AUTHOR=Cui Xiaojing , Liu Yue , Wu Hao , Meng Qingxiang , Liu Shujie , Chai Shatuo , Hao Lizhuang , Zhou Zhenming 

TITLE=Dynamic changes in the yak rumen eukaryotic community and metabolome characteristics in response to feed type

JOURNAL=Frontiers in Veterinary Science

VOLUME=9

YEAR=2022

URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.1027967

DOI=10.3389/fvets.2022.1027967

ISSN=2297-1769

ABSTRACT=<p>With diversification of yak breeding, it is important to understand the effects of feed type on the rumen, especially microbiota and metabolites. Due to the unique characteristics of yak, research on rumen microbes and metabolites is limited. In this study, the effects of two diet types on rumen eukaryotic microflora and metabolites were evaluated using the Illumina MiSeq platform and liquid chromatography-mass spectrometry (LC-MS). All identified protozoa belonged to <italic>Trichostomatia</italic>. At the genus level, the relative abundance of <italic>Metadinium</italic> and <italic>Eudiplodinium</italic> were significantly (<italic>p</italic> &lt; 0.05) higher in the roughage group than that of concentrate group, while the concentrate group harbored more <italic>Isotricha</italic>. <italic>Ascomycota, Basidiomycota</italic>, and <italic>Neocallimastigomycota</italic> were the main fungal phyla, and the <italic>Wallemia, Chordomyces, Chrysosporium, Cladosporium, Scopulariopsis</italic>, and <italic>Acremonium</italic> genera were significantly (<italic>p</italic> &lt; 0.05) more abundant in the roughage group than the concentrate group, while the concentrate group harbored more <italic>Aspergillus, Neocallimastix, Thermoascus</italic>, and <italic>Cystofilobasidium</italic> (<italic>p</italic> &lt; 0.05). Metabolomics analysis showed that feed type significantly affected the metabolites of rumen protein digestion and absorption (L-proline, L-phenylalanine, L-tryosine, L-leucine, L-tryptophan, and β-alanine), purine metabolism (hypoxanthine, xanthine, guanine, guanosine, adenosine, and adenine), and other metabolic pathway. Correlation analysis revealed extensive associations between differential microorganisms and important metabolites. The results provide a basis for comprehensively understanding the effects of feed types on rumen microorganisms and metabolites of yaks. The findings also provide a reference and new directions for future research.</p>