Introduction: Amidst the challenging environmental conditions characterized by low oxygen levels and cold temperatures on the plateau, alterations in nutrient supply emerge as pivotal factors influencing the survival and reproduction of yaks. Intensive feeding stands out as a substantial mechanism for nutrient provision, initiating discernible changes in the host’s rumen flora. Within the extreme natural conditions prevailing in the plateau area of northwest Yunnan, China, there exists a con-strained comprehension of the variations in rumen microflora, fermentation parameters, and growth responses exhibited by yaks subjected to intensive feeding.Methods: This study employs 16S rRNA and ITS sequencing methods to scrutinize the rumen flora of yaks engaged in both natural grazing (G) and intensive feeding (F) on the plateau.Results: The outcomes unveil that, during the severe winter season, yaks adeptly modulate the abundance and diversity of rumen flora in response to dietary modifications under intensive feeding, aiming to optimize the efficient utilization of dietary fiber and energy. Principal Coordinate Analysis (PCoA) illustrates a substantial alteration in the rumen microbial community of naturally grazing yaks when exposed to intensive feeding. The natural grazing group manifests a higher prevalence of Firmicutes and Bacteroidetes, while the intensive feeding group exhibits heightened levels of Prevotella in the rumen. The Rikenellaceae _ RC9 _ gut_ group, associated with mycobacteria, prevails more abundantly in the natural grazing setting. PICRUSt2 analysis indicates that intensive feeding induces bacterial gene overexpression linked to protein metabolism. Rumen fungi showcase heightened diversity under intensification. Intensive feeding results in an augmented abundance of non-fiber-degrading bacteria and semi-fiber-degrading bacteria, accompanied by elevated concentrations of Volatile Fatty Acids (VFA).Discussion: These findings yield novel insights into the shifts in the rumen microflora of yaks acclimated to intensive feeding in high-altitude environments, provide an important reference for the nutritional regulation of supplemental feeding of natural grazing yaks in the cold season, ultimately contributing to their enhanced growth.

The environment is one of the most important factors influencing the variation and diversity of the host gut microbiome in plateau areas. It is well-established that dietary variations substantially alter the rumen microbiota. However, there is limited research on the response of the rumen microbiota of grazing yaks to changes in seasonal diet composition under high-altitude environments. This study investigates the seasonal variations in rumen fermentation parameters, bacterial, and fungal communities in yaks, with a focus on the cold and warm seasons. Quantitative data revealed that in the cold season, yaks had an increased acetic acid proportion (p < 0.05) and acetic acid/propionic acid ratio (p < 0.05) compared to the warm season. The relative abundance of Bacteroidetes and Firmicutes were 64.67% and 25.82% in the cold season, respectively, and 66.77% and 26.87% in the warm season. The fungal community showed a higher abundance of Ascomycetes (58.72% to 76.91%) and Neocallimastigomycota in the cold season. These findings highlight the adaptation mechanisms of yaks to seasonal dietary changes and their implications for optimizing yak husbandry practices.

Enterocytozoon bieneusi is a fungus-like protist parasite that can cause diarrhea and enteric diseases. The infection of E. bieneusi has been reported in many host species, including cattle and humans. However, information on prevalence and genotype distribution of E. bieneusi in dairy cattle in Yunnan province in China is still absent. In this study, 490 Holstein Cows and 351 dairy buffalo fecal samples were collected from three regions in Yunnan province, China. By using nest-PCR that targets the internal transcribed spacer (ITS), we found that the prevalence of E. bieneusi was 0.59% (5/841). DNA sequence analysis showed that five E. bieneusi genotypes were identified in this study, including two novel genotypes, YNDCEB-90 and YNDCEB-174, and three known genotypes (I, J, BEB4). Phylogenetic analysis revealed that two novel genotypes, YNDCEB-90 and YNDCEB-174, were clustered into Group 1, representing the zoonotic potential. The remaining genotypes I, J, and BEB4, which are the most frequent genotypes of E. bieneusi infection in cattle and lead to E. bieneusi infection in humans, belonged to Group 2. Although the lower prevalence of E. bieneusi was detected in dairy cattle in Yunnan province, it indicates that dairy cattle should be considered to be one of the potential hosts for transmitting E. bieneusi to humans. These findings are important for the development of effective prevention strategies for microsporidiosis.

