researchers in high-income countries due to the costs associated with the techniques. The main findings showed that the scientific production had a discontinuous growth because science experienced a significant change since approximately 2010. Marker-assisted selection was widely used, evaluating mainly CAPN (calpain) and CAST (calpastatin) genes for their contribution to meat tenderness, especially in cattle. However, the effects are small; therefore, genomic selection was implemented by genotyping thousands of single nucleotide polymorphisms (SNPs) for further explanation of genetic variation. The results shown are important for scholars to identify emerging methodologies and gaps in the literature and to know who the prolific authors and institutions in the field for possible collaborations, etc., are. Tenderness is one of the main characteristics of meat because it determines its price and acceptability. This is the first bibliometric study on the trend of research on the role of genes in meat tenderness. A total of 175 original and English-language articles published up to 2021 were retrieved from Scopus. The bibliometric analysis was carried out with VOSviewer (version 1.6.18, Eck and Waltman, Leiden, Netherlands) and complemented with the Analyze search results service from Scopus. Erroneous and duplicate data were eliminated, and incomplete information was added to standardize the results. Scientific production was evaluated by means of quantity, quality and structure indicators. As a first glance, 8.816% of authors have published more than 50% of papers mainly related to genes encoding the calpain (CAPN)-calpastatin (CAST) system and single nucleotide polymorphisms (SNPs). Among other findings, a strong link was found between the contribution of the main countries (led by the United States with) and their institutions (led by the USDA Agricultural Research Service with) to their gross domestic product. Most studies on the topic are published in the Journal of Animal Science, and other journals with high impact according to the number of citations and different metrics. Finally, when evaluating the most cited articles, the occurrence and association of the main keywords, it was confirmed that research is focused on the role of CAPN and CAST genes and of SNPs in beef tenderness. The change in science was emphasized; although marker-assisted selection is still used, genes have an infinitesimal effect on complex traits. Therefore, since about 2010, new research groups adopted genomic selection to evaluate dense panels of SNPs and better explain genetic variation in meat tenderness. [ABSTRACT FROM AUTHOR]

Genes or genetic markers related to meat quality have been studied for many years. The CAST gene is one candidate gene affecting meat tenderness in cattle. This meta-analysis aimed to examine the association of c.2832A>G polymorphism of the CAST gene and meat tenderness in cattle. According to the determined criteria, 17 studies were included in the meta-analysis, and pooled ratios of allele and genotype frequencies were calculated. In addition, the combined Warner-Braztler Shear Force values were calculated for three studies that reported these values according to genotypes for the meat tenderness feature. Heterogeneity between studies and publication bias were also tested. As a result of the meta-analysis, pooled ratios of AA, AG, and GG genotypes are 0.578, 0.342, and 0.080; pooled ratios of A and G alleles are 0.777 and 0.223. The highest pooled ratios were obtained for AA genotype and A allele. The combined Warner-Braztler shear force values were calculated as 3.707, 3.893, and 5.137 kilogram-force for AA, AG, and GG genotypes. The highest mean shear force value was obtained for the GG genotype. In conclusion, the meta-analysis results examined the relationship between c.2832A>G polymorphism of the CAST gene and meat tenderness were closer to the population parameter. This study may improve genetic selection and provide new strategies to increase meat quality in cattle. [ABSTRACT FROM AUTHOR]

The effectiveness of dry ageing with regard to retaining meat quality is still subject to debate. At 4 d post mortem, samples of boneless strip loins were excised from young Charolais carcasses and then stored for a further 26 d in a cooler, either vacuum-packaged (VP) or dried-aged (DA). Loin samples were also dissected 7 d post mortem as a control treatment (CT). Chemical, instrumental and microbiological data (n = 18) were determined in longissimus dorsi and underwent ANOVA to estimate the differences in the ageing fixed factor split into two orthogonal contrasts: control vs. aged and VP vs. DA. Ageing loss (both surface dehydration and water purge) was greater in DA compared to VP samples, resulting in the lowest moisture content and highest crude protein and fat percentage in DA loins. The ageing method did not affect meat surface colour, except for redness, which had the lowest value in DA samples. Meat tenderness improved a similar amount following both VP and DA ageing treatments. Compared to the control, prolonged ageing raised both the peroxide value and the total microbial count, especially in DA samples, though both remained within the recommended limits. In summation, both ageing methods improved beef meat tenderisation, preserving its shelf life.

