| Summary: | This study aimed to evaluate the effect of feeding ethyl cellulose rumen-protected methionine (RPM) on skeletal muscle mRNA abundance during the periparturient period. Sixty multiparous Holstein cows were used in a block design and assigned to either a control or RPM diet. The RPM was supplied from −28 to 60 days in milk (DIM) at a rate of 0.09% (prepartum) or 0.10% (postpartum) of dry matter (DM), ensuring a Lys:Met in the metabolizable protein of ~2.8:1. Muscle biopsies were collected at −21, 1, and 21 DIM. Thirty-five target genes associated with nutrient metabolism and biochemical pathways were measured via RT-qPCR. The mRNA abundance of genes associated with amino acid (AA) transport (<i>SLC7A8</i>, <i>SLC43A2</i>), carnitine transport (<i>SLC22A5</i>), insulin signaling (<i>IRS1</i>), and antioxidant response (<i>NFE2L2</i>) had diet × time effect (<i>p</i> < 0.05) due to greater abundance in RPM versus CON cows, especially at 1 and 21 DIM. Members of the AA transport (<i>SLC7A8</i>, <i>SLC25A29</i>, <i>SCL38A9</i>), fatty acid β-oxidation (<i>ACADVL</i>), vitamin transport (<i>SLC5A6</i>, <i>SLC19A2</i>), mTOR pathway (<i>AKT1</i> and <i>mTOR</i>), antioxidant response (<i>KEAP1</i>, <i>CUL3</i>), CDP-Choline pathway and arginine metabolism had overall greater abundance (<i>p</i> < 0.05) in RPM versus CON cows. Overall, data indicate that RPM can alter nutrient metabolism in the skeletal muscle around parturition partly through alterations in mRNA abundance.
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