The amount of fat within beef muscle, known as intramuscular fat (IMF) or marbling, is a key factor that influences meat tenderness and juiciness—two key attributes that directly impact consumer satisfaction. The development of IMF occurs mainly during late pregnancy and in the first months after birth, a period called the “marbling window”. Research suggests that specific nutrients such as vitamin A may enhance this process at early stages of life. Vitamin A is known to influence fat development at the molecular level by promoting the formation of fat cells within the muscle. Our study used RNA sequencing to investigate how vitamin A supplementation at birth affects fat development in feedlot-finished beef steers. We show that vitamin A influences the expression of genes within metabolic pathways involved in lipid metabolism and IMF deposition in crossbred beef steers. Specifically, we provide new evidence suggesting that the PI3K-Akt signaling pathway plays a crucial role in fat cell formation and lipid accumulation. These results contribute to a better understanding of how early-life nutrition can impact beef quality.

Read the full article in the Journal of Animal Science.