The study investigated the glycolysis pathway mediated by hypoxia‐inducible factor‐1α (HIF‐1α) and the mechanism of its regulation. The results indicated that HIF‐1α expression initially increased before subsequently decreasing with aging time during postmortem (p <.01). Glucose transporter‐1 (GLUT‐1), lactate dehydrogenase (LDH), and hexokinase (HK) displayed a similar trend with aging time (p <.01) while pyruvate dehydrogenase kinase 1 (PDK‐1) increased gradually within the first 12 hr before decreasing at 24–120 hr. However, after treatment with a HIF‐1α inhibitor, no significant differences were observed in the mitochondrial morphology. Furthermore, lactate content decreased, along with LDH, HK, and F0F1‐ATP activities as well as GLUT‐1 and PDK‐1 expression (p <.01). The shear force for all groups also increased during postmortem aging (p <.01), with that of the controls being significantly higher compared with the treatment groups (p <.01). These findings confirmed that, after slaughter, the hypoxic environment within the muscles provided essential conditions for HIF‐1α expression, which, in turn, activated the glycolysis pathway by mediating changes in the activities of glycolytic enzymes and mitochondrial function. Moreover, in accelerating glycolysis rate, the expression of HIF‐1α further played a negative role in meat tenderization during postmortem aging. This, it was concluded that HIF‐1α expression plays a significant role in postmortem yak meat tenderization by regulating the glycolysis pathway. Pratical applications: While converting muscle into meat through hypoxic glycolysis during postmortem aging is undeniable, the biochemical mechanism of this process mediated remains quite obscure. However, the meat quality difference which impact muscle regulation mechanism during postmortem aging has not been reported. The study investigated the HIF‐1α played a major role in both the glycolytic pathway and as well as meat tenderness during the postmortem aging of yak meat. The glycolysis pathway is mediated by hypoxia‐inducible factor‐1α (HIF‐1α), the mechanism of its regulation, and meat tenderness during the postmortem aging of yak meat. [ABSTRACT FROM AUTHOR]

Tenderness is considered a crucial attribute of postmortem meat quality, directly influencing consumers' preferences and industrial economic benefits. The degradation of myofibrillar proteins by endogenous enzymes within muscle fibers is believed to be the most effective pathway for meat tenderization. After animals are slaughtered and exsanguinated, there is a significant accumulation of reactive oxygen species (ROS), and a dramatic depletion of adenosine triphosphate (ATP) in muscle, leading to inevitable cell death. Caspases are activated in postmortem muscle cells, which disrupt the cell structure and improve meat tenderness through protein hydrolysis. In this review, we systematically summarized the three primary types of cell death studied in postmortem muscle: apoptosis, autophagy and necrosis. Furthermore, we emphasized the molecular mechanisms of apoptosis and its corresponding apoptotic pathways (mitochondrial apoptosis, death receptors, and endoplasmic reticulum stress) that affect meat tenderness during muscle conversion to meat. Additionally, factors affecting apoptosis were comprehensively discussed, such as ROS, heat shock proteins, calcium (Ca2+)/calpains, and Bcl-2 family proteins. Finally, this comprehensive review of existing research reveals that apoptosis is mainly mediated by the mitochondrial pathway. This ultimately leads to myofibrillar proteins degradation through caspase activation, improving meat tenderness. This review summarizes the research progress on postmortem muscle apoptosis and its molecular mechanisms in meat tenderization. We hope this will enhance understanding of postmortem meat tenderness and provide a theoretical basis for meat tenderization techniques development in the future. • This review provides a comprehensive understanding of apoptosis and its role in postmortem meat tenderness. • Apoptosis is mainly mediated by the mitochondrial pathway in postmortem muscle. • Apoptosis ultimately leads to myofibrillar proteins degradation through caspase activation, improving meat tenderness. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate instrumental and eating qualities of meat from Afar and Hararghe Highland Rams subjected to different energy and protein levels in the diet. Fifty yearling rams with a mean IBW of 19.31 ± 1.7 kg (Mean±SD) was randomly distributed into five dietary treatments i.e., minimum energy and protein (mEmP), medium energy and protein (MEMP), medium energy and high protein (MEHP), high energy and medium protein (HEMP), and high Energy and high protein (HEHP) diets in randomized complete block design with 2 × 5 factorial arrangements. The minimum, medium, and high energy diets were: 2.388, 2.866, and 3.344 Mcal/kgDM with the corresponding 10, 16, and 20% crude protein (CP) diets. The diets were formulated in a total mixed ration from wheat bran, maize grain, peanut cake, and pasture hay feed ingredients. There was significant (P<0.01) effects of breed and diets on meat physicochemical parameters (dissected lean, fat, bone, water holding capacity, and chemical compositions), eating qualities (flavor, juiciness and tenderness) and instrumental qualities (Warner-Brazilier shear force and meat color index values [(red (a*); light (L*); yellow (b*)]. Hararghe rams had higher (P<0.01) fat composition, waterholding capacity (WHC), light (L*; 32.4 vs. 29.8) and yellow (b*; 9.4 vs. 8.4) color index values, and tender meat (19.60 vs. 23.38 N/cm2) as compared to Afar rams. MEHP and HEMP diets were appropriate in promoting better meat quality while MEMP was optimum resulting in desirable meat qualities in both sheep breeds. Meat from both breeds and rams fed on all diets was in the acceptable ranges set for meat quality parameters. Major meat quality defects (dark cutting) observed on slaughtering of free grazing animals directly bought from highland areas has been improved by this feeding and management systems. [ABSTRACT FROM AUTHOR]

