Hepatic transcriptome perturbations in dairy cows fed different forage resources.

Area of Science:

• Animal Science
• Metabolomics
• Bioinformatics

Background:

• China faces a deficit in high-quality alfalfa hay for dairy cows, necessitating alternative forage sources.
• Corn stover is abundant in China, presenting an opportunity for utilization as dairy forage.
• The impact of different forage resources on dairy cow liver metabolism remains largely unexplored.

Purpose of the Study:

• To investigate the effects of corn stover (CS) versus mixed forage (MF) on dairy cow liver metabolism.
• To identify molecular mechanisms underlying metabolic changes in response to varying forage quality.

Main Methods:

• RNA sequencing (RNAseq) was employed to analyze liver gene expression.
• Bioinformatics tools including KEGG, DAVID, and ClueGO were used for pathway and functional enrichment analysis.
• Co-expression network analysis was performed to identify key regulatory genes.

Main Results:

• Cows fed CS diets exhibited lower milk yield, dry matter intake (DMI), milk protein, milk fat, and lactose compared to MF diets.
• RNAseq revealed significant downregulation of genes involved in glycan biosynthesis, amino acid metabolism, cell-cell adhesion, and multicellular organism growth in the CS group.
• Key genes such as FAM210A, SLC26A6, and FBXW5 were identified in co-expression networks enriched for pyruvate metabolism and endosome-to-Golgi transport.

Conclusions:

• Low-quality forage diets, like CS, can impair crucial liver functions, partly due to reduced DMI.
• This study provides insights into the liver's metabolic response to different forage qualities.
• Findings can inform strategies for improving corn stover utilization in Chinese dairy production.