Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Jun 29:9:922817.
doi: 10.3389/fvets.2022.922817. eCollection 2022.

The Response of Ruminal Microbiota and Metabolites to Different Dietary Protein Levels in Tibetan Sheep on the Qinghai-Tibetan Plateau

Xungang Wang  1 , Tianwei Xu  1 , Xiaoling Zhang  1   2 , Na Zhao  1 , Linyong Hu  1 , Hongjin Liu  1 , Qian Zhang  1   2 , Yuanyue Geng  1   2 , Shengping Kang  3 , Shixiao Xu  1
Affiliations

The Response of Ruminal Microbiota and Metabolites to Different Dietary Protein Levels in Tibetan Sheep on the Qinghai-Tibetan Plateau

Xungang Wang et al. Front Vet Sci. .

Abstract

Ruminal microbiota and metabolites play crucial roles in animal health and productivity. Exploring the dynamic changes and interactions between microbial community composition and metabolites is important for understanding ruminal nutrition and metabolism. Tibetan sheep (Ovis aries) are an important livestock resource on the Qinghai-Tibetan Plateau (QTP), and the effects of various dietary protein levels on ruminal microbiota and metabolites are still unknown. The aim of this study was to investigate the response of ruminal microbiota and metabolites to different levels of dietary protein in Tibetan sheep. Three diets with different protein levels (low protein 10.1%, medium protein 12.1%, and high protein 14.1%) were fed to Tibetan sheep. 16S rRNA gene sequencing and gas chromatography coupled with time-of-flight mass spectrometry (GC-TOF-MS) were used to study the profile changes in each group of ruminal microbes and metabolites, as well as the potential interaction between them. The rumen microbiota in all groups was dominated by the phyla Bacteroidetes and Firmicutes regardless of the dietary protein level. At the genus level, Prevotella_1, Rikenellaceae_RC9_gut_group and Prevotellaceae_UCG-001 were dominant. Under the same forage-to-concentrate ratio condition, the difference in the dietary protein levels had no significant impact on the bacterial alpha diversity index and relative abundance of the major phyla and genera in Tibetan sheep. Rumen metabolomics analysis revealed that dietary protein levels altered the concentrations of ruminal amino acids, carbohydrates and organic acids, and significantly affected tryptophan metabolism (p < 0.05). Correlation analysis of the microbiota and metabolites revealed positive and negative regulatory mechanisms. Overall, this study provides detailed information on rumen microorganisms and ruminal metabolites under different levels of dietary protein, which could be helpful in subsequent research for regulating animal nutrition and metabolism through nutritional interventions.

Keywords: Tibetan sheep; dietary protein; metabolomics; microbiota; rumen.

PubMed Disclaimer

Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
Bacterial diversity of rumen fluid samples among three different groups. (A) Richness index; (B) Shannon index; (C) CPCoA plot based on ASVs.
Figure 2
Figure 2
Microbial composition of rumen fluid samples at the (A) phylum and (B) genus level.
Figure 3
Figure 3
OPLS-DA of ruminal metabolites between different groups.
Figure 4
Figure 4
Heatmap of differential metabolites in rumen fluid samples between different groups.
Figure 5
Figure 5
KEGG pathways based on the differential metabolites identified in different groups.
Figure 6
Figure 6
Heatmap of Spearman correlations between main genera and differential metabolites. *p < 0.05.
See this image and copyright information in PMC

References

    1. Zhou JW, Guo XS, Degen AA, Zhang Y, Liu H, Mi JD, et al. Urea kinetics and nitrogen balance and requirements for maintenance in Tibetan sheep when fed oat hay. Small Ruminant Res. (2015) 129:60–8. 10.1016/j.smallrumres.2015.05.009 - DOI
    1. Langda S, Zhang C, Zhang K, Gui B, Ji D, Deji C, et al. Diversity and composition of rumen bacteria, fungi, and protozoa in goats and sheep living in the same high-altitude pasture. Animals. (2020) 10:186. 10.3390/ani10020186 - DOI - PMC - PubMed
    1. Yang C, Gao P, Hou F, Yan T, Chang S, Chen X, et al. Relationship between chemical composition of native forage and nutrient digestibility by Tibetan sheep on the Qinghai-Tibetan Plateau. J Anim Sci. (2018) 96:1140–9. 10.1093/jas/sky002 - DOI - PMC - PubMed
    1. Long RJ, Apori SO, Castro FB, Ørskov ER. Feed value of native forages of the Tibetan Plateau of China. Anim Feed Sci Technol. (1999) 80:101–13. 10.1016/S0377-8401(99)00057-7 - DOI
    1. Zhao X, Zhou X. Ecological basis of alpine meadow ecosystem management in Tibet: Haibei alpine meadow ecosystem research station. Ambio. (1999) 28:642–7.