The study investigated the effect of crossbreeding Charolais bulls with Nguni cows on carcass and lean yield and meat quality characteristics. The intact Charolais bulls (n=10) served as control group against the Charolais x Nguni (n=10). The Nguni dam proved a good option for a dam line because of the hardiness of the breed, its mothering ability, ease of calving, and low maintenance cost. In contrast, the Charolais had excellent growth and carcass characteristics. It was a late maturing breed with better growth performance and higher yields than Charolais x Nguni, which could be classified as a medium maturing beef breed. Over the same duration and conditions of feeding the Charolais calves had better feed conversion and growth rates and produced larger carcasses than Charolais x Nguni calves. Owing to the large difference in carcass size, the Charolais had better meat to bone ratio than the Charolais x Nguni (P <0.001). Both breeds produced meat with a desirable appearance and good eating quality and no differences were recorded in the related traits. It could be concluded that Charolais and Charolais x Nguni weaned calves were well suited to the grain-fed market and would produce meat of acceptable quality. [ABSTRACT FROM AUTHOR]

Diacylglycerol acyltransferase-1 (DGAT1) has been recognised as one of the functional genes during fat deposition and closely related to meat quality. It is well known that yak meat has low intramuscular fat (IMF) and poor tenderness, influencing the purchase decision for consumers. In this study, the variations of DGAT1 gene were detected using polymerase chain reaction single-stranded conformational polymorphism (PCR-SSCP) analysis so as to ascertain the association of DGAT1 variation with yak carcase and meat quality traits. Two variants (A1 and B1) in intron 1 – exon 2 and another three variants (A2 to C2) in intron 15 – exon 17 were identified in the yaks investigated. Three sequence variations (c.192-117 G > A, c.1252-23 C > T and c.1339 C > T) were detected among these variants, with c.192-117 G > A located in intron 1, c.1252-23 C > T located in intron 15 and c.1339 C > T located in exon 17. The mutation c.1339 C > T resulted in an amino acid change (p. Arg 447 Cys). Variants A1 and B2 were associated with a decrease and increase in Warner–Bratzler shear force (WBSF) (p = 0.027 and p

Objective: An experiment was conducted to evaluate the effects of increasing levels of spineless cactus (0%, 33%, 66%, and 100%) used as a substitute for wheat bran in buffalo diets on quantitative and qualitative traits of the meat and carcass. Methods: Twenty Murrah buffaloes at 18 months of age, with a mean initial weight of 292.9±57.3 kg, were randomly allocated to four treatments with five replicates. The animals were slaughtered after 90 days in the feedlot. The effects of spineless cactus as a replacement for wheat bran in the diet of the buffaloes on the carcass and meat traits, slaughter weight, carcass yield and carcass measurements were studied. Results: Increased spineless cactus levels led to linear reduction in average daily gain, slaughter weight, hot and cold carcass weight, compactness index and in the amount of muscle in the carcass, and there is no difference between the control treatment and the 33% replacing level for these parameters. The quality of the meat was not influenced by the treatments. Conclusion: Spineless cactus can replace wheat bran by up to 33% in sugarcane-based diets for buffaloes, without influencing quantitative and qualitative traits of the meat and carcass. [ABSTRACT FROM AUTHOR]

