Molecular Mechanisms and Regulatory Factors Governing Feed Utilization Efficiency in Laying Hens: Insights for Sustainable Poultry Production and Breeding Optimization.

Since the early 2000s, the poultry industry in our nation has steadily progressed towards a larger scale and increased intensification. However, the growing demand for animal-based protein, combined with significant increases in feed ingredient costs, presents substantial challenges to the advancement of egg production. The regulation of feed utilization efficiency in laying hens is a complex process, influenced by various factors including the farming environment, feed composition, microbial ecosystems, and hormonal dynamics. The feed conversion rate in laying hens not only serves as a critical indicator of agricultural productivity but also highlights the significant impact of molecular technologies in improving feed efficiency. These technological advancements have enhanced the precision and effectiveness of breeding practices while providing substantial support for optimizing feed management, improving production metrics, and promoting sustainable agricultural practices. This comprehensive synthesis of factors, regulatory pathways, and cutting-edge molecular methodologies establishes a biological framework for future breeding strategies. Notably, this review uniquely emphasizes the pivotal role of modern molecular biology techniques-such as genomic selection, transcriptomic profiling, and gene-editing tools-in decoding feed conversion efficiency (FCE), contributing to broader goals of agricultural sustainability by balancing productivity gains with eco-friendly and cost-effective egg production.