Serine governs metabolic homeostasis and microbial crosstalk to promote the utilization of urea nitrogen in rumen fermentation in vitro

作者：Yunan Weng, Yueyue Qin, Haoran Cao, Ziyi Tang, Xiujuan Zhao, Hosameldeen Mohamed Husien, Ahmed A. Saleh, Hongrong Wang · 发表于：Journal of the Science of Food and Agriculture · 年份：2025 · DOI：10.1002/jsfa.14425 · 被引用次数：3 · 研究领域：Ruminant Nutrition and Digestive Physiology、Animal health and immunology、Reproductive Physiology in Livestock

BACKGROUND: Urea is commonly used as a protein substitute in ruminant diets due to its nitrogen utilization efficiency and cost-effectiveness. Serine-derived downstream metabolism contributes to urea-enriched metabolic pathways in rumen fluid. RESULTS: dry matter serine supplementation on fermentation parameters and microbial communities in urea-based substrates. Fifteen amino acids were detected in the fermentation fluid. Urea-based substrates exhibited distinct amino acid profiles compared to the control basal substrate, with lower levels of most amino acids except cysteine (Cys), leucine (Leu), and phenylalanine (Phe). Serine supplementation increased propionate production, microbial protein synthesis, and dry matter digestibility, while decreasing isovalerate, isoleucine (Ile), and Leu levels. Additionally, serine supplementation altered microbial populations, increasing Ruminobacter and Bacteroidales_BS11_gut_group by 24.47% and 26.42%, respectively, while decreasing Prevotella and WCHB1-41 by 9.30% and 24.15%, respectively. Glycine and folate, which are downstream metabolites of serine, exhibited partial similarity to serine regarding their influence on fermentation profiles. Notably, serine reduced the fermentation of Leu and Ile into isovalerate, irrespective of their supplementation, exhibiting a dosage-dependent effect. CONCLUSIONS: In short, serine supplementation in urea-based substrates enhances fermentation, promoting the utilization of urea nitrogen and amino a...