Search

Simple Summary: Characterization of the microbiota in livestock animals is of great interest for improving reproductive performances. Shifts in vaginal and uterine microbiota are well-studied, but the intestinal microbiota in ruminants during estrus is largely unknown. The intestinal microbiota of grazing Simmental cows undergoing estrus synchronization was studied in this work. The structure, composition, and function of the intestinal microbiota shifted during this process, and these shifts were mediated by reproductive hormones. To study shifts in the intestinal microbiota during estrus synchronization in ruminants, we characterized the intestinal microbiota in grazing Simmental cows and the possible mechanism that mediates this shift. Fourteen postpartum Simmental beef cows were synchronized beginning on day 0 (D0) with a controlled internal release device (CIDR), and cloprostenol was injected on D9 when the CIDR was withdrawn. Synchronization ended with timed artificial insemination on D12. Serum and rectal samples harvested on D0, D9, and D12 were analyzed to assess the reproductive hormones and microbiota. Reproductive hormones in the serum of the host were measured using enzyme-linked immunosorbent assay. The microbiota was characterized using 16S rRNA sequencing of the V3–V4 hypervariable region, alpha diversity and beta diversity analyses (principal coordinate analysis, PCoA), cladogram of the linear discriminant analysis effect size (LEfSe) analysis, and microbiota function analysis. Levels of the reproductive hormones, except gonadotropin-releasing hormone (p > 0.05), shifted among D0, D9, and D12 (p < 0.05). Decreased community diversity (Chao1 and ACE) was observed on D12 compared with D0 (p < 0.05). The beta diversity (PCoA) of the microbiota shifted markedly among D0, D9, and D12 (p < 0.05). The LEfSe analysis revealed shifts in the intestinal microbiota communities among D0, D9, and D12 (p < 0.05 and LDA cutoff >3.0). The KEGG pathway analysis showed that carbohydrate metabolism, genetic information and processing, the excretory system, cellular processes and signaling, immune system diseases, and the metabolism were altered (p < 0.05). Reproductive hormones (especially estradiol) were correlated with the alpha diversity indices, beta diversity indices, and an abundance of biomarkers of the shifting intestinal microbiota (p < 0.05). In conclusion, the structure, composition, and function of the intestinal microbiota were shifted during estrus synchronization in a grazing Simmental cow model, and these shifts were mediated by reproductive hormones. [ABSTRACT FROM AUTHOR]

Simple Summary: The increase in the metabolic demand and the dramatically decreased feed intake of cows around parturition often cause a negative energy balance status in cows, which can cause metabolic disorders. Before parturition, dry matter intake of cows starts to decline, and this decline is practically unavoidable. Therefore, increasing the energy density of the diet is extremely important. We used untargeted metabolomics to reveal the effect of high dietary energy density on body metabolism and explore whether it can alleviate negative energy balance. Our research shows that feeding a high-energy diet could significantly improve antioxidant capacity, maintain phosphatidylcholine homeostasis and reduce the negative energy balance of cows by regulating lipid mobilization, muscle mobilization, and protein turnover. The diet energy level plays a vital role in the energy balance of transition cows. We investigated the effects of high dietary energy density on body metabolism. Twenty multiparous Angus cows were randomly assigned to two treatment groups (10 cows/treatment), one receiving a high-energy (HE) diet (NEm = 1.67 Mcal/kg of DM) and the other administered a control (CON) diet (NEm = 1.53 Mcal/kg of DM). The results indicated that feeding a high-energy diet resulted in higher plasma glucose concentration and lower concentrations of plasma NEFA and BHBA on d 14 relative to calving in the HE-fed cows compared to the CON-fed ones. The postpartum plasma levels of T-AOC were lower in cows that received the CON diet than in cows in the HE group, while the concentration of malondialdehyde (MDA) showed an opposite trend. Among the 51 significantly different metabolites, the concentrations of most identified fatty acids decreased in HE cows. The concentrations of inosine, glutamine, and citric acid were higher in HE-fed cows than in CON-fed cows. Enrichment analysis revealed that linoleic acid metabolism, valine, leucine as well as isoleucine biosynthesis, and glycerophospholipid metabolism were significantly enriched in the two groups. [ABSTRACT FROM AUTHOR]