Growing consumer awareness is forcing food producers to supply raw material and products of increasingly high quality and health-promoting properties. Knowledge of the genetic background of quality characteristics is taking on great importance, enabling selection based on molecular markers. The increasing throughput of molecular techniques, in combination with an expanding bioinformatics infrastructure, is leading to continual improvement in understanding of the molecular mechanisms influencing meat quality. This has resulted in the identification of polymorphic nucleotides [single nucleotide polymorphisms (SNPs)] showing a relationship with meat characteristics such as tenderness [polymorphism in the calpain (CAPN) and calpastatin (CAST) genes], marbling [diacylglycerol o-acyltransferase 1 (DGAT1)], colour, pH and water-holding capacity (WHC) [CAST, stearoyl-CoA desaturase (SCD) and others], and fatty acid profile (SCD1). An increasingly wide range of methods is used for analysis, from techniques based on amplification of nucleic acids [polymerase chain reaction-restriction fragment length polymorphism (PCR- -RFLP) and amplification refractory mutation system-PCR (ARMS-PCR)] through Sanger sequencing to high-throughput next-generation sequencing (NGS) techniques. This paper is a review of the literature on polymorphism of genes determining the quality characteristics of meat and molecular methods used to detect them. [ABSTRACT FROM AUTHOR]

The poultry industry has attempted to improve carcass chilling efficiency, meat quality, and product safety. The purpose of this research was to investigate the effects of subzero saline chilling on carcass chilling, breast fillet tenderness, and microbial safety. After evisceration, broiler carcasses were chilled using ice slurry control (0% NaCl/0.5°C) or subzero saline solutions (3% NaCl/−1.8°C and 4% NaCl/−2.41°C). Broiler carcasses in the subzero saline solutions were chilled efficiently and reduced the chilling time by 11% in 3% NaCl/−1.8°C and 37% in 4% NaCl/−2.41°C over the ice slurry chilling. The breast fillets of broiler carcasses in 4% NaCl/−2.41°C were significantly tenderized than those in water control (P

Objective The aim of the present study was to determine the effect of supplementing pasture-finished steers with corn silage on the expression level of the calpain system proteins and beef tenderization. Methods Thirty Braford steers grazing on summer pasture were used for the study. For 120 days fifteen animals were supplemented with corn silage at 1% of body weight per head per day (Suppl) whereas the remaining 15 steers only received pasture (Contr). Carcass and meat traits were evaluated and compared between groups. Gene expression and activities of proteases (calpain 1 and calpain 2) and inhibitor (calpastatin) were measured using real-time polymerase chain reaction and casein zymography. Results Carcass and meat traits were significantly different between feeding systems. Supplemented steers showed higher hot carcass weight (p

Despite a high volume of market (cull) dairy cows entering the food chain every year, beef from market dairy cows is largely considered insignificant when compared with beef from beef cattle in the market and is widely thought to be used for ground beef only. Our study aimed to evaluate the effects of feeding dairy market cows on a lactating TMR diet before slaughter on carcass and beef quality traits. Forty-three Holstein market cows were randomly assigned into 2 treatments: Fed or Direct. Fed cows (n = 22) were dried off, then fed a lactating cow TMR ration for approximately 60 d whereas Direct cows (n = 21) were sent directly to slaughter. Hot carcass weight (HCW) was used to calculate the dressing percentage (DP) together with the animals' body weight recorded when animals left the farm to go to the abattoir. At 24h post-mortem, the rib fat thickness (RFT) and rib eye area (REA) were measured by a certified grader. Afterward, rib samples were collected between the 12th -10th ribs from one side of the carcass and divided into 5 ribeye steaks. The first steak was used for intramuscular fat (IMF) content analysis by NIRS. The other 4 steaks were then aged for 7, 14, 21, or 28 d. Following aging, the steaks available were assessed for tenderness using the Warner-Bratzler Shear Force protocol. Data were analyzed by mixed linear regression to compare experimental groups for continuous outcomes. HCW of the Fed cows was higher than the Direct cows, with a mean HCW of 408.3 kg and 326.1 kg, respectively (SE ± 9.0). Average DP in Fed cows was 49.1%, compared with 42.5% in Direct cows (SE ± 0.69). The average percentage of IMF in Fed cows was 8.1% and in Direct cows was 5.0% (SE ± 0.43). Fed cows had a mean REA of 68.1 cm 2 and Direct cows had a mean of 57.7 cm 2 (SE ± 11.9). No differences were found for RFT. The steaks aged for 14 d resulted in meat with a mean shear force (SF) of 4.19 kg in Fed cows, while Direct cows had a mean SF of 6.28 kg (SE ± 0.29) Feeding market dairy cows for 60 d before slaughter enhanced carcass weight and yield, IMF content, and tenderness. These results indicate that approximately 60 d of feeding can improve the quality of market dairy cow meat and may help improve market cow value., (The Authors. Published by Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Abstract: The objective of this work was to evaluate the influence of lairage periods on the temperament, physiological indicators of stress, and meat quality of beef cattle. Thirty-two castrated Aberdeen Angus x Nellore crossbred steers were distributed into four lairage periods: 12, 18, 24, and 48 hours. The following variables were evaluated: serum levels of the physiological indicators of stress glucose and cortisol (upon arrival at the slaughterhouse, after the lairage period, and at bleeding), animal temperament (movement, resistance to approach, and aggressiveness), and meat quality (final pH, water-holding capacity, color parameters, and tenderness). With a longer lairage period, the temperament score was higher, indicating that the animals were more agitated and resistant to human approach. Serum cortisol and glucose levels correlate positively with animal temperament and negatively with meat quality. At bleeding, an increase was observed in glucose and cortisol levels, respectively, for lairage periods longer than 24 hours and of 12 hours. The lairage of 48 hours reduces meat tenderness and water-holding capacity.

