Heated drinking water in winter improves growth performance of male Hu sheep by modulating rumen quorum sensing and metabolites, and enhancing serum antioxidant capacity.

Objective: This study aimed to explore the mechanism by which increasing the temperature of drinking water in winter promotes sheep growth from a microbial perspective.

Methods: A total of 12 healthy male Hu sheep were evenly divided into two groups: one with drinking water at 12°C (WT12) and the other at 25°C (WT25), and they were raised for 60 days in the cold winter.

Results: The WT25 group exhibited higher average daily gain, serum immunoglobulin G, total antioxidant capacity, glutathione peroxidase, and superoxide dismutase, along with lower feed-to-gain ratio, serum cortisol, malondialdehyde, reactive oxygen species, and oxidative stress index when compared to the WT12 group (p<0.05). The concentrations of microbial crude protein, microbial density, autoinducer-2 (AI-2) signaling molecule concentration, and biofilm formation were higher in the WT25 group, while the ammonia nitrogen concentration was lower (p<0.05). The relative abundances of Muribaculum and Clostridia UCG-014, as well as the predicted metabolic pathways related to lipid metabolism, were lower in the WT25 group, whereas the metabolism of other amino acids showed increased abundances (p<0.05). Both principal coordinates analysis (PCoA) and analysis of similarities (ANOSIM) revealed no significant differences in rumen microbial communities between the WT12 and WT25 groups (p>0.05). Metabolomics analysis identified 12 differential metabolites, four of which were correlated with Muribaculum, Raoultibacter, and Coriobacteriales Incertae Sedis.

Conclusion: These results indicate that heated drinking water in winter could improve growth performance by increasing rumen bacterial biofilm formation and enhancing serum antioxidant capacity in Hu sheep. This study establishes correlations between rumen microbial quorum sensing and key factors such as animal growth phenotypes, rumen metabolic characteristics, and specific bacterial genera. It offers innovative perspectives on enhancing animal feed efficiency through the modulation of rumen bacterial quorum sensing.