Changes in the environment such as high-altitude hypoxia (HAH) high-altitude hypoxia can lead to adaptive changes in the blood system of mammals. However, there is limited information about the adaptation of Holstein dairy cows introduced to high-altitude areas. This study used 12 multiparous Holstein dairy cows (600 ± 55 kg, average three years old) exposed to HAH conditions in Nyingchi of Tibet (altitude 3000 m) and HAH-free conditions in Shenyang (altitude 50 m). The miRNA microarray analysis and iTRAQ proteomics approach (accepted as more suitable for accurate and comprehensive prediction of miRNA targets) were applied to explore the differences in the plasma proteomic and miRNA profiles in Holstein dairy cows. A total of 70 differential miRNAs (54 up-regulated, Fold change (FC) FC > 2, and 16 down-regulated, FC < 0.5) and 226 differential proteins (132 up-regulated, FC > 1.2, and 94 down-regulated, FC < 0.8) were found in the HAH-stressed group compared with the HAH-free group. Integrative analysis of proteomic and miRNA profiles demonstrated the biological processes associated with differential proteins were the immune response, complement activation, protein activation, and lipid transport. The integrative analysis of canonical pathways were most prominently associated with the APR signaling (z = 1.604), and LXR/RXR activation (z = 0.365), and FXR/RXR activation (z = 0.446) pathways. The current results indicated that Holstein dairy cows exposed to HAH could adapt to high-altitude hypoxia by up-regulating the APR, activating the LXR/RXR and FXE/RXR pathways.

Studies associated with regional roughage utilisation in Tibetan sheep have been limited. This study focussed on the mechanism of lipid metabolism and deposition in Tibetan sheep fed local roughage sources. Twenty-four Tibetan sheep weighing 16.1 ± 1.76 kg were randomly assigned to two mixed diets containing the same concentrate mixed with oat grass (OG) or highland barley straw (HBS). The ME and CP of OG diet were 7.16 MJ/kg DM and 5.94%, respectively, while in HBS diet were 7.13 MJ/kg DM and 7.39%. Lipid profiles in the plasma and liver, fatty acid (FA) composition and lipogenetic genes expression in the muscle and adipose tissue were determined. No difference was observed in DMI, total cholesterol, triglyceride, low-density lipoprotein and high-density lipoprotein levels in the plasma and liver of sheep between two groups (p>.05). Plasma leptin and liver non-esterified fatty acid (NEFA) content in HBS group tended to be greater than that in OG group (p < .01). Sheep in HBS group had greater C18:2, C20:4, PUFA and PUFA/SFA ratio in the longissimus dorsi muscle (p < .05) and lower C17:0 (p ¼ .05) and C20:1 (p < .01) in the perirenal adipose fat. Perirenal C18:0, C20:3 and C20:4 contents in HBS group tended to increase (p < .01). HBS stimulated the mRNA expression of SCD, C/EBPc and SREBF1 in the muscle and FASN in the perirenal adipose fat (p < .01), but inhibited HSL, LPL, C/EBPc and PPARc expression in the perirenal adipose fat. These results indicated that replacement of OG by HBS promotes PUFA deposition in the muscle and long-chain FAs in the adipose fat of Tibetan sheep. Lipid deposition-related genes (SCD, FASN, HSL and LPL) and lipid metabolism regulators (C/EBPc, SREBF1 and PPARc) are involved in the transcriptional regulation.

The majority of native cattle are taurine × indicine cattle of diverse phenotypes in the central region of China. Sanjiang cattle, a typical breed in the central region, play a central role in human livelihood and have good adaptability, including resistance to dampness, heat, roughage, and disease, and are thus regarded as an important genetic resource. However, the genetic history of the successful breed remains unknown. Here, we sequenced 10 Sanjiang cattle genomes and compared them to the 70 genomes of 5 representative populations worldwide. We characterized the genomic diversity and breed formation process of Sanjiang cattle and found that Sanjiang cattle have a mixed ancestry of indicine (55.6%) and taurine (33.2%) dating to approximately 30 generations ago, which has shaped the genome of Sanjiang cattle. Through ancestral fragment inference, selective sweep and transcriptomic analysis, we identified several genes linked to lipid metabolism, immune regulation, and stress reactions across the mosaic genome of Sanjiang cattle showing an excess of taurine or indicine ancestry. Taurine ancestry might contribute to meat quality, and indicine ancestry is more conducive to adaptation to hot climate conditions, making Sanjiang cattle a valuable genetic resource for the central region of China. Our results will help us understand the evolutionary history and ancestry components of Sanjiang cattle, which will provide a reference for resource conservation and selective breeding of Chinese native cattle.

Background: Grazing and house feeding methods have been studied on yak, but there is no relevant research on grazing and indoor feeding of Jersey cattle on the Qinghai-Tibet Plateau.Results: In this study, the differences in metabolites in the serum and rumen of Tibet Plateau Jersey cattle in total mixed ration house feeding and grazing supplementary feeding were assessed. The rumen fermentation parameters, bacterial community, serum antioxidant indices, immune indices and metabolites of total mixed rations house-feeding Jersey cattle (Group B, n =6) and grazing supplementary-feeding Jersey cattle (Group G, n =6) were evaluated. The rumen fermentation parameters results showed that the acetic acid and propionic acid concentrations and the ammonia nitrogen concentration in Group B were significantly higher than those in Group G (P < 0.05). The rumen bacterial community 16S rDNA gene results showed that The Chao1 index was significantly higher in Group G than in Group B (P < 0.05), and the observed_species, Shannon and Simpson indices were not significantly different between the two groups (P > 0.05). The distance between the two groups by principal component analysis was not significant, and adnoism analysis showed that there was no significant difference in rumen flora between Group G and Group B (R=0.55, P=0.08). Antioxidant and immune indices analysis of serum results showed that there was no significant difference in total antioxidant capacity between Group G and Group B (P > 0.05), while IL-6, Ig-M and TNF-α were significantly higher in Group G than in Group B (P < 0.05). LC‒MS metabolomics analysis of serum results showed that, A total of 149 major serum differential metabolites were identified between Group G and Group B. The differential metabolites were mainly enriched in the metabolic pathways of biosynthesis of amino acids, protein digestion and absorption, ABC transporters, aminoacyl-tRNA biosynthesis, mineral absorption and biosynthesis of unsaturated fatty acids and other metabolic pathways.Conclusions: The results of this study revealed the differences in rumen fermentation and serum metabolism of Jersey cattle under different feeding methods, providing a theoretical basis for the scientific feeding of Tibetan Plateau Jersey cattle.