Ruminal Transcriptomic Analysis of Grass-Fed and Grain-Fed Angus Beef Cattle.

Area of Science:

• Animal Science
• Molecular Biology
• Biochemistry

Background:

• Beef is a primary protein source, with increasing demand for grass-fed varieties due to environmental and health concerns.
• Grass-fed cattle consume high-fiber diets, while grain-fed cattle receive high-energy diets, potentially impacting rumen function.
• Ruminant animals, including cattle, are significant contributors to greenhouse gas emissions.

Purpose of the Study:

• To identify differentially expressed genes in the ruminal wall of grass-fed versus grain-fed steers.
• To explore potential biological pathways affected by different feeding regimens.
• To understand the molecular mechanisms underlying phenotypic differences in cattle based on diet.

Main Methods:

• RNA Sequencing (RNA-Seq) was employed to quantify gene expression levels in ruminal wall tissue.
• Differential gene expression analysis was performed to identify genes with significant expression changes.
• Ingenuity Pathway Analysis (IPA) was used to determine enriched molecular networks and biological pathways.

Main Results:

• A total of 342 differentially expressed genes were identified between the two feeding groups.
• Sixteen significant molecular networks and 13 significantly enriched biological pathways were detected.
• The majority of enriched pathways were associated with cell development and biosynthesis.

Conclusions:

• Significant differences in gene expression exist in the ruminal wall of cattle based on diet (grass-fed vs. grain-fed).
• These molecular differences are primarily linked to pathways involved in cell development and biosynthesis.
• The study provides insights into the molecular basis of dietary impacts on cattle physiology and phenotype.