Relationships between microflora and caecal fermentation in rabbits before and after weaning

Area of Science:

• Microbiology
• Animal Science
• Biochemistry

Background:

• The rabbit caecum harbors a complex microbial ecosystem crucial for digestion.
• Understanding the dynamics of this microbiota during early development is essential for rabbit health and nutrition.

Purpose of the Study:

• To investigate the changes in microbiological and biochemical parameters of rabbit caecal content from 15 to 49 days of age.
• To correlate these changes with age, diet (pre- and post-weaning), and specific microbial populations.

Main Methods:

• Sequential slaughter of rabbits at different ages (15-49 days).
• Analysis of caecal content for ammonia, pH, Escherichia coli counts, total volatile fatty acids (VFA), and microbial flora (anaerobic, amylolytic, cellulolytic).
• Discriminant analysis to identify relationships between age, microflora, and fermentation parameters.

Main Results:

• Ammonia levels decreased significantly between days 29 and 32, with lower post-weaning levels.
• Escherichia coli counts decreased up to weaning.
• Total VFA concentration increased significantly by day 25 and then stabilized.
• Shifts in VFA proportions (propionate, BCFA, valeric acid) were observed with solid feed introduction.
• Anaerobic and amylolytic flora counts were high early on, while cellulolytic flora remained low.
• Discriminant analysis linked specific flora types to age, feeding, and fermentation products.

Conclusions:

• Rabbit caecal microbiota and fermentation undergo significant changes during the post-weaning period.
• Dietary transitions and age are key drivers of these microbial and biochemical shifts.
• Specific microbial communities are associated with distinct fermentation profiles and host-associated factors.