Meat Quality Differences Correlated with Rumen Microbiota and Lipid Metabolism in Beef Cattle vs. Castrated Cattle

Area of Science:

• Animal Science
• Microbiology
• Metabolomics

Background:

• Intramuscular fat (IMF) is crucial for meat quality, influenced by lipid metabolism.
• The gastrointestinal microbiota's role in lipid metabolism and its connection to beef quality are not fully understood.

Purpose of the Study:

• To investigate how castration affects rumen microbiota composition and its subsequent impact on muscle lipid metabolism and beef quality traits.
• To elucidate the microbial-metabolite-host phenotype axis in relation to castration and beef quality.

Main Methods:

• Comparative study of intact vs. castrated Xinjiang Brown Beef cattle (n=22).
• Utilized in vivo ultrasonography, slaughter trials, rumen microbiome diversity analysis, and metabolomics.
• Statistical analysis adjusted for covariates like body weight, backfat thickness, and IMF content.

Main Results:

• Castration significantly altered rumen microbial composition and diversity (alpha and beta).
• Castration led to higher live weight, carcass weight, backfat thickness, and IMF content, but lower dressing percentage and shear force.
• Specific microbial genera (e.g., Anaeroplasma, Eubacterium uniforme) and metabolites (e.g., hydroxy fatty acids, docosapentaenoic acid) were identified as key regulators influenced by castration, impacting IMF and beef quality traits.

Conclusions:

• Castration regulates muscle lipid metabolism by reshaping the rumen microbial community.
• The rumen microbiota-metabolite axis plays a critical role in mediating castration's effects on beef quality.
• Findings identify potential targets for optimizing beef quality through modulation of rumen microbiota.