From Maternal Grazing to Barn Feeding During Pre-weaning Period: Altered Gastrointestinal Microbiota Contributes to Change the Development and Function of the Rumen and Intestine of Yak Calves

Abstract

Understanding the altered gastrointestinal microbiota is important to illuminate effects of maternal grazing (MG: maternally nursed and grazed) and barn feeding (BF: supplied milk replacer, starter feed, and alfalfa hay) on the performance and immune function of yak calves. Compared with the MG group, the significantly increased body weight, body height, body length, chest girth, and organ development of liver, spleen, and thymus were identified in the BF group, which were resulted from the significantly increased dry matter intake, increased concentrations of propionate, butyrate, isobutyrate, and valerate, increased ruminal pectinase, duodenal α-amylase, jejunal α-amylase and trypsin, and ileal trypsin, and promoted gastrointestinal epithelial development. Furthermore, genera of Sharpea, Sphingomonas, Atopobium, Syntrophococcus, Clostridium_XIVb, Acinetobacter, Oscillibacter, Dialister, Desulfovibrio, Bacteroides, Lachnospiracea_incertae_sedis, and Clostridium_sensu_stricto, which were involved in utilization of non-fibrous carbohydrate and further beneficial to improve the gastrointestinal digestion, development, and immune functions, were significantly increased in the BF group. Meanwhile, the significantly enhanced ruminal epithelial immune functions and intestinal immune functions based on enhanced ruminal immune related pathway, duodenal IL-1β, jejunal IL-1β, IL-2, TNF-α, and IFN-γ, and ileal IL-1β were identified in the BF group, which also may induced by the increased abundance of gastrointestinal microbiota. Overall, barn feeding significantly increased the diversity of species and abundance of microbes which used different carbohydrates and further benefit to the growth and immune function of yak calves.

Altitude influences microbial diversity and herbage fermentation in the rumen of yaks

“…In addition to variations of yak rumen microbiomes, VFAs exhibited remarkable fluctuations in response to altitude. VFAs are produced by rumen microorganisms fermenting plant cellulose and other carbohydrates, and play an essential role in ruminant growth and immunity [ 47 ]. VFAs formed in the rumen are largely absorbed across the host’s ruminal epithelium [ 9 , 48 ].…”

Mucosal Microbiota and Metabolome in the Ileum of Hu Sheep Offered a Low-Grain, Pelleted or Non-pelleted High-Grain Diet

“…Our results revealed that the relative abundance of the genus Sphingomonas , and several species (e.g., OTU587, OTU487, and OTU433) significantly declined in the ileal mucosal microbiota of the HG group compared with the CON group. Sphingomonas is a strictly aerobic commensal bacteria of the human and animal intestines, and existing evidence from studies suggests that Sphingomonas contributes to the degradation of several types of polysaccharides, such as cellulose ( Birkholz and Kronenberg, 2015 ; Cui et al, 2020 ). Moreover, Sphingomonas spp.…”

Comparing the Bacterial Community in the Gastrointestinal Tracts Between Growth-Retarded and Normal Yaks on the Qinghai–Tibetan Plateau

“…The microbial community in the GIT of mammalian animals has been increasingly identified as an important factor in animals' growth, health, and production performance (Holmes et al, 2012;Yeoman and White, 2014). The microflora in the GIT is an intricate micro-ecosystem, which mainly composes of ciliate protozoa, anaerobic fungi, archaea, and bacteria (Falony et al, 2016;Cui et al, 2020a). A previous study has found that the microbiota acted as an essential role in regulating homeostasis and nutritional metabolism of the host's GIT (Rey et al, 2013).…”