Development of the Caecal Microbiota in Three Broiler Breeds

Area of Science:

• Animal Science
• Microbiology
• Gut Health

Background:

• The caecal microbiota is crucial for chicken metabolism and immune system development.
• Understanding its succession aids in optimizing gut health through interventions like probiotics.

Purpose of the Study:

• To detail the developmental succession of the caecal microbiota in broiler chickens from 0 to 42 days post-hatch.
• To compare microbiota development across three broiler breeds: Cobb 500, Hubbard JA87, and Ross 308.

Main Methods:

• Collected caecal mucus and lumen samples from 0 to 42 days post-hatch across three broiler breeds.
• Extracted DNA and performed high-throughput Illumina sequencing of the 16S rRNA gene's V4 hypervariable region.
• Analyzed amplicon sequence variants (ASVs) to characterize microbial community composition and succession.

Main Results:

• Early caecal microbiota (0-14 days) showed low diversity, dominated by Bifidobacteriaceae, Lachnospiraceae, Bacteroidaceae, and Burkholderiaceae.
• Later colonizers (from 14 days) included Ruminococcaceae, Clostridiales vadin BB60 group, Christensenellaceae, and Bacillaceae, with Bacteroidaceae, Lachnospiraceae, and Ruminococcaceae abundant by 42 days.
• Significant differences in microbiota composition were observed between Ross and Cobb, and Ross and Hubbard breeds at 42 days post-hatch, with distinct ASV preferences for mucus versus lumen environments.

Conclusions:

• Chicken caecal microbiota undergoes significant succession from hatch to 42 days post-hatch.
• Microbiota composition varies between broiler breeds, suggesting potential breed-specific gut health implications.
• Further research is needed to link these microbial differences to specific host functions and performance outcomes.