RESUMEN
BACKGROUND: Four-chambered stomach including the forestomachs (rumen, reticulum, and omasum) and abomasum allows ruminants convert plant fiber into high-quality animal products. The early development of this four-chambered stomach is crucial for the health and well-being of young ruminants, especially the immune development. However, the dynamics of immune development are poorly understood. RESULTS: We investigated the early gene expression patterns across the four-chambered stomach in Hu sheep, at 5, 10, 15, and 25 days of age. We found that forestomachs share similar gene expression patterns, all four stomachs underwent widespread activation of both innate and adaptive immune responses from d 5 to 25, whereas the metabolic function were significantly downregulated with age. We constructed a cell landscape of the four-chambered stomach using single-cell sequencing. Integrating transcriptomic and single-cell transcriptomic analyses revealed that the immune-associated module hub genes were highly expressed in T cells, monocytes and macrophages, as well as the defense-associated module hub genes were highly expressed in endothelial cells in the four-stomach tissues. Moreover, the non-immune cells such as epithelial cells play key roles in immune maturation. Cell communication analysis predicted that in addition to immune cells, non-immune cells recruit immune cells through macrophage migration inhibitory factor signaling in the forestomachs. CONCLUSIONS: Our results demonstrate that the immune and defense responses of four stomachs are quickly developing with age in lamb's early life. We also identified the gene expression patterns and functional cells associated with immune development. Additionally, we identified some key receptors and signaling involved in immune regulation. These results help to understand the early life immune development at single-cell resolution, which has implications to develop nutritional manipulation and health management strategies based on specific targets including key receptors and signaling pathways.
RESUMEN
BACKGROUND: Diarrhea is a major cause of morbidity and mortality in young calves, resulting in considerable economic loss for dairy farms. To determine if some gut microbes might have resistance to dysbiotic process with calf diarrhea by dictating the microbial co-occurrence patterns from birth to post-weaning, we examined the dynamic development of the gut microbiota and diarrhea status using two animal trials, with the first trial having 14 Holstein dairy calves whose fecal samples were collected 18 times over 78 d from birth to 15 d post-weaning and the second trial having 43 Holstein dairy calves whose fecal samples were collected daily from 8 to 18 days of age corresponding to the first diarrhea peak of trial 1. RESULTS: Metataxonomic analysis of the fecal microbiota showed that the development of gut microbiota had three age periods with birth and weaning as the separatrices. Two diarrhea peaks were observed during the transition of the three age periods. Fusobacteriaceae was identified as a diarrhea-associated taxon both in the early stage and during weaning, and Clostridium_sensu_stricto_1 was another increased genus among diarrheic calves in the early stage. In the neonatal calves, Prevotella_2 (ASV4 and ASV26), Prevotella_9 (ASV43), and Alloprevotella (ASV14) were negatively associated with Clostridium_sensu_stricto_1 (ASV48), the keystone taxa of the diarrhea-phase module. During weaning, unclassified Muribaculaceae (ASV28 and ASV44), UBA1819 (ASV151), Barnesiella (ASV497), and Ruminococcaceae_UCG-005 (ASV254) were identified being associated with non-diarrheic status, and they aggregated in the non-diarrhea module of co-occurrence patterns wherein unclassified Muribaculaceae (ASV28) and Barnesiella (ASV497) had a direct negative relationship with the members of the diarrhea module. CONCLUSIONS: Taken together, our results suggest that the dynamic successions of calf gut microbiota and the interactions among some bacteria could influence calf diarrhea, and some species of Prevotella might be the core microbiota in both neonatal and weaning calves, while species of Muribaculaceae might be the core microbiota in weaning calves for preventing calf diarrhea. Some ASVs affiliated with Prevotella_2 (ASV4 and ASV26), Prevotella_9 (ASV43), Alloprevotella (AVS14), unclassified Muribaculaceae (ASV28 and ASV44), UBA1819 (ASV151), Ruminococcaceae_UCG-005 (ASV254), and Barnesiella (ASV497) might be proper probiotics for preventing calf diarrhea whereas Clostridium_sensu_stricto_1 (ASV48) might be the biomarker for diarrhea risk in specific commercial farms.
