Rumen-protected glucose supplementation alters fecal microbiota and its metabolic profiles in early lactation dairy cows

Effects of Dietary Rumen-Protected Glucose and Rumen-Protected Taurine Levels on Growth Performance, Serum Biochemical Indicators, and Liver Health in Yaks

Yaks are an important livestock species on the Tibetan Plateau, but traditional grazing practices cause a sharp drop in their weight during winter, leading to grassland degradation due to overgrazing. Although off-site fattening can improve performance and protect ecology, it often leads to a negative energy balance, liver metabolism disorders, and immune impairment due to stress. However, the effects of rumen-protected glucose (RPG) and rumen-protected taurine (RPT) on yak liver health are not yet clear. The purpose of this study was to evaluate the effects of dietary RPG and RPT levels on the growth performance, serum biochemical parameters, liver antioxidant capacity, and immunity of yaks. Twenty-eight healthy yaks weighing 170 ± 10.4 kg were randomly divided into four treatments: LGLT (RPG: 1%-low RPG [LG]; RPT: 5 g/d-low RPT [LT]), LGHT (RPG: 1%-low RPG [LG]; RPT: 20 g/d-high RPT [HT]), HGLT (RPG: 3%-high RPG [HG]; RPT: 5 g/d-low RPT [LT]), and HGHT (RPG: 3%-high RPG [HG]; RPT: 20 g/d-high RPT [HT]). The results showed that compared with the LTHT treatment group, the HGHT group upregulated the serum concentrations of glucose (p = 0.004) and Interleukin-10 (p = 0.03), the relative mRNA expression of small heterodimer partners (p = 0.01), and the sterol 12-alpha-hydroxylase (p < 0.001), while reducing the serum concentration of gamma-glutamyl transferase (p = 0.048). The serum concentration of hepatic protein carbonyl (p = 0.005) and malondialdehyde (p = 0.03) was lower in the LGHT and HGHT treatment groups than in the LGLT and HGLT groups. The relative mRNA expression of Toll-like receptor 4 (p = 0.02), Interleukin-8 (p < 0.01), and Interleukin-1β (p < 0.01) was lower in the LGHT and HGHT groups than in the LGLT and HGLT groups. Tumor necrosis factor expression was lower (p = 0.04) and glucose transporter 2 expression was higher (p < 0.01) in the HGHT group compared to other treatment groups. The expression of glucokinase, glycogen synthase, pyruvate kinase, and farnesoid X receptor was higher in the HGLT treatment group than in other treatments (p < 0.01). In conclusion, dietary supplementation with 3% PRG and 5 g/d PRT can enhance liver antioxidant capacity and immune function, reduce lipid peroxidation, and promote glucose and bile acid metabolism in yaks.

Aloe arborescens supplementation in drying-off dairy cows: influence on rumen, rectum and milk microbiomes

BACKGROUND

In the context of the RABOLA project, which aimed to identify operational practices that lead to the reduction of antibiotic use in dairy cattle farming, lyophilised Aloe arborescens was administered orally to cows during the dry-off and peripartum periods. In this specific paper we wanted to examine whether oral administration of Aloe arborescens, in combination with the topical application of a teat sealant could exert an effect on the microbial populations of three cow microbiomes (rumen, milk, rectum), between dry-off and peripartum. Dry-off and peripartum are critical physiological phases of the cow's life, where both the mammary gland and the gastrointestinal tract undergo dramatic modifications, hence the relevance of evaluating the effects of dietary treatments.

METHODS

Thirty multiparous dairy cows were randomly allocated to three groups: Control (antibiotic treatment and internal teat sealant), Sealant (only internal teat sealant) and Aloe (internal teat sealant and Aloe arborescens homogenate administered orally). For 16S rRNA gene sequencing, rumen, rectum and milk samples were collected, not synchronously, at the most critical timepoints around dry-off and calving, considering the physiological activity of each biological site.

RESULTS

The rumen microbiome was predominantly characterized by Bacteroidetes and Firmicutes followed by Proteobacteria, while the rectum exhibited a prevalence of Firmicutes and Bacteroidetes. The milk microbiome mainly comprised Firmicutes, Proteobacteria, Actinobacteria and Bacteroidetes. Alistipes spp., Ruminococcaceae UCG-10 group, Prevotellaceae UCG-001 group, and Bacteroides spp., involved in cellulose and hemicellulose degradation, enhancement of energy metabolism, and peptide breakdown, showed increment in the rectum microbiome with Aloe supplementation. The rectum microbiome in the Aloe group exhibited a significant increase in the Firmicutes to Bacteroidetes ratio and alpha-diversity at seven days after dry-off period. Beta-diversity showed a significant separation between treatments for the rectum and milk microbiomes. Aloe supplementation seemed to enrich milk microbial composition, whereas the Sealant group showed greater diversity compared to the Control group, albeit this included an increase in microorganisms frequently associated with mastitis.

CONCLUSIONS

Aloe arborescens administration during the dry-off period did not demonstrate any observable impact on the microbial composition of the rumen, a finding further supported by volatilome analysis. Instead, the oral Aloe supplementation at dry-off appears to significantly influence the composition of the dairy cow rectum and milk microbiomes in the following lactation.

Analysis of the microbial diversity in takin (Budorcas taxicolor) feces

Introduction

The intestinal tract of animals is a complex and dynamic microecosystem that is inextricably linked to the health of the host organism. Takin (Budorcas taxicolor) is a threatened species, and its gut microbiome is poorly understood. Therefore, this study aimed to analyze the microbial community structure and potential pathogens of takin.

Methods

Takin fecal samples were collected from five sites in a nature reserve to ensure the uniformity of sample collection, determine the effects of different geographical locations on gut microbes, and analyze the differences in microbial communities between sites. Subsequently, high-throughput 16S rDNA gene sequencing was performed to analyze the microbial diversity and potential pathogens in the gut; the findings were verified by isolating and culturing bacteria and metagenomic sequencing.

Results and discussion

The takin gut microflora consisted mainly of four phyla: Firmicutes (69.72%), Bacteroidota (13.55%), Proteobacteria (9.02%), and Verrucomicrobiota (3.77%), representing 96.07% of all microorganisms. The main genera were UCG-005 (20.25%), UCG-010_unclassified (12.35%), Firmicus_unclassified (4.03%), and Rumino coccsea_unclassified (3.49%), while the main species were assigned to Bacteria_unclassified. Potential pathogens were also detected, which could be used as a reference for the protection of takin. Pseudomonas presented the highest abundance at Shuichiping and may represent the main pathogen responsible for the death of takin at the site. This study provides an important reference for investigating the composition of the bacterial community in the intestine of takin.