The Effect of Combining Millet and Corn Straw as Source Forage for Beef Cattle Diets on Ruminal Degradability and Fungal Community

Housed feeding improves rumen health by influencing the composition of the microbiota in Honghe cattle

Rumen is one of the most vital organs for the digestion of ruminants and is influenced by factors including feeding patterns and nutrition. How rumen microbiota and barrier function change are affected feeding patterns requires attention, particularly for beef cattle. In the present study, the Honghe cattle under grazing (CON group, n = 10) and housed feeding (HES group, n = 10) conditions were selected as a model of different rumen microbiota and observed for 180 days. The indicators of immunity and antioxidants in serum and rumen epithelium of cattle were measured; and the rumen microbiota were evaluated by using 16S rRNA and ITS sequencing techniques. In the present study, the concentrations of total protein, albumin and glucose in serum of Honghe cattle were significantly increased by the HES group when compared with CON group (p < 0.05). The HES group reduced the levels of complement 3, complement 4, interleukin-4, interleukin-10, interleukin-1β and tumor necrosis factor α, but increased the levels of total antioxidant capacity (T-AOC) and superoxide dismutase (SOD) (p < 0.05). We found that the HES group enhanced the levels of T-AOC and SOD in rumen epithelium (p < 0.05). Furthermore, there was a significant up-regulation of the relative mRNA expressions of ZO-1, OCC, SOD1, SOD2, Nrf2, NQO-1 and HO-1 observed in the HES group (p < 0.05). For rumen microbiota, the HES group significantly decreased alpha diversity. The core rumen bacterial communities were Bacteroidata, Firmicutes and Proteobacteria. The relative abundances of Prevotella and Ruminococcus were increased by the HES group, but norank_f_Bacteroidales_UCG-001, Rikenellaceae_RC9_gut_group and Prevotellaceae_UCG-003 were decreased (p < 0.05). Moreover, The HES group enhanced the relative abundance of Pichia, Cyllamyces, Sterigmatomyces and Wallemia (p < 0.05), but decreased Aspergillus and Candida (p < 0.05). There was a positive correlation between microorganisms such as Prevotella, Ruminococcus and Pichia and rumen epithelial barrier and antioxidant-related genes (p < 0.05). Overall, housed feeding contributed to the improvement of antioxidant capacity and rumen health in Honghe cattle, which may be related to the modulation of rumen microbiota including bacteria and fungi.

Gut Mycobiota of Three Rhinopithecus Species Provide New Insights Into the Association Between Diet and Environment

Gut mycobiota are part of the gut microbiome, typically derived from the host diet and living environment. In this study, we examined the gut mycobiota of three snub-nosed monkeys: Rhinopithecus roxellana, R. bieti, and R. strykeri using next-generation amplicon sequencing targeting the fungal internal transcribed spacer. The alpha diversity indexes of gut mycobiota in R. bieti were significantly higher than R. roxellana and R. strykeri, the beta diversity indicated that R. roxellana and R. bieti had more similar feeding habits. Core mycobiota demonstrated commonalities among the three species and potentially associated with feeding habits. Mycobiota displaying significant differences exhibited the respective characteristics of the host, likely associated with the hosts' living environment. Among them, animal and plant pathogenic fungi and lichen parasites are potential threats to the survival of snub-nosed monkeys for their pathogenicity to both monkeys and their food plants. Functionally, fungal trophic modes and functional guilds revealed a strong association between gut mycobiota and host diet. We found a higher abundance and more significant correlations with lichen parasitic fungi in R. strykeri than the other two species, indicating potential threats to their foods. Accordingly, this study revealed the basic structures of gut mycobiota of three wild Rhinopithecus species and highlighted the associations between gut mycobiota and their feeding habits and living environments. Furthermore, due to the close connection between fungi and the environment, animals could ingest fungi from their diet; thus, we speculate that gut mycobiota may serve a role in environmental monitoring for wildlife.

