# Effects of Rumen-Protected Methionine on Meat Quality, Fatty Acid Composition, Volatile Flavor Compounds and Transcriptomics of Longissimus lumborum of Yak (Bos grunniens)

## TL;DR

This study shows that adding rumen-protected methionine to yak diets improves meat quality, fatty acid balance, and flavor compounds.

## Contribution

The study reveals novel insights into how RPM affects yak meat quality and gene expression in muscle tissue.

## Key findings

- RPM supplementation increased intramuscular fat and improved fatty acid composition in yak meat.
- RPM altered the expression of hundreds of genes in the Longissimus lumborum muscle of yaks.
- Transcriptomic analysis identified enriched pathways linked to meat quality and flavor in RPM-treated yaks.

## Abstract

Yak (Bos grunniens) meat is popular with a unique flavor and high nutritional value. This study investigated the effects of dietary supplementation with rumen-protected methionine (RPM) on meat quality, fatty acid composition, volatile flavor compounds, and transcriptomics of Longissimus lumborum of yak. Twenty-four male Maiwa yaks were selected and assigned to four groups: basal diet (CON), or supplementation of 5 g/d (RPM5), 10 g/d (RPM10), and 15 g/d (RPM15) RPM. The dose-dependent effects of RPM levels were evaluated through linear or quadratic trend analysis. The results showed that diet supplementation with RPM increased the intramuscular fat contents, improved composition of volatile flavor compounds and the ratio of monounsaturated fatty acids to saturated fatty acids. Compared to the CON group, there were 36, 84 and 23 up-regulated genes, and 85, 94 and 70 down-regulated genes in the RPM5, RPM10 and RPM15 groups, respectively. Gene ontology enrichment analysis revealed significant differentially expressed genes enrichment in biological processes, cellular components, and molecular functions across RPM5, RPM10, and RPM15 groups compared to the CON. KEGG pathway analysis revealed 99, 169, and 104 enriched pathways in RPM5, RPM10, and RPM15 groups, respectively. In summary, the addition of RPM to diets may provide new ideas and methods to improve meat quality of yaks.