Addressing Two Systemic Bottlenecks in Global Poultry Production: A Review of Non-Destructive Pre-Incubation Freshness and In-Ovo Sex Detection

The $300-billion global poultry industry, a cornerstone of food security, faces two interconnected systemic challenges: pre-incubation quality degradation wastes up to 15% of incubation capacity on non-viable eggs, while post-hatch male chick culling results in the annual euthanasia of 7 billion day-old layer chicks. Existing non-destructive detection research remains fragmented, treating pre-incubation freshness assessment and in ovo sexing as disconnected domains and creating a persistent lab-to-field gap that blocks industrial translation. This review establishes a unified process-centric framework covering the full detection workflow, and critically evaluates state-of-the-art sensing modalities across the entire hatching cycle. The analysis demonstrates that implementation bottlenecks do not reside in laboratory classification accuracy, which frequently exceeds 90% under controlled conditions, but in cross-batch generalizability, embryonic biosafety assurance, and high-throughput online operation. A hierarchical detection strategy with closed-loop traceability is outlined to bridge the lab-to-field gap. This work provides a structured roadmap to improve both economic efficiency and ethical sustainability of global poultry production.