Insulin-like growth factor 2 as a central regulator of growth and metabolic efficiency in livestock: Genetic, nutritional, and biotechnological perspectives.

Abstract

Efficient livestock production depends on integrating genetic, nutritional, and management strategies to improve growth, feed efficiency, and product quality. Among genes linked to growth regulation, the insulin-like growth factor 2 ( IGF2 ) gene has become a key molecular regulator affecting muscle development, nutrient metabolism, carcass composition, and overall production efficiency across various livestock species. This review summarizes current knowledge about the biological roles, genetic regulation, nutritional influences, and biotechnological uses of IGF2 in livestock systems. IGF2 plays a key role in prenatal and early postnatal growth by promoting myoblast proliferation, muscle fiber differentiation, and protein synthesis through major signaling pathways, including PI3K/AKT and MAPK/ERK. Genetic polymorphisms in regulatory regions of IGF2 have consistently been linked to economically important traits such as increased body weight, improved feed conversion ratio, higher lean meat yield, and less fat deposition in cattle, pigs, poultry, and small ruminants. These findings support using IGF2 as a molecular marker in marker-assisted and genomic selection programs aimed at boosting livestock productivity. Along with genetic factors, IGF2 expression is heavily affected by nutritional status, environmental conditions, and epigenetic regulation. Maintaining a balanced intake of dietary energy and protein, proper management, and reducing stress levels can boost IGF2 activity, leading to improved growth efficiency and metabolic performance. Recent advancements in biotechnology, such as genome editing, epigenetic modulation, and transcriptomic techniques, offer new ways to control IGF2 expression for developing high-performance livestock while preserving product quality and animal welfare. However, excessive or uncontrolled modulation of IGF2 may disrupt metabolic balance, immune function, and physiological homeostasis, highlighting the need for careful regulation and ethical consideration in genetic improvement programs. Overall, IGF2 represents a crucial molecular link between genetics, nutrition, and physiology, and its integrated application in breeding, feeding, and biotechnology strategies offers promising prospects for sustainable and efficient livestock production.