The meat quality of different pig breeds is associated with their different muscle tissue physiological processes, which involves a large variety of genes related with muscle fat and energy metabolism. Understanding the differences of biological processes of muscle after slaughter is helpful to reveal the meat quality development of different breeds. Therefore, eight native Large Black pigs (BP), with high fat content in meat, and seven cross-bred commercial pigs (CP), which had a high feed efficiency with high lean meat, were used to investigate the differences in their meat quality and RNA transcriptomes. The average daily gain (ADG) and hot carcass weight (HCW) of CP were higher than BP, but the back-fat thickness of BP was higher than CP (p < 0.05). The CP had higher a* (redness) but lower h (hue angle) than BP (p < 0.05). The metmyoglobin (MMb) percentage of CP was higher (p < 0.05) than BP. The fat content and oxygen consumption of longissimus dorsi (LD) muscles in BP were higher (p < 0.05) than CP. BP had higher monounsaturated fatty acids (MUFA) content, but CP had higher polyunsaturated fatty acids (PUFA) content (p < 0.05). The RNA-seq data highlighted 201 genes differentially expressed between the two groups (corrected false discovery rate (FDR) p < 0.05), with 75 up-regulated and 126 down-regulated genes in BP compared with CP using the fold change (FC). The real-time PCR was used to validate the results of RNA-seq for eight genes, and the genes related to lipid and energy metabolism were highly expressed in BP (p < 0.05). Based on the results, BP had superior intramuscular fat content to CP, while the growth performance of CP was better, and the transcriptomic differences between these two groups of pigs may cause the meat quality and growth performance variance.

Intramuscular fat (IMF) content serves as the key determinants of meat quality. Emerging evidence indicates that gut microbiota and their metabolites significantly influence IMF deposition levels by modulating host lipid metabolism through multiple pathways, positioning microbial regulation as a pivotal target for meat quality improvement. However, existing studies remain fragmented, predominantly focusing on isolated mechanisms or correlations without a systematic view of the regulatory network. This review consolidates the core mechanisms through which microbiota-derived metabolites including short-chain fatty acids, bile acids, branched-chain amino acids, trimethylamine N-oxide, tryptophan derivatives, succinate, polyamines etc., regulate IMF deposition and proposes a targeted intervention framework, the “gut microbiota/metabolites-IMF axis”. By integrating these insights, we provide a theoretical foundation and define practical research pathways to assess the potential of microbial-based strategies for improving meat quality in swine production.

To investigate the prevalence and pathogenic characteristics of avian reovirus (ARV) in the Xinjiang region of China, this study collected suspected joint tissue samples from broiler farms across different areas of the Taikun Group. The samples were subjected to virus isolation, RT-PCR analysis, sequence analysis, in vitro replication assays, and pathogenicity assessments in specific pathogen-free (SPF) chicken embryos and chickens. The results revealed the isolation of a chicken-derived ARV epidemic strain, designated as ARV xj-1.1. The virus-induced cytopathic effects (CPEs) in LMH cells and the time required to observe CPEs significantly decreased with serial blind passages. Pathogenicity testing demonstrated that ARV xj-1.1 is highly virulent to SPF chicken embryos and chickens. Inoculation of SPF chicken embryos resulted in a 100% mortality rate, while inoculation of 1-day-old SPF chicks caused significant swelling of the footpads. In conclusion, this study successfully isolated an epidemic strain of avian reovirus, providing a valuable theoretical basis for understanding the genetic evolution and epidemiology of ARV variants in the Xinjiang region.