Cyclospora spp. is a food-borne intestinal protozoan, which is widely distributed in the world and poses the risk of zoonosis. In order to reveal the prevalence of Cyclospora spp. in Holstein cattle in partial areas of the Yunnan Province, 524 fresh fecal samples of Holstein cattle were collected from Dali, Kunming, Chuxiong, and Qujing in Yunnan Province. A nested PCR amplification of the small subunit (SSU) rRNA gene of Cyclospora spp. was carried out, and the products of the nested PCR were further analyzed by restriction fragment length polymorphism (RFLP) using Bsp E Ⅰ. The results of the present study showed that 13 samples were positive for Cyclospora spp., and the total infection rate of Cyclospora sp. was 2.48%. The infection of Cyclospora spp. was detected in Dali, Qujing, and Chuxiong. Chuxiong showed the highest infection rate (5.71%), and infection rate in Dali and Qujing was 2.19% and 3.16%, respectively. Interestingly, the infection of Cyclospora spp. was not detected in Kunming. The infection of Cyclospora spp. showed no significant differences among different regions (p > 0.05). Cyclospora sp. infection was detected in all ages and sexes, but the differences were not significant (p > 0.05). Sequencing and phylogenetic analysis showed that five Cyclospora spp. samples were closely related to the Cyclospora spp. of humans, and the others were closely related to the Cyclospora spp. of bovines. The results of the present study suggested that there was an infection of Cyclospora spp. in Holstein cattle in the Yunnan Province, and the Cyclospora spp. showed a risk of zoonosis. Thus, the prevention and control of Cyclospora spp. should be strengthened in the Yunnan Province, China. The results of this investigation provide data references for the further research of Cyclosporiasis in Holstein cattle in the Yunnan Province.

Diannan small-ear pig (DSP) ham is known for exceptional flavor. However, the composition of flavor components and the mechanisms underlying flavor development remain unclear. In this study, we employed lipidomics, flavoromics, and ultra-high-performance liquid chromatography–tandem mass spectrometry technologies to investigate the composition and formation mechanism of DSP ham flavor compounds. On a 10-point scale, the results demonstrated that DSP ham had good flavor qualities with sensory scores of 8.6 ± 0.52 for flavor, 7.9 ± 0.57 for taste, 8.2 ± 0.79 for texture, 8.8 ± 0.42 for color, and 8.3 ± 0.48 for acceptability. A total of 1534 lipids, 80 volatile flavor compounds, and 25 free amino acids were identified in the ham, including 14 characteristic lipids and 28 characteristic flavor compounds. Triglycerides (TG) and diacylglycerol (DG), two important lipids, are broken down into free fatty acids, which are essential building blocks for flavor formation. Non-volatile sweet amino acid L-alanine and bitter amino acid L-lysine are combined with volatile components, including 1-octene-3-ol, hexanal, benzaldehyde, and octanal, to enhance the development of DSP ham flavor. Correlation analysis indicated that key lipids, including TG, DG, and phosphatidylcholines (PC), facilitate the formation of volatile compounds in DSP ham via the glycerophospholipid metabolic pathway. This study provides a theoretical reference for further research and product development of high-quality DSP ham.

The rumen microbiome plays a central role in ruminant nutrition and health. To investigate the effects of different feeding regimens on it, this study employed multi-omics analysis to reveal how natural grazing versus intensive feeding alters the rumen microbiota and metabolites in Shorthorn cattle. A total of 18 male shorthorn cattle of about 17 months of age and similar body weight were selected and randomly divided into 3 groups: natural grazing bull group (DJCF), intensive feeding bull group (DJCY) and intensive feeding steer group (DJC). The experiment period was 361 days. After the fattening trial, rumen fluid was collected at slaughter. Microbiota and metabolites were analyzed by 16S rRNA sequencing and LC–MS, and correlations were assessed. The results indicate that different feeding regimens were strongly associated with shifts in rumen microbial diversity and community composition. The ACE and Shannon indices of DJCF group were significantly higher than those of DJCY and DJC group ( p < 0.05). Bacteroidetes and Firmicutes were the dominant phyla, with relative abundances of 57.62% (DJCF), 54.11% (DJCY), 48.84% (DJC) and 34.07, 38.31, 43.08%, respectively, showing no significant differences ( p > 0.05). At the genus level, Prevotella and Rikenellaceae_RC9_gut_group were dominant. The abundance of Prevotella was highest in DJCY (22.52%), significantly differing from DJC (12.43%; p < 0.05), while Rikenellaceae_RC9_gut_group abundances were 12.56% (DJCF), 9.92% (DJCY), and 11.89% (DJC). In the fungal community, Neocallimastigomycota and Ascomycota were the dominant phyla, and there were no significant differences among the three groups. At the genus level, Caecomyces , the highest in the DJC group, with a significant difference from the DJCF group ( p < 0.05). Orpinomyces , the highest in the DJCF group, with significant differences from the DJCY and DJC groups ( p < 0.05). There were significant differences in rumen metabolites between different groups, and a variety of different metabolites were identified, involving sucrose and starch metabolism, purine metabolism and other pathways ( p < 0.05). In addition, there was a significant correlation between rumen microbes and metabolites ( p < 0.05). Thus, an intensive feeding system altered the rumen microbiome, resulting in improvements of Shorthorn cattle growth. Nevertheless, the specific causal relationships and underlying regulatory mechanisms governing the interplay between rumen microbiota and metabolic processes remain to be further elucidated through in-depth investigations.