The dynamic changes of rumen bacterial and fungal microbiota in free-ranged Gangba plateau sheep

Abstract Gangba sheep is an important sheep breed in Xizang plateau; however, little information is available about its rumen microbiota. This study revealed the composition and characteristics of rumen bacterial and fungal microbiota in free-ranged Gangba sheep. For bacterial and fungal microbiota sequencing, rumen fluid samples were collected from free-ranged Gangba sheep from four age groups (6, 18, 30, and 42 months; n = 6 each). There were 2 421 684 and 2 463 063 filtered bacterial and fungal reads (bp), respectively in Gangba sheep. No significant differences were observed in the bacterial and fungal alpha diversity indices among Gangba sheep across different age groups. The predominant bacterial phyla were Bacteroidota and Firmicutes A , while Ascomycota and Basidiomycota were the dominant fungal phyla across all age groups of Gangba sheep. A total of seven bacterial phyla and thirty-nine genera, including UBA1711, Treponema D , CAG 41, CAJPSE01, Ruminococcus D , and Denitrobacterium exhibited significant age-related differences in Gangba sheep. Additionally, five fungal genera, Paraphaeosphaeria , Trichocladium , Dictyosporiaceae gen. incertae sedis , Entyloma , and Coprinopsis , showed marked variation among different age groups. Our study provides novel insights into the rumen microbiota, highlighting age related variations influencing microbial ecology. The functional roles and environmental interactions of these microbes may be explored in future studies to enhance sheep health and productivity in plateau regions.