Meat Quality Characteristics of Mongolian Horses in Inner Mongolia: Regional Superiority and Transcriptomic Insights into Tenderness Differences Between Muscular Locations.

Overview

• This study investigated the meat quality differences of Mongolian horses across three regions and between different muscle sites within the Inner Mongolia region of China.
• It combined chemical, mineral, fatty acid analyses with transcriptomic profiling to identify factors contributing to variations in meat tenderness and quality.

Study Design and Sample Collection

• A total of 50 two-year-old male Mongolian horses (body weight ~300 ± 50 kg) were examined.
• 30 horses came from three regions: Bulgan province Mongolia (BPM), Tuv province Mongolia (TPM), and Inner Mongolia China (IMC), with 10 horses from each region for regional comparisons.
• An additional 20 horses from IMC were used to study meat quality differences between muscle locations – forelimb (FL) and hindlimb (HD).

Chemical Composition and Mineral Content Findings

• Mongolian horses from the Inner Mongolia China (IMC) region exhibited:
  • Highest levels of selenium (Se), iron (Fe), fatty acids C17:1, C18:2n6c, C18:3n3, total polyunsaturated fatty acids (∑PUFA), PUFA/SFA ratio, n-3 and n-6 PUFA (all statistically significant with p<0.05 or p<0.01).
  • Lowest levels of saturated fatty acids C15:0 and C16:0.
• The Tuv province Mongolia (TPM) horses had the highest calcium (Ca) content.
• The Bulgan province Mongolia (BPM) horses showed the highest total saturated fatty acids (∑SFA).

Muscle Site Differences in Meat Quality (Within IMC Region)

• Forelimb (FL) muscle displayed:
  • Higher color values a* (redness) and b* (yellowness).
  • Higher mineral contents of iron (Fe) and zinc (Zn).
  • Higher content of fatty acid C17:1.
  • Lower shear force values and drip loss, indicating better tenderness and water-holding capacity.
• Hindlimb (HD) muscle exhibited:
  • Higher pH and cooking loss.
  • Higher lightness value (L*), suggesting paler meat color.

Transcriptomic Insights and Molecular Pathways

• RNA sequencing detected 513 differentially expressed genes (DEGs) between FL and HD muscles.
• Though the gene names were not explicitly provided in the summary, some candidate genes related to meat quality and lipid metabolism were highlighted as important in the study.
• KEGG pathway enrichment analysis showed significant involvement of:
  • cGMP-PKG signaling pathway
  • Glycerophospholipid metabolism pathway
  • PPAR signaling pathway (known to regulate lipid metabolism)

Conclusions and Implications

• The study concluded that Mongolian horses from the Inner Mongolia China region exhibit superior meat quality traits and flavor characteristics compared to other regions studied.
• Within horses from IMC, the forelimb muscles showed better meat tenderness and quality biomarkers than the hindlimb muscles.
• The identification of key genes and molecular pathways related to meat quality advances understanding of muscle-specific mechanisms affecting tenderness and nutritional profiles.
• The variations identified in nutrient composition and physicochemical properties support future development of:
  • Quality grading systems specific to regional and muscle-site differences.
  • Targeted nutritional and dietary applications for horse meat.
  • Optimized meat processing approaches for Mongolian horse meat products.