Analysis of Host Jejunum Transcriptome and Associated Microbial Community Structure Variation in Young Calves with Feed-Induced Acidosis

Regulation of the growth performance and the gastrointestinal microbiota community by the addition of defective pear fermentation to feed of small-tailed Han sheep

This study investigated the effects of defective pear fermentation (DPF) diets on growth performance and gastrointestinal microbial communities in 60 healthy male small-tailed Han sheep, aged 90 days. The sheep were randomly divided into four groups, each consisting of three replicates with five sheep per replicate. Initially, all groups received a basal diet for seven days during the adaptation stage. Subsequently, for 60 days, group C (control) was fed a basal diet, group X received a basal diet with 2% DPF, group Y had a basal diet with 4% DPF, and group Z was fed a basal diet with 6% DPF. The results indicated that group Y experienced a significant increase in average daily gain (ADG) and average daily feed intake (ADFI). The addition of DPF significantly elevated the levels of GSH-Px and notably reduced MDA content compared to group C. Analysis of gastrointestinal microbiota showed that groups receiving DPF had increased relative abundances of Lachnospiraceae_NK3A20_group, norank_f p-2534-18B5_gut_group, Acetitomaculum, Actinobacteriota, Bacteroidota and Ruminococcus_gauvreauii_group, and decreased abundances of Proteobacteria, Prevotella, Staphylococcus, and Psychrobacter compared to group C. Group X exhibited the highest relative abundance of Olsenella, while group Y showed a significant increase in unclassified_f Lachnospiraceae compared to the other groups. Bacterial function prediction indicated that pathways related to energy metabolism were more prevalent in group X and Y. This study preliminarily confirms the feasibility of using DPF as feed additives, providing a foundation for further research and evaluation of DPF's application in animal production.

Correlation of Ruminal Fermentation Parameters and Rumen Bacterial Community by Comparing Those of the Goat, Sheep, and Cow In Vitro

In this study, we aimed to establish the correlation between ruminal fermentation parameters and the bacterial community by comparing those of the goat, sheep, and cow, thus illustrating the main bacteria causing the difference in rumen fermentation among goats, sheep, and cows and providing a new idea for improving the feed digestibility of ruminants. Rumen fluid from goats (Taihang White cashmere goat, n = 6), sheep (Hu sheep, n = 6), and cows (Holstein cow, n = 6) was collected using oral intubation and immediately brought back to the laboratory for a fermentation test with the same total mixed ration (TMR) feed in vitro. The rumen bacterial composition was measured by high-throughput sequencing of 16S rRNA genes in the MiSeq platform, the gas production (GP) was recorded after 2, 4, 6, 8, 10, 12, 24, 36, and 48 h of fermentation, and the feed nutrient digestibility and the rumen fluid parameters were determined after 48 h of fermentation. The results showed that the 48 h GP of the sheep group was higher than that of the cow group (p < 0.05), and the theoretical maximum GP was higher than that of the goat and cow groups (p < 0.05). The organic matter digestibility (OMD), dry matter digestibility (DMD), crude protein digestibility (CPD), and gross energy digestibility (GED) of the sheep group were higher than those of the goat and cow groups (p < 0.05). The ammonia nitrogen (NH3-N), microbial protein (MCP), and total volatile fatty acids (TVFA) concentrations of the sheep group were higher than those of the other groups (p < 0.05), and the pH of the sheep group was lower than those of the other groups (p < 0.05). The 16S rRNA gene sequencing revealed that bacterial composition also differed in the rumens of the sheep, goat, and cow groups (ANOSIM, p < 0.05). We then used a random forest machine learning algorithm to establish models to predict the fermentation parameters by rumen bacterial composition, and the results showed that rumen bacterial composition could explain most of the ruminal fermentation parameter variation (66.56%, 56.13%, 65.75%, 80.85%, 61.30%, 4.59%, 1.41%, −3.13%, 34.76%, −25.62%, 2.73%, 60.74%, 76.23%, 47.48%, −13.2%, 80.16%, 4.15%, 69.03%, 32.29%, and 89.96% for 48 h GP, a (GP of quickly degraded part), b (GP of slowly degraded part), c (GP rate), a + b (theoretical maximum GP), DMD, OMD, GED, CPD, NDFD, ANDF, pH, NH3-N, MCP, acetic acid, propionic acid, butyric acid, valeric acid, TVFA, and A:P (acetic acid–propionic acid ratio), respectively). A correlation analysis revealed that Lactobacillus, Prevotellaceae_UCG-003, Selenomonas, Peptostreptococcus, and Olsenella significantly correlated with most in vitro fermentation parameters (p < 0.05). A comprehensive analysis showed that rumen fermentation parameters and bacterial composition differed in goats, sheep, and cows. The ruminal fermentation parameters of GP, a, b, c, a + b, pH, NH3-N, propionic acid, valeric acid, and A:P could be accurately predicted by rumen bacteria (explanation > 55% of variation), and the Lactobacillus, Prevotellaceae_UCG-003, Olsenella, Selenomonas, and Peptostreptococcus were the main bacteria that affected the in vitro fermentation parameters of goats, sheep, and cows.

