Comparative study on the rumen microbial communities and functions between Wagyu and Holstein calves

Area of Science:

• Animal Science
• Microbiology
• Ruminant Nutrition

Background:

• Rumen microbiota development is crucial for calf nutrition and growth.
• Breed-specific differences in rumen microbial communities may impact health and productivity.
• Understanding these dynamics aids in optimizing feeding strategies for different cattle breeds.

Purpose of the Study:

• To comparatively analyze the dynamic changes in rumen microbial community structure and function in Wagyu and Holstein calves.
• To investigate breed-specific differences in rumen microbial succession from 3 to 6 months of age.
• To correlate microbial changes with potential impacts on calf development and metabolism.

Main Methods:

• Metagenomic sequencing of rumen fluid from Wagyu and Holstein calves (n=5 each) aged 3-6 months.
• Assessment of microbial composition (phylum, genus), alpha diversity (Shannon, Simpson, ACE, Chao1), and functional pathways (KEGG).
• Standardized diet and free access to feed and water for all calves.

Main Results:

• Dominant taxa abundance decreased with age in both breeds, more significantly in Wagyu calves.
• Wagyu calves exhibited significantly higher alpha diversity indices (Shannon, ACE, Chao1) from 4-6 months of age compared to Holsteins.
• At 6 months, Wagyu calves showed reduced metabolism-related genes and increased genes for cellular and genetic processing compared to Holsteins.

Conclusions:

• Breed-specific differences exist in rumen microbiota succession and functional maturation.
• Holstein calves demonstrate earlier and more stable rumen metabolic functions.
• Wagyu calves undergo a more dynamic microbial selection process, suggesting distinct developmental trajectories.