Analysis of fungal diversity in the gut feces of wild takin (Budorcas taxicolor)

Introduction

The composition of the intestinal microbiome correlates significantly with an animal's health status. Hence, this indicator is highly important and sensitive for protecting endangered animals. However, data regarding the fungal diversity of the wild Budorcas taxicolor (takin) gut remain scarce. Therefore, this study analyzes the fungal diversity, community structure, and pathogen composition in the feces of wild B. taxicolor.

Methods

To ensure comprehensive data analyses, we collected 82 fecal samples from five geographical sites. Amplicon sequencing of the internal transcribed spacer (ITS) rRNA was used to assess fecal core microbiota and potential pathogens to determine whether the microflora composition is related to geographical location or diet. We further validated the ITS rRNA sequencing results via amplicon metagenomic sequencing and culturing of fecal fungi.

Results and discussion

The fungal diversity in the feces of wild Budorcas taxicolor primarily comprised three phyla (99.69%): Ascomycota (82.19%), Fungi_unclassified (10.37%), and Basidiomycota (7.13%). At the genus level, the predominant fungi included Thelebolus (30.93%), Functional_unclassified (15.35%), and Ascomycota_unclassified (10.37%). Within these genera, certain strains exhibit pathogenic properties, such as Thelebolus, Cryptococcus, Trichosporon, Candida, Zopfiella, and Podospora. Collectively, this study offers valuable information for evaluating the health status of B. taxicolor and formulating protective strategies.

Effects of yeast culture on in vitro ruminal fermentation and microbial community of high concentrate diet in sheep

This research aimed to investigate effects of different yeast culture (YC) levels on in vitro fermentation characteristics and bacterial and fungal community under high concentrate diet. A total of 5 groups were included in the experiment: control group without YC (CON), YC1 (0.5% YC proportion of substrate dry matter), YC2 (1%), YC3 (1.5%) and YC4 (2%). After 48 h of fermentation, the incubation fluids and residues were collected to analyze the ruminal fermentation parameters and bacterial and fungal community. Results showed that the ruminal fluid pH of YC2 and YC4 groups was higher (P < 0.05) than that of CON group. Compared with CON group, the microbial protein, propionate and butyrate concentrations and cumulative gas production at 48 h of YC2 group were significantly increased (P < 0.05), whereas an opposite trend of ammonia nitrogen and lactate was observed between two groups. Microbial analysis showed that the Chao1 and Shannon indexes of YC2 group were higher (P < 0.05) than those of CON group. Additionally, YC supplementation significantly decreased (P < 0.05) Succinivibrionaceae_UCG-001, Streptococcus bovis and Neosetophoma relative abundances. An opposite tendency of Aspergillus abundance was found between CON and YC treatments. Compared with CON group, the relative abundances of Prevotella, Succiniclasticum, Butyrivibrio and Megasphaera elsdenii were significantly increased (P < 0.05) in YC2 group, while Apiotrichum and unclassified Clostridiales relative abundances were decreased (P < 0.05). In conclusion, high concentrate substrate supplemented with appropriate YC (1%) can improve ruminal fermentation and regulate bacterial and fungal composition.

Ecoinformatic Analysis of the Gut Ecological Diversity of Wild and Captive Long-Tailed Gorals Using Improved ITS2 Region Primers to Support Their Conservation

Ex situ conservation is used to protect endangered wildlife. As captive and wild long-tailed gorals are known to be similar, individuals under ex situ conservation can be reintroduced into nature. However, there is no appropriate indicator to evaluate them. Here, we amplified the internal transcribed spacer 2 (ITS2) region and compared the gut ecological information (eco-information) of captive and wild long-tailed gorals. We validated the existing ITS86F and ITS4 universal primers using reference sequences of the National Center for Biotechnology Information (NCBI) and improved their matching rates. We compared the gut eco-information of captive and wild long-tailed gorals obtained through experiments using the improved primer pair and found that the gut ecological diversity of captive gorals was low. Based on this, we suggested that the gut eco-information can be used as an evaluation index before reintroducing captive long-tailed gorals. Furthermore, we identified four plant types from the gut eco-information of wild long-tailed gorals, which can be the additional food sources to enhance the reduced intestinal ecological diversity of the captive animals.