Differential Responses of Digesta- and Mucosa-Associated Jejunal Microbiota of Hu Sheep to Pelleted and Non-Pelleted High-Grain Diets

In the present study, we utilized 16S rRNA sequencing to uncover the impacts of non-pelleted (HG) or high-grain pelleted (HP) diets on the microbial structure and potential functions of digesta- and mucosa-associated microbiota in the jejunum of Hu sheep. Here, we randomly assigned 15 healthy male Hu sheep into three groups and fed the control diets (CON), HG, and HP diets, respectively. The experiment period was 60 days. The HP diets had the same nutritional ingredients as the HG diets but in pelleted form. At the finish of the experiment, the jejunal digesta and mucosa were gathered for microbial sequencing. The results of PCoA and PERMANOVA showed that different dietary treatments had significant impact (p < 0.05) on digesta- and mucosa-associated microbiota in the jejunum of Hu sheep. For specific differences, HG diets significantly increased (p < 0.05) the abundance of some acid-producing bacteria in both jejunal digesta (Bifidobacterium, OTU151, and OTU16) and mucosa (Rikenellaceae RC9 gut group, and Bifidobacterium) of Hu sheep compared with the CON diets. Besides the similar effects of the HG diets (increased the acid-producing bacteria such as Olsenella, Pseudoramibacter, and Shuttleworthia), our results also showed that the HP diets significantly decreased (p < 0.05) the abundance of some pro-inflammatory bacteria in the jejunal digesta (Mogibacterium, and Marvinbryantia) and mucosa (Chitinophaga, and Candidatus Saccharimonas) of Hu sheep compared with the HG diets. Collectively, these findings contributed to enriching the knowledge about the effects of HG diets on the structure and function of intestinal microbiota in ruminants.

Transcriptome and iTRAQ-Based Proteome Reveal the Molecular Mechanism of Intestinal Injury Induced by Weaning Ewe's Milk in Lambs

Early feeding regime has a substantial lifelong effect on lambs and weaning ewe's milk can lead to the intestinal injury of lambs. To explore the molecular regulatory mechanism of intestinal injury of lambs under weaning stress, the jejunum was conducted transcriptome and then integrated analyzed with our previous proteome data. A total of 255 upregulated genes and 285 downregulated genes were significantly identified. These genes showed low overlapping with differentially expressed proteins identified by isobaric tags for relative and absolute quantification (iTRAQ). However, according to their functions, the differentially expressed genes (DEGs) and proteins with the same expression trend were enriched for the similar Gene Ontology (GO) terms and the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, such as intestinal lipid absorption, urea cycle, peroxisome proliferator-activated receptor (PPAR) signaling pathway, and ferroptosis. Furthermore, the DEGs, including FABP2, ACSL3, APOA2, APOC3, and PCK1, might play essential roles in intestinal lipid absorption and immune response through the PPAR signaling pathway and ferroptosis. This study could provide new insights into early lamb breeding at the molecular level.