RESUMEN
OBJECTIVE: This study identified the major lactic acid bacteria (LAB) strains from different fermented total mixed rations (FTMRs) via metataxonomic analysis and evaluated the ability of their standard strain as ensiling inoculants for corn stover silage. METHODS: The bacterial composition of eight FTMRs were analyzed by 16S rDNA sequencing. Corn stover was ensiled without LAB inoculation (control) or with 1×106 cfu/g LAB standard strain (Lactobacillus vaginalis, Lactobacillus reuteri, Lactobacillus helveticus, or Lactobacillus paralimentarius) selected from the FTMRs or 10 g/t commercial silage inoculant (CSI) around 25°C for 56 days. For each inoculation, a portion of the silage was sampled to analyze ensiling characteristics at time intervals of 0, 1, 3, 7, 14, 28, and 56 days, gas production (GP), microbial crude protein and volatile fatty acids as the measurements of rumen fermentation characteristics were evaluated in vitro with the silages of 56 days after 72 h incubation. RESULTS: Lactobacillus covered >85% relative abundance of all FTMRs, in which L. pontis, L. vaginalis, L. reuteri, L. helveticus, and L. paralimentarius showed >4% in specific FTMRs. CSI, L. helveticus, and L. paralimentarius accelerated the decline of silage pH. Silage inoculated with L. paralimentarius and CSI produced more lactic acid the early 14 days. Silage inoculated with L. paralimentarius produced less acetic acid and butyric acid. For the in vitro rumen fermentation, silage inoculated with CSI produced more potential GP, isobutyric acid, and isovaleric acid; silage inoculated with L. helveticus produced more potential GP and isovaleric acid, silage inoculated with L. paralimentarius or L. reuteri produced more potential GP only. CONCLUSION: The standard strain L. paralimentarius (DSM 13238) is a promising ensiling inoculant for corn stover silage. The findings provide clues on strategies to select LAB to improve the quality of silage.
RESUMEN
The production and consumption of pineapple creates large quantities of residues. Ensiling these residues might help to minimize the waste burden and meet the intensive feed demand for ruminants. Proper lactic acid bacteria (LAB) are not only responsible for pineapple residual silage fermentation, but might also deliver probiotics. The aim of this study was to isolate LAB strains with probiotic functions, and to enhance intestinal antioxidant capacity from naturally fermented pineapple residues. A total of 47 LAB isolates with gram-positive, catalase-negative, nonhemolytic properties were used for probiotic screening. Lactiplantibacillus plantarum (L. plantarum) A1, C1 and C10 were susceptible to rifampicin, gentamicin and erythromycin, did not contain virulence factor-coding genes and showed good tolerance to acid (pH 3.0), 0.5% bile salt and simulated gastric and intestinal fluid. Their hydrophobicity indices were 71.92%, 45.50% and 66.90%, respectively. All of them were able to adhere to bovine jejunum epithelial cells (BJECs) and to antagonize Escherichia coli F5 and Salmonella Dublin. These three LAB strains tolerated hydrogen peroxide and significantly decreased (p < 0.05) reactive oxygen species levels in BJECs. In addition, L. plantarum C1 and C10 significantly increased (p < 0.05) the total antioxidant capacity in BJECs in the presence of 200 µmol/L hydrogen peroxide condition. L. plantarum A1, C1 and C10 are potential probiotics isolated from pineapple residual silage. This study aims to promote pineapple residue's utilization in the feed industry.
RESUMEN
Introduction: Limosilactobacillus reuteri is a gut symbiont with multiple remarkable beneficial effects on host health, and members of L. reuteri are valuable probiotic agents. However, L. reuteri showed obvious host specificity. Methods: In our study, a novel L. reuteri RGW1 was isolated from feces of healthy calves, and its potential as a probiotic candidate were assessed, by combining in vitro, in vivo experiments and genomic analysis. Results and discussion: RGW1 was sensitive to all the antibiotics tested, and it did not contain any virulence factor-coding genes. This isolate showed good tolerance to acid (pH 3.0), 0.3% bile salt, and simulated gastric fluid. Moreover, this isolate showed a high hydrophobicity index (73.7 ± 4.6%) and was able to adhere to Caco-2 cells, and antagonize Escherichia coli F5. Treatment of LPS-induced mice with RGW1 elevated TGF-ß and IL-10 levels, while RGW1 cell-free supernatant (RCS) decreased TNF-α levels in the sera. Both RGW1 and RCS increased the villus height and villus height/crypt depth ratio of colon. Genomic analysis revealed the mechanism of the probiotic properties described above, and identified the capacity of RGW1 to biosynthesize L-lysine, folate, cobalamin and reuterin de novo. Our study demonstrated the novel bovine origin L. reuteri RGW1 had multiple probiotic characteristics and immunomodulation effects, and provided a deeper understanding of the relationship between these probiotic properties and genetic features.
