Unveiling the Kadaknath Gut Microbiome: Early Growth Phase Spatiotemporal Diversity

The early growth phase is a critical period for the development of the chicken gut microbiome. In this study, the spatiotemporal diversity of the gastrointestinal microbiota, shifts in taxonomic composition, and relative abundances of the main bacterial taxa were characterized in Kadaknath, a high-value indigenous Indian chicken breed, using sequencing of the V3–V4 region 16S rRNA gene. To assess microbiome composition and bacterial abundance shifts, three chickens per growth phase (3, 28, and 35 days) were sampled, with microbiota analyzed from three gut regions (crop, small intestine, and ceca) per bird. The results revealed Firmicutes as the most abundant phylum and Lactobacillus as the dominant genus across all stages. Lactobacillus was particularly abundant in the crop at early stages (3 and 28 days), while the ceca exhibited a transition towards the dominance of genus Phocaeicola by day 35. Microbial richness and evenness increased with age, reflecting microbiome maturation, and the analyses of the microbial community composition revealed distinct spatiotemporal differences, with the ceca on day 35 showing the highest differentiation. Pathogen analysis highlighted a peak in poultry-associated taxa Campylobacter, Staphylococcus, and Clostridium paraputrificum in 3-day-old Kadaknath, particularly in the small intestine, underscoring the vulnerability of early growth stages. These findings provide critical insights into age-specific microbiome development and early life-stage susceptibility to pathogens, emphasizing the need for targeted interventions to optimize poultry health management and growth performance.