Tenderness is one of the main characteristics of meat because it determines its price and acceptability. This is the first bibliometric study on the trend of research on the role of genes in meat tenderness. A total of 175 original and English-language articles published up to 2021 were retrieved from Scopus. The bibliometric analysis was carried out with VOSviewer (version 1.6.18, Eck and Waltman, Leiden, Netherlands) and complemented with the Analyze search results service from Scopus. Erroneous and duplicate data were eliminated, and incomplete information was added to standardize the results. Scientific production was evaluated by means of quantity, quality and structure indicators. As a first glance, 8.816% of authors have published more than 50% of papers mainly related to genes encoding the calpain (CAPN)-calpastatin (CAST) system and single nucleotide polymorphisms (SNPs). Among other findings, a strong link was found between the contribution of the main countries (led by the United States with) and their institutions (led by the USDA Agricultural Research Service with) to their gross domestic product. Most studies on the topic are published in the Journal of Animal Science, and other journals with high impact according to the number of citations and different metrics. Finally, when evaluating the most cited articles, the occurrence and association of the main keywords, it was confirmed that research is focused on the role of CAPN and CAST genes and of SNPs in beef tenderness. The change in science was emphasized; although marker-assisted selection is still used, genes have an infinitesimal effect on complex traits. Therefore, since about 2010, new research groups adopted genomic selection to evaluate dense panels of SNPs and better explain genetic variation in meat tenderness.

Yak is a rare breed of resources in Tibetan Plateau, with high protein and low-fat content, and has other important application value. Yaks are managed by herders and slaughtered in various ages, changing from three years to twelve years of age, and there has a significant difference on meat tenderness in different ages. This study was conducted to investigate the effects of age at harvest, ageing time and the correlation analysis to meat tenderness calpains activity. The work may be used to establish a classification system and grading standards for yak meat. Four groups were established as fewer than 3 years-old, 3-5 years-old, 5-7 years-old and more than 7-years old. The results demonstrated that the content of tenderness has significantly different (P

The Syrian Sumac (Rhus coriaria) is a widely used spice in the Arab world of attractive economic importance in food, cosmetic and pharmaceutical industries. Meat tenderness is one of the very most important factors for customers’ acceptability. The global objective of this study was to add an additional value to Sumac by evaluating its meat tenderizing effect. Crude sumac fruits were used to create three different extracts (aqueous, ethanolic and purified enzymatic extract). Pectoralis superficialis cuts were treated with the extracts and studied for their shear stress, pH, protein and fat contents and collagen. The hypothesis that Sumac could have a meat tenderizing effect was supported by our results showing a significant decrease in shear stress and protein content with increase in collagen solubility. Moreover, an effect on decreasing meat fat was detected, where the aqueous sumac extract decreased significantly the fat percentage in meat. The active enzymes in Sumac were shown to be variate in nature, lipase and protease, with a significant effect on collagen, thus proving Sumac’s possibility to be potentially used as a meat tenderizer.

Abstract Background Pre-slaughter stress (PSS) impairs animal welfare and meat quality. Dark, firm and dry (DFD) are terms used to designate poor quality meats induced by PSS. Protein phosphorylation can be a potentially significant mechanism to explain rapid and multiple physiological and biochemical changes linked to PSS-dependent muscle-to-meat conversion. However, the role of reversible phosphorylation in the response to PSS is still little known. In this study, we report a comparative phosphoproteomic analysis of DFD and normal meats at 24 h post-mortem from the longissimus thoracis (LT) bovine muscle of male calves of the Rubia Gallega breed. For this purpose, two-dimensional gel electrophoresis (2-DE), in-gel multiplex identification of phosphoproteins with PRO-Q Diamond phosphoprotein-specific stain, tandem (MALDI-TOF/TOF) mass spectrometry (MS), novel quantitative phosphoproteomic statistics and bioinformatic tools were used. Results Noticeable and statistically significant differences in the extent of protein phosphorylation were detected between sample groups at the qualitative and quantitative levels. Overall phosphorylation rates across significantly changed phosphoproteins were about three times higher in DFD than in normal meat. Significantly changed phosphoproteins involved a variable number of isoforms of 13 myofibrillar and sarcoplasmic nonredundant proteins. However, fast skeletal myosin light chain 2 followed by troponin T, F-actin-capping and small heat shock proteins showed the greatest phosphorylation change, and therefore they were the most important phosphoproteins underlying LT muscle conversion to DFD meat in the Rubia Gallega breed. Conclusions This is the first study reporting global meat phosphoproteome changes in response to PSS. The results show that reversible phosphorylation is a relevant mechanism underlying PSS response and downstream effects on meat quality. This research opens up novel horizons to unravel the complex molecular puzzle underlying muscle-to-meat conversion in response to PSS.

