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

Abstract

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 Trichostomatia. At the genus level, the relative abundance of Metadinium and Eudiplodinium were significantly (p < 0.05) higher in the roughage group than that of concentrate group, while the concentrate group harbored more Isotricha. Ascomycota, Basidiomycota, and Neocallimastigomycota were the main fungal phyla, and the Wallemia, Chordomyces, Chrysosporium, Cladosporium, Scopulariopsis, and Acremonium genera were significantly (p < 0.05) more abundant in the roughage group than the concentrate group, while the concentrate group harbored more Aspergillus, Neocallimastix, Thermoascus, and Cystofilobasidium (p < 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.

Rumen protozoa are a hub for diverse hydrogenotrophic functions

“…Henderson et al, which assessed the protozoa community across different cohorts of different species of ruminants, similarly reported a strong host individuality in protozoa communities even within specific cohorts 8 . Furthermore, a recent study in the yak rumen found several differences in the relative abundance of some protozoa species in response to feed type, but overall community structure as measured by Beta diversity was not significantly different as opposed to bacterial or the fungal community 9 . Our results further support the notion of a higher stability of protozoa in the rumen, which was observed by examining the community changes when the animal diet was switched (Figure 1c).…”

Changes in host liver transcriptome and rumen microbiota community in fattening goats fed different type of forages

“…Ruminants and microorganisms are in constant dynamic balance of mutual dependence and restriction, and forage type can change microbes dramatically to adapt it [25]. The gut-liver axis plays crucial roles in nutrition absorption as the liver receives approximately two-thirds of blood from intestine.…”

Yaks Are Dependent on Gut Microbiota for Survival in the Environment of the Qinghai Tibet Plateau

“…The fungal structure changes continually; at the grazing stage, after 90 days of age, there is an increase in the relative abundance of Thelebolus, a genus that contributes to host immunity and by 180 days of age, there is an increase in the relative abundance of Penicillium, a genus with a strong cellulose degrading capacity [15]. In addition, yaks have adapted to the plateau environment by preferentially harboring protozoa such as rumen ciliates that have evolved to digest mainly fibers [16]. Yaks also alter rumen protozoa at 90 days of age as the dietary fiber content increases, with an increase in the abundance of Dasytricha spp, and a decrease in Entodinium [17], while Isotricha spp.…”