Intramuscular Fat Deposition in pig: A Key Target for Improving Pork Quality1

Intramuscular fat (IMF) is an important economic trait for pork quality, affecting meat flavour, juiciness, and tenderness. Hence, the improvement of IMF content is one of the hotspots of animal science to provide better meat product. Here, we found that most IMF-related genes are enriched in lipid metabolism processes, including fatty acid transport and uptake, fatty acid beta oxidation, lipid synthesis, lipid storage, and lipolysis. PPAR and AMPK signalling pathways are identified to be responsible for IMF deposition. Genetics and nongenetic factors (i.e., diets, gut microbiota, age, sex, management) also positively or negatively regulate the IMF content in pigs. Taken together, this review deepens our understanding of how these factors affect pig IMF deposition and provides valuable information for moderately increasing IMF content.