Abstract Background Traditional single nucleotide polymorphism (SNP) genome-wide association analysis (GWAA) can be inefficient because single SNPs provide limited genetic information about genomic regions. On the other hand, using haplotypes in the statistical analysis may increase the extent of linkage disequilibrium (LD) between haplotypes and causal variants and may also potentially capture epistastic interactions between variants within a haplotyped locus, providing an increase in the power and robustness of the association studies. We performed GWAA (413,355 SNP markers) using haplotypes based on variable-sized sliding windows and compared the results to a single-SNP GWAA using Warner-Bratzler shear force measured in the longissimus thorasis muscle of 3161 Nelore bulls to ascertain the optimal window size for identifying the genomic regions that influence meat tenderness. Results The GWAA using single SNPs identified eight variants influencing meat tenderness on BTA 3, 4, 9, 10 and 11. However, thirty-three putative meat tenderness QTL were detected on BTA 1, 3, 4, 5, 8, 9, 10, 11, 15, 17, 18, 24, 25, 26 and 29 using variable-sized sliding haplotype windows. Analyses using sliding window haplotypes of 3, 5, 7, 9 and 11 SNPs identified 57, 61, 42, 39, and 21% of all thirty-three putative QTL regions, respectively; however, the analyses using the 3 and 5 SNP haplotypes, cumulatively detected 88% of the putative QTL. The genes associated with variation in meat tenderness participate in myogenesis, neurogenesis, lipid and fatty acid metabolism and skeletal muscle structure or composition processes. Conclusions GWAA using haplotypes based on variable-sized sliding windows allowed the detection of more QTL than traditional single-SNP GWAA. Analyses using smaller haplotypes (3 and 5 SNPs) detected a higher proportion of the putative QTL.

Context: Many indices of feed efficiency for livestock have been proposed, but most are associated with differences in body composition and consequently affect meat quality. Aims: This study aimed to assess meat quality and lipid profile of intramuscular fat of Texel crossbred lambs classified by residual intake and gain (RIG). Methods: Seventy-seven non-castrated male Texel crossbred lambs (1/4 Pantaneira and 3/4 Texel) were assessed in a 2-year study. First year: Forty-seven lambs with initial bodyweight of 29.9 ± 5.5 kg. Second year: Thirty lambs with an initial bodyweight of 22.4 ± 3.3 kg. Lambs were confined in individual stalls for 70 days for the assessment of individual dry matter intake and average daily gain, being then slaughtered. The muscle Longissimus lumborum was removed for analyses. The RIG was obtained by: RIG = (−1 × residual feed intake) + residual gain. The data of meat quality and lipid profile from both years were grouped and analysed in a completely randomised design. Animals were classified into three RIG classes based on the s.d. of RIG variable. Efficient (n = 20) and inefficient (n = 22) animals were classified adopting ± 0.5 s.d. from RIG mean, and animals between these two groups were classified as intermediate (n = 35). Key results: No significant differences were observed between RIG classes regarding instrumental characteristics and proximate composition of the Longissimus lumborum muscle. We observed no differences between RIG classes for concentrations of saturated (SFA), monounsaturated (MUFA), and polyunsaturated fatty acids (PUFA), as well as for the total sum of SFA, MUFA, and PUFA of intramuscular fat, with 40.9, 54.1, and 5.1% of total FA, respectively. The MUFA:SFA ratio, PUFA:SFA ratio, atherogenic and thrombogenic index were also not influenced by RIG classes. Conclusions: There were no differences in meat quality and lipid profile of intramuscular fat between animals classified based on RIG. Implications: Improvements provided by using RIG to identify efficient and faster-growing lambs could assist in reducing feed and labour investments in the production system through an early slaughter without having negative impacts on meat quality. Measuring residual intake and gain (RIG) allows identification of animals that present higher growth rates and proportionally lower feed intake than expected, without leading to an increase in adult bodyweight. The identification of efficient animals by RIG can assist in the early slaughter without having negative impacts on meat quality. The RIG has a great potential for improvements in the sheep production system, such as reductions in feed and labour investments due to a shortening in the production cycle. [ABSTRACT FROM AUTHOR]

