CONCLUSION

Delayed ovulation in cattle represents a clinically important reproductive disorder characterized by postponed oocyte release following estrus, primarily driven by disruptions in the HPO axis. This review synthesizes current evidence on its physiological basis, multifactorial etiology (nutritional, environmental, animal-related, endocrine–metabolic, and infectious-inflammatory), clinical manifestations including follicular persistence and weak estrus expression, diagnostic approaches (ultrasonography, hormonal profiling, behavioral monitoring, and emerging biomarkers), and integrated management strategies encompassing hormonal therapies, nutritional optimization, environmental control, postpartum care, and ART. Key impacts include reduced conception rates, prolonged calving intervals, increased repeat breeding, and substantial economic losses estimated at USD 50–150 per affected cow per cycle, with greater effects observed in high-producing dairy systems.

The findings underscore the importance of early identification and targeted interventions. Routine integration of ovarian ultrasonography with metabolic monitoring (e.g., NEFA, BHB, IGF-1) and body condition scoring during the transition and early postpartum periods enables timely differentiation between physiological and pathological delays. Strategic use of GnRH-based synchronization protocols, FTAI, optimