Exploring the temporal dynamics of rumen bacterial and fungal communities in yaks (Bos grunniens) from 5 days after birth to adulthood by full-length 16S and 18S rRNA sequencing

Abstract

The rumen of ruminants is inhabited by complex and diverse microorganisms. Young animals are exposed to a variety of microorganisms from their mother and the environment, and a few colonize and survive in their digestive tracts, forming specific microflora as the young animals grow and develop. In this study, we conducted full-length sequencing of bacterial and fungal communities in the rumen of pastured yaks of different ages (from 5 days after birth to adulthood) using amplified sequencing technology. The results showed that the rumen microflora of Zhongdian yaks changed gradually from 5 to 180 days after birth and tended to stabilize at 2 years of age. The rumen of adult yaks was the most suitable for the growth and reproduction of most bacteria. Bactria diversity of the yak rumen increased gradually from 5 days after birth to adulthood. With the growth of yaks, different dominated bacteria were enriched in different groups, but Prevotella remained highly abundant in all groups. The yak rumen at 90 days of age was the most suitable for the growth and reproduction of most fungi, and 90 days of age could be a cut-off point for the distribution of fungal communities. Fungal Thelebolus was the firstly reported in yak rumen and was enriched in the yak rumen of 90 days after birth. The most abundant and balanced fungal genera were found in adult yaks, and most of them were only detected in adult yaks. Our study reported on the rumen bacterial and fungal communities of Zhongdian yaks grazed at different ages and provided insights into the dynamic changes of dominant microflora with yak growth.

Microbial Metagenomes and Host Transcriptomes Reveal the Dynamic Changes of Rumen Gene Expression, Microbial Colonization and Co-Regulation of Mineral Element Metabolism in Yaks from Birth to Adulthood

“…However, one study used 16S and 18S rRNA to sequence rumen microorganisms of yaks aged from 7 days to 12 years, and found that archaea were detected only after 14 days of age [19], which was inconsistent with this study, possibly due to different detection methods. We also found that the dominant phyla were Bacteroidetes and Firmicutes across all ages, which is in accordance with other recent studies on yaks [63]. In the 1 d and 20 d groups, the bacterial phylum Proteobacteria was significantly more numerous than that in other ages, which was consistent with previous studies that facultative anaerobic Proteobacteria are more adapted to the liquid-based dietary stage of early life [64,65].…”

“…Rumen microbial community composition changed with the developmental stage [17,62]. However, the microbial population dynamics from newborn to adult yaks are poorly understood, as only a few studies have been reported on ruminal bacterial community in yaks from birth (5 days or 7 days after birth) to adulthood (2 years or 12 years) using 16S and 18S rRNA sequencing [19,63]. In the present study, metagenomics analysis was used to evaluate the composition and temporal dynamics of rumen microorganisms, from birth to adult, of Maiwa yak.…”

Effects of yeast culture on in vitro ruminal fermentation and microbial community of high concentrate diet in sheep

“…In addition to bacterial community, the fungi are also important components of ruminal microorganism. Ruminal fungus can fully degrade plant fiber, because it can penetrate and break the plant cell wall tissue as well as secreting a variety of cellulose degrading enzymes (Yang et al 2023 ). Hence, the ruminal fungus can decompose some lignified fibrous materials which cannot be utilized by cellulose-degrading bacteria.…”

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

“…Yak rumen microorganisms alter accordingly to cope with changing diets at different growth stages, with greater relative abundances of Ascomycetes and Mesomycetes, that is, fungi adapted to liquid rations during juvenile years [ 13 , 14 ]. 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 ].…”