The objective of this study was to investigate the mechanism underlying nitric oxide (NO)-induced hypoxia-inducible factor-1α (HIF-1α) and its impact on yak muscle tenderness during post-mortem aging. The Longissimus thoracis et lumborum (LTL) muscle of yak were incubated at 4 °C for 0, 3, 6, 9, 12, 24, and 72 h after treatment with 0.9% saline, NO activator, or a combination of the NO activator and an HIF-1α inhibitor. Results indicated that elevated NO levels could increase HIF-1α transcription to achieve stable expression of HIF-1α protein ( P < 0.05). Additionally, elevated NO triggered HIF-1α S-nitrosylation, which further upregulated the activity of key glycolytic enzymes, increased glycogen consumption, accelerated lactic acid accumulation, and decreased pH ( P < 0.05). These processes eventually improved the tenderness of yak muscle during post-mortem aging ( P < 0.05). The results demonstrated that NO-induced activation of HIF-1α S-nitrosylation enhanced glycolysis during post-mortem aging and provided a possible pathway for improving meat tenderness.

Diacylglycerol acyltransferase-1 (DGAT1) has been recognised as one of the functional genes during fat deposition and closely related to meat quality. It is well known that yak meat has low intramuscular fat (IMF) and poor tenderness, influencing the purchase decision for consumers. In this study, the variations of DGAT1 gene were detected using polymerase chain reaction single-stranded conformational polymorphism (PCR-SSCP) analysis so as to ascertain the association of DGAT1 variation with yak carcase and meat quality traits. Two variants (A1 and B1) in intron 1 – exon 2 and another three variants (A2 to C2) in intron 15 – exon 17 were identified in the yaks investigated. Three sequence variations (c.192-117 G > A, c.1252-23 C > T and c.1339 C > T) were detected among these variants, with c.192-117 G > A located in intron 1, c.1252-23 C > T located in intron 15 and c.1339 C > T located in exon 17. The mutation c.1339 C > T resulted in an amino acid change (p. Arg 447 Cys). Variants A1 and B2 were associated with a decrease and increase in Warner–Bratzler shear force (WBSF) (p = 0.027 and p < 0.001), respectively. Variant C2 was associated with a decrease in WBSF and hot carcase weights (HCW) (p = 0.001 and p = 0.037, respectively). The presence of haplotype H3 and absence of H5 were highly associated with a decrease in WBSF (p < 0.05). These finding suggested that the variations in DGAT1 could be potential targets for gene-assisted selection to improve meat tenderness in Gannan yak. Three SNPs were identified in the DGAT1 gene in Gannan yak. Variants (A1, B2 and C2) and haplotypes (H3 and H5) have a significant influence on Warner–Bratzler shear force (WBSF) in Gannan yak. DGAT1 variations may have potential in selection for improving meat tenderness in Gannan yaks. [ABSTRACT FROM AUTHOR]

The aim of this review was to summarize the histological, physical, chemical and microbial aspects and ways to stop the fluctuation in meat quality in addition to enhance its sensory quality using electrical stimulation. The low-voltage electrical stimulation and high-voltage electrical stimulation were employed. Electrical stimulation improves quality of poultry meat by reducing shear, increasing Sarcomere length, and reducing the diameter of muscle fibers. Low-voltage electrical stimulation affects voltages (120 volts directly in the nervous system, while high voltages were more than enough) to remove the polarization of the cover and produce a dense physio-chemical response in the muscles that had a direct effect. Electrical stimulation and injection with salts of sodium chloride and calcium chloride in the carcasses of female goats improved the tenderness of the meat. It was found that electrical stimulation accelerated the development of rigor mortis. Although electrical stimulation reduces breast meat shear, there was limited information about the effects of electrical stimulation on the other quality attributes of poultry meat and the results vary with quality attribute and differ from experimental conditions High voltage (higher than 120 volts) electrical stimulation improved meat quality and decreased the pH. Low voltages (below 120 volts) are used to ensure the safety of workers and give the desired results when used in commercial applications.

Various meat quality characteristics of six muscles (Longissimus thoracis et lumborum (LTL), Semimembranosus (SM), Biceps femoris (BF), Supraspinatus (SS), Infraspinatus (IS), Semitendinosus (ST)) from large-frame Boer Goats (BG) and Indigenous Veld Goats (IVG: Cape Speckled and the Cape Lob Ear) were studied. Weaner male BG (n = 18; 10 bucks and 8 wethers) and IVG (n = 19; 9 bucks and 10 wethers) were raised on hay and natural grass, and on a commercial pelleted diet to a live weight of 30–35 kg. All goats were slaughtered at a commercial abattoir and the dressed carcasses were chilled at 4 °C within 1 h post mortem. The muscles were dissected from both sides 24 h post mortem and aged for 1 d and 4 d. Variations in meat characteristics such as ultimate pH, water holding capacity (WHC), % purge, myofibril fragment length (MFL), intramuscular fat (IMF), connective tissue characteristics, and Warner-Bratzler shear force (WBSF) were recorded across muscles. Bucks had higher lightness (L*) and hue-angle values, whereas wethers had increased redness (a*) and chroma values. The muscle baseline data will allow informed decisions to support muscle-specific marketing strategies, which may be used to improve consumer acceptability of chevon.

Abstract: The objective of this work was to quantify heat shock proteins (HSP) 27 and 70 in the Longissimus dorsi muscle of cattle during aging and to check their potential as biomarkers for meat quality. A total of 191 steers ½ South African Simmental x ½ Nellore (16-18 months, 391.7±99.7 kg), castrated, and feedlot finished were used. Meat quality was measured by pH, color, cooking loss, and shear force (SF) at 1 and 14 days of aging time. HSP27 and HSP70 were quantified according to the SF values in the more and less tender meat groups, with 20 samples each, for each aging time. HSP27 concentrations in more and less tender meat decrease from 1 to 14 days of aging, and do not differ when evaluated at the same period. HSP70 concentrations in more tender meat increase during aging, and, in less tender meat, there is no difference between periods or at the same period. The correlations between the HSP27 and HSP70 concentrations and meat quality characteristics are low for South African Simmental x Nellore, which indicate the low potential of HSP as biomarkers for these traits, especially for meat tenderness.

The poultry industry has attempted to improve carcass chilling efficiency, meat quality, and product safety. The purpose of this research was to investigate the effects of subzero saline chilling on carcass chilling, breast fillet tenderness, andmicrobial safety.After evisceration, broiler carcasses were chilled using ice slurry control (0% NaCl/0.5)C) or subzero saline solutions (3% NaCl/21.8)C and 4% NaCl/22.41)C). Broiler carcasses in the subzero saline solutions were chilled efficiently and reduced the chilling time by 11% in 3% NaCl/21.8)C and 37% in 4% NaCl/22.41)C over the ice slurry chilling. The breast fillets of broiler carcasses in 4%NaCl/22.41)Cwere significantly tenderized than those in water control (P, 0.05), with an intermediate value observed in 3% NaCl/21.8)C. Before chilling, broiler carcasses possessed mesophilic aerobic bacteria, Escherichia coli, and total coliforms for 3.81, 0.78, and 1.86 log cfu/g, respectively, whichwere significantly reduced after chilling in 3% NaCl/21.8)C or 4% NaCl/22.41)C solution over thewater control (P,0.05), except the mesophilic aerobic bacteria. Based on these results, chilling of boiler carcass in 4% NaCl/21.8)C solution appears to improve carcass chilling efficiency, meat tenderness, and bacterial reduction for E. coli and total coliforms. [ABSTRACT FROM AUTHOR]

Objective: The aim of the present study was to determine the effect of supplementing pasturefinished steers with corn silage on the expression level of the calpain system proteins and beef tenderization. Methods: Thirty Braford steers grazing on summer pasture were used for the study. For 120 days fifteen animals were supplemented with corn silage at 1% of body weight per head per day (Suppl) whereas the remaining 15 steers only received pasture (Contr). Carcass and meat traits were evaluated and compared between groups. Gene expression and activities of proteases (calpain 1 and calpain 2) and inhibitor (calpastatin) were measured using real-time polymerase chain reaction and casein zymography. Results: Carcass and meat traits were significantly different between feeding systems. Supplemented steers showed higher hot carcass weight (p<0.01), fat content (p = 0.02), and Warner- Bratzler shear force (p = 0.03). Furthermore, the control group showed higher protease:inhibitor ratios, at mRNA (p = 0.01) and protein levels (p<0.10). Warner-Bratzler shear force and mRNA calpains:calpastatin ratio were associated in both feeding systems (p<0.01). Conclusion: Based on the results obtained in the study, beef tenderness differences among finishing strategies could be modulated through differential expression of the calpain system proteins. [ABSTRACT FROM AUTHOR]