These results indicate that the microbial diversity of calves increased with age, but diarrhea induced by pathogenic I E. coli i O1 reduced the richness and diversity of the rectal microbial flora of the calves. The study of the influence of pathogenic I E. coli i on the composition and function of calf intestinal florae and the content of SCFAs in feces may provide theoretical reference for the prevention and treatment of calf diarrhea. This indicates that calf diarrhea caused by pathogenic I E. coli i infection affects the digestion and absorption of nutrients in the body, but as calves grow, the body's demand for nutrients and energy increases, and the abundance of Firmicutes increases. At the beginning of the experiment, the calves of the TG were orally administered pathogenic I E. coli i O1 (2.5 × 10 SP 11 sp colony-forming unit (CFU)/mL, 100 mL) to establish a calf diarrhea model, and the NG was orally administered the same amount of physiological saline solution. [Extracted from the article]

Simple Summary: Calf diarrhea is a major cause of mortality in calves, and results in high treatment costs and economic loss for the dairy and cattle industries. In addition, diarrhea usually occurs around 2 weeks after calf birth. In this study, we determined how compound probiotics influenced the gut microbiota and its effect on diarrhea rates of newborn Holstein calves. The probiotics included compound yeast (Saccharomyces cerevisiae and Kluyveromyces marxianus) and lactic acid bacteria (Lactococcus lactis subsp. lactis, Pediococcus pentosaceus, and Lactobacillus plantarum). Among them, the LS, L, and S groups are different compound probiotic groups, and the D group is the control group. Our results revealed that although probiotics did not affect the community diversity of gut bacteria in newborn calves, compound probiotics significantly increased the community richness of gut bacteria. Principal coordinates analysis using weighted UniFrac distances showed that the microbial communities of calves fed compound probiotics were relatively closely clustered, but were separate from the communities of calves in the control group. The calves fed compound probiotics also had lower rates of diarrhea. Our findings improve our understanding of the role of probiotics in regulating the gut microbiota of calves, and are of special significance to researchers in the dairy and cattle industries. We evaluated the effects of probiotic compounds on the composition of the gut microbiota. Forty newborn calves were random allocated to the lactic acid bacteria + yeast group (LS group), lactic acid bacteria group (L group), yeast group (S group), and control group (D group). Probiotics containing Lactococcus lactis subsp. lactis, Pediococcus pentosaceus, Lactobacillus plantarum, Saccharomyces cerevisiae, and Kluyveromyces marxianus were fed to calves in the three treatment groups for 15 days. The feeding process lasted 15 days. Fecal samples were collected from all calves at the end of the trial and analyzed using high-throughput 16S rRNA sequencing. Totals of 1,029,260 high-quality reads and 420,010,128 bp of sequences were obtained. Among the four groups, the alpha diversity of gut microbes was significantly higher in newborn cattle in the LS group than in those in the L, S, and D groups. Overall, the dominant phyla were Firmicutes, Actinobacteria, and Bacteroidetes, whereas Bifidobacterium was the most abundant phylum in the gut of cattle in the LS group. Newborn calves from the compound probiotic groups had closely clustered gut bacterial communities and had lower rates of diarrhea. Overall, compound probiotics regulated the intestinal microbiota community structure of newborn calves and improved intestinal health. New information relevant to the prevention of diarrhea is provided by our research in newborn calves. [ABSTRACT FROM AUTHOR]

