Study on Changes in Gut Microbiota and Microbiability in Rabbits at Different Developmental Stages

In recent years, research has shown that animals' gut microbiota can regulate various physiological functions such as nutrition, metabolism, and immunity, and play an indispensable role in maintaining host gut health. At present, there are few reports on the establishment of rabbits' gut microbiota and its relationship with the host. To clarify the colonization of rabbits' gut microbiota, the changes in species during development, and the relationship between gut microbiota and rabbits' growth and development, this study determined the 16s rRNA of gut microbiota in rabbits of different age groups and preliminarily explored the changes in the types of gut microbiota during the colonization process. Six amplicon sequence variants (ASVs) that significantly affect body weight were obtained. The research results provide a firm theoretical basis for maintaining gut health and constructing new methods for rabbit breeding. This study used feces from 0-day-old (36 rabbits), 10-day-old (119 rabbits), and 60-day-old (119 rabbits) offspring rabbits and their corresponding female rabbits (36 rabbits) as experimental materials. Using 16s rRNA sequencing, the study analyzed the types and changes of gut microbiota in rabbits at different growth and development stages, as well as the correlation between gut microbiota composition and the weight of 60-day-old rabbits. All experimental rabbits were placed in the same rabbit shed. Juvenile rabbits were fed solid feed at 18 days of age and weaned at 35 days of age. In addition to identifying the dominant bacterial phyla of gut microbiota in rabbits at different age stages, it was found that the abundance of Clostridium tertium and Clostridium paraputrificum in all suckling rabbits (10-day-old) was significantly higher than that in rabbits fed with whole feed (60-day-old) (p < 0.05), while the abundance of Gram-negative bacterium cTPY13 was significantly lower (p < 0.05). In addition, Fast Expected Maximum Microbial Source Tracing (FEAST) analysis showed that the contribution of female rabbits' gut microbiota to the colonization of offspring rabbits' gut microbiota was significantly higher than that of unrelated rabbits' gut microbiota (p < 0.05). The contribution of female rabbits' gut microbiota to the colonization of gut microbiota in 0-day-old rabbits was significantly higher than that to the colonization of gut microbiota in the 10- and 60-day-old rabbits (p < 0.05). Finally, the correlation between gut microbiota composition and body weight of 60-day-old rabbits was analyzed based on a mixed linear model, and six ASVs significantly affecting body weight were screened. The above results provide important theoretical and practical guidance for maintaining gut health, improving growth and development performance, and feeding formulation in rabbits.