Abstract

Background:
Gut microbiota plays an important role in the digestive system of ruminants, affecting the health status of Hu sheep and their development and production traits. Factors such as gender, age, diet, and probiotic formulations may influence their compositions.

Aim:
This study aimed to investigate the morphological changes in the gastrointestinal tract and gut microbiota dynamics during postnatal development of Hu lambs and evaluate the effects of probiotic supplementation.

Methods:
During the 60-day experiment, rumen, duodenum, jejunum, and ileum samples were collected at 2 h, 20 days, and 55 days after birth. High-throughput 16S rRNA gene sequencing was employed to analyze microbial diversity, and morphological analysis was conducted to compare differences in the digestive tract surface tissues.

Results:
The results indicated that the length of the rumen papillae and the height of the villi in the jejunum and ileum continued to increase with increasing age. The overall diversity of the gut microbiota exhibited a gradual upward trend. The microbial diversity indices were higher in the experimental group than in the control group at corresponding time points (p > 0.05). The number of beneficial bacteria, such as Ruminococci, increased, whereas the number of potentially pathogenic bacteria, such as Escherichia spp., decreased.

Conclusion:
Probiotic supplementation promotes early gastrointestinal tract development, enhances the colonization of beneficial bacteria, and improves microbial diversity in Hu lambs.

Key words: Hu lambs; Probiotic formulations; 16S rRNA gene sequencing; Gut microbiota; GIT morphology.