Simple Summary: Diarrhea is associated with intestinal inflammation and ecological imbalance of the intestinal flora. Emodin is an herbal ingredient with various pharmacological effects, such as antibacterial, anti-inflammatory, and anti-cancer. Although several characteristics of emodin have been reported, the effects of orally administered emodin on the structure of the intestinal microbial community and immunological parameters in mice with enterotoxigenic Escherichia coli (ETEC) infection are not well understood. Therefore, this study focused on determining whether emodin mitigates the negative effects of ETEC infection on intestinal barrier function and immune response in mice by altering intestinal flora. The results suggest that emodin protects against intestinal damage induced by E. coli O1 and improves intestinal mucosal barrier function in mice by increasing the abundance of beneficial intestinal microbiota and inhibiting the abundance of harmful bacteria, thereby alleviating diarrhea. The findings of this study will contribute to our understanding of how emodin attenuates the effects of ETEC on intestinal mucosal barrier damage by modulating the microbial composition of the gut. The effect of emodin on the intestinal mucosal barrier of a mouse E. coli O1-induced diarrhea model was observed. Following successful establishment of a diarrhea model, the mice were treated with drugs for seven days. Intestinal lesions and the shape and the number of goblet cells were assessed via hematoxylin-eosin and periodic-acid-Schiff staining, while changes in inflammatory factors, ultrastructure of the small intestine, expression of MUC-2, and changes in the intestinal microbiota were analyzed via RT-PCR, electron microscopy, immunofluorescence, and 16S rRNA sequencing. Examination showed that emodin ameliorated pathological damage to the intestines of diarrheic mice. RT-PCR indicated that emodin reduced TNF-α, IL-β, IL-6, MPO, and COX-2 mRNA levels in duodenal tissues and increased the levels of sIgA and MUC-2 and the number of goblet cells. Microbiome analysis revealed that Escherichia coli O1 reduced bacterial richness and altered the distribution pattern of bacterial communities at the phylum and order levels in cecum contents. Notably, pathogenic Clostridiales and Enterobacteriales were significantly increased in diarrheic mice. However, emodin reversed the trend. Thus, emodin protected against intestinal damage induced by E. coli O1 and improved intestinal mucosal barrier function in mice by increasing the abundance of beneficial intestinal microbiota and inhibiting the abundance of harmful bacteria, thereby alleviating diarrhea. [ABSTRACT FROM AUTHOR]

Simple Summary: Recently, there has been increasing attention focused on the intestinal microflorae of animals due to their critical role in maintaining health and preventing disease. With the improvement of the Chinese national economy and the people's material standard of living, the beef cattle industry is growing rapidly to meet the growing market demand for beef. Mongolian cattle is a precious genetic resource in China and an excellent cattle breed in Inner Mongolia. However, updated research on topics concerning the gut microbiota of Mongolian cattle are absent. Therefore, this study focused on the differences in the gut microbiota composition of Mongolian cattle in different geographical environments. The gut microbiota composition of the Mongolian cattle from the grasslands was relatively similar, while that from the desert areas was different. The results of this study contribute to our understanding of the influence of geographical factors on the composition of gut microbiota in Mongolian cattle. Mongolian cattle from China have strong adaptability and disease resistance. We aimed to compare the gut microbiota community structure and diversity in grazing Mongolian cattle from different regions in Inner Mongolia and to elucidate the influence of geographical factors on the intestinal microbial community structure. We used high throughput 16S rRNA sequencing to analyze the fecal microbial community and diversity in samples from 60 grazing Mongolian cattle from Hulunbuir Grassland, Xilingol Grassland, and Alxa Desert. A total of 2,720,545 high-quality reads and sequences that were 1,117,505,301 bp long were obtained. Alpha diversity among the three groups showed that the gut microbial diversity in Mongolian cattle in the grasslands was significantly higher than that in the desert. The dominant phyla were Firmicutes and Bacteroidetes, whereas Verrucomicrobia presented the highest abundance in the gut of cattle in the Alxa Desert. The gut bacterial communities in cattle from the grasslands versus the Alxa Desert were distinctive, and those from the grasslands were closely clustered. Community composition analysis revealed significant differences in species diversity and richness. Overall, the composition of the gut microbiota in Mongolian cattle is affected by geographical factors. Gut microbiota may play important roles in the geographical adaptations of Mongolian cattle. [ABSTRACT FROM AUTHOR]