Comparison and Characterization of intestinal microbiota dy-namics in post-weaning yak and cattle calves grazing on alpine rangeland

The gastrointestinal microbiota plays an important role in animal health and production. However, little information is available on the dynamic characterization and comparison of gut microbiota in weaned yaks (Bos grunniens) and cattle (Bos taurus) calves living on the Qinghai-Tibetan Plateau. Here, we explored the fecal microbiota succession of yak and cattle calves at different periods after weaning by using 16S rDNA sequencing. We found that the core fecal microbiota from the two kinds of calves was dominated by Ruminococcaceae, Rikenellaceae, Bacteroidaceae, and Lachnospiraceae. Additionally, we found that there were differences in the fecal microbiota structure and characteristics between yak and cattle calves at the first month after weaning, but the microbial profile tended to be consistent as they grew up. Similarly, the fecal microbial function of the calves in the first month was significantly different in enzyme families, nervous system, and circulatory system, while the intestinal microbial function at other time points was similar. Therefore, based on the dynamic changes of the intestinal microbiota at the early stage of life, it is helpful to make rational strategies to manipulate the intestinal microbiota, thereby improving the growth and health of grazing ruminants throughout the entire conventional production processes in the region of the Qinghai-Tibetan Plateau.