Dynamics and stabilization of the rumen microbiome in yearling Tibetan sheep.

The productivity of ruminants depends largely on rumen microbiota. However, there are few studies on the age-related succession of rumen microbial communities in grazing lambs. Here, we conducted 16 s rRNA gene sequencing for bacterial identification on rumen fluid samples from 27 Tibetan lambs at nine developmental stages (days (D) 0, 2, 7, 14, 28, 42, 56, 70, and 360, n = 3). We observed that Bacteroidetes and Proteobacteria populations were significantly changed during the growing lambs' first year of life. Bacteroidetes abundance increased from 18.9% on D0 to 53.9% on D360. On the other hand, Proteobacteria abundance decreased significantly from 40.8% on D0 to 5.9% on D360. Prevotella_1 established an absolute advantage in the rumen after 7 days of age. The co-occurrence network showed that the different microbial of the rumen presented a complex synergistic and cumbersome relationship. A phylogenetic tree was constructed, indicating that during the colonization process, may occur a phenomenon in which bacteria with close kinship are preferentially colonized. Overall, this study provides new insights into the colonization of bacterial communities in lambs that will benefit the development of management strategies to promote colonization of target communities to improve functional development.