Chinese consumer preference for beef with geographical indications and other attributes

Integrating metabolomics and transcriptomics to analyze differences in muscle mass and flavor formation in Gayal and yellow cattle

Beef flavor is affected by muscle metabolites and their related regulatory genes, and the molecular regulatory mechanisms vary among different beef breeds. To provide some new ways to improve meat quality and cattle breed improvement, 24-month-old Gayal (n = 8) and yellow cattle (n = 8) were selected for comparison in this study. The result revealed that the longissimus dorsi muscle fiber diameter, protein content and a-value of Gayal were significantly higher than that of yellow cattle, but the fat content was lower than that of yellow cattle. Furthermore, Gayal meat contained notably higher levels of polyunsaturated fatty acids (PUFA) and n-3PUFA than that of yellow cattle, and also had better levels of flavor amino acids (FAAs) and sweet amino acids (SAAs), which contribute to the flavor of beef. Through comprehensive analysis of transcriptomics and metabolomics, we detected a total of 109 markedly different metabolites (DEMs) and 1,677 differentially expressed genes (DEGs) in the pectoral muscles of the two breeds. Further analysis indicated that amino acid and lipid metabolism might be the key factors contributing to the differences in meat quality and flavor between Gayal and yellow cattle, involving metabolites such as L-2-aminobutyric acid, L-glutamic acid, L-glutamine, L-serine, betaine, pantothenic acid, and taurine. Through correlation analysis, we identified genes highly associated with flavor amino acids (GSTM3, GSTT2), muscle development (FGF10, EIF4EBP1, PPP2R2C), and lipid metabolism (CYP4A22, ACOX3, PLIN1, ADH6, CNDP1, LPAR3, BRCA1, ADIPOQ, FABP3) related essential regulatory genes and constructed a gene-metabolite interaction network for meat quality and flavor formation in Gayal. In summary, it was shown that significant differences in muscle metabolites between Gayal and yellow cattle, especially in amino acid and lipid metabolism, may be the major reason for the differences in quality and flavor between the two types of beef. This study provides a theoretical basis for further exploring the molecular regulatory mechanisms of the differences in beef quality and flavor between Gayal and yellow cattle, and provides a reference for the development and genetic breeding of high-quality cattle breeds.

Integrated Transcriptomic Analysis of Liver and Muscle Tissues Reveals Candidate Genes and Pathways Regulating Intramuscular Fat Deposition in Beef Cattle

Intramuscular fat (IMF) content in beef cattle is a critical determinant of beef meat quality, as it positively influences juiciness, tenderness, and palatability. In China, the crossbreeding of Wagyu and Angus is a prevalent method for achieving a better marbling level. However, the molecular mechanisms governing IMF regulation in these crossbreeds remain poorly understood. To elucidate the mechanism of IMF deposition in these crossbred cattle, we conducted a comparative transcriptomic analysis of longissimus dorsi muscles and livers from cattle with divergent IMF content. RNA-seq revealed 940 and 429 differentially expressed genes (DEGs) in the liver and muscle, respectively, with 60 genes co-differentially expressed (co-DEGs) in both tissues. Functional enrichment highlighted lipid metabolism pathways including fatty acid β-oxidation, PPAR signaling, and glycerolipid metabolism. A total of eleven genes including ACAA2, ACADL, ACOX2, CPT1B, CPT2, LPL, SLC27A1, ACAT1, GK, ACOX3, and ACSM5, were screened as key candidate genes for IMF deposition. A "liver-muscle" regulatory network of IMF deposition was built to illustrate the tissues' interaction. The reliability of the transcriptomic data was verified by quantitative reverse real-time PCR (qRT-PCR). Our findings provide novel molecular markers for increasing the IMF content and accelerating the genetic improvement of beef quality traits in crossbred cattle.

Future cattle production: Animal welfare as a critical component of sustainability and beef quality, a South American perspective

The demand for animal protein is rising, increasing pressure on animal production systems and ecological resources. Ethical and environmental concerns are also growing worldwide, pushing for more sustainable food production systems. The international scientific community has raised concerns about misinformation regarding meat production processes and their harmful impact on the environment, animal welfare and human health consumption. It is crucial to provide accurate information based on science, implement an active communication strategy, and foster collaboration across the meat supply chain to demonstrate that livestock farming is part of the solution to climate change and sustainability issues. As a fundamental pillar of sustainability, animal welfare plays a crucial role in this scrutiny. The "social license to farm" hinges on animal welfare issues and those related to climate change, the environment and biodiversity. Animal welfare is gaining relevance in the market of farm animals and their products, shaping a nation's standing in the international community. Considering the potential advantages of the Southern cone of South America production systems regarding sustainability and animal welfare, several countries prioritise them in their science, technology transfer, innovation, and public policy agendas. Scientific research indicates that implementing effective animal handling and welfare practices has a demonstrably positive impact on individual animal temperament, the quality of the human-animal relationship, overall productivity, and meat quality while reducing the risks of accidents. Caring for the welfare of animals is not only a moral imperative but can also be a business decision that benefits all stakeholders.

Comprehensive Evaluation of Nutritional, Physicochemical, and Volatile Profiles of Selected Bovine Head Muscles

This study analyzed the nutritional composition, physicochemical properties, and volatile profiles of three major bovine head muscles-medial pterygoid, masseter, and buccinator-to reduce byproduct resource waste and increase the utilization rate of bovine head to establish a foundation for its industrial use. Compared to tenderloin, which is popular among consumers, these head muscles were found to be rich in collagen (4.90-13.1 mg/g), low in fat (0.39-1.61%), and abundant in free amino acids (143.93-223.00 mg/100 g). Their compact fiber structures, with minimal gaps between myocytes, resulted in lower cooking and press losses, making them suitable for various production processes. Notably, the medial pterygoid and masseter muscles contained high levels of polyunsaturated fatty acids (PUFAs) and lower saturated fatty acids (SFAs), with a PUFA/SFA ratio exceeding 0.45. The buccinator muscle, while containing more volatile organic compounds associated with undesirable odors and bitter amino acids, was not indicative of spoilage. Overall, this study confirmed that bovine head muscles possess high collagen, low fat, and diverse nutritional qualities, making them suitable as premium raw materials for value-added meat products, and their returns will be most economically equal to the meat derived from cattle.

Integrative metabolomics and transcriptomics analysis revealed specific genes and metabolites affecting meat quality of chickens under different rearing systems

Different rearing systems have varying effect on animal welfare and meat quality of poultry. Currently, there are no established standards for the rearing systems of Chinese indigenous chickens. Our study aimed to investigate the effects of different rearing systems on the meat quality, gene profiles, and metabolites of Chinese indigenous chickens (Nanchuan chicken). 10-wk-old Nanchuan chickens (n=360) were randomly divided into 3 groups (cage, net, and free-range groups), with 6 replicates per group (20 chickens per replicate). The experiment lasted for 12 wk. At 154-days-old, 36 healthy chickens (6 males and 6 females per group) were randomly selected, euthanized, and their breast muscles were collected to assess the meat quality parameters and histomorphological characteristics. Additionally, breast muscles from 18 random hens (3 males and 3 females per group) were used for metabolomics and RNA-seq analysis. The results showed that rearing systems significantly affected the meat quality and myofiber characteristics. The meat quality of breast muscles from free-range chickens was superior to that of caged chickens, characterized by more tender meat and smaller myofiber cross-sectional areas. Integrative metabolomics and transcriptomics analysis revealed that the differentially expressed genes of chicken breast muscles were primarily involved in the myofiber differentiation. Mechanically, the improved meat quality of breast muscle in free-range chickens were mainly associated with enhanced skeletal muscle differentiation facilitated by fibromodulin, increased levels of up-regulated Acetyl-L-carnitine and Propionylcarnitine level, and decreased levels of Nonanoic acid and Elaidic acid abundance (Graphical abstract). This provides a comprehensive understanding of the most effective and sustainable breeding, production, and rearing systems for Chinese indigenous chickens. It also contributes to the current knowledge of the molecular mechanisms underlying the effects of rearing systems on growth performance and meat quality of chickens.

Microbial Diversity and Community Structure of Chinese Fresh Beef during Cold Storage and Their Correlations with Off-Flavors

To investigate the diversity and dynamics of microorganisms in Chinese fresh beef (CFB) without acid discharge treatment during cold storage, high-throughput sequencing was employed to analyze the CFB refrigerated for 0, 3, 7, and 10 days. The results showed that the community richness of the fungi and bacteria decreased significantly. However, the diversity decreased in the early stage and increased in the later stage. At the phylum level, Ascomycota (74.1-94.1%) and Firmicutes (77.3-96.8%) were the absolutely dominant fungal and bacterial phyla. The relative abundance of both fungal and bacterial phyla displayed a trend of increasing and then decreasing. At the genus level, Candida (29.3-52.5%) and Lactococcus (19.8-59.3%) were, respectively, the dominant fungal and bacterial genera. The relative abundance of Candida showed a trend of increasing and then decreasing, while Lactococcus possessed the opposite trend. KEGG metabolic pathways analysis suggested that carbohydrate metabolism, membrane transport, and amino acid metabolism were the major metabolic pathways of bacteria. Bugbase prediction indicated the major microbial phenotype of bacteria in CFB during cold storage was Gram-positive (17.2-31.6%). Correlation analysis suggested that Lactococcus, Citrobacter, Proteus, and Rhodotorula might be the main microorganisms promoting the production of off-flavor substances in CFB. This study provides a theoretical basis for the preservation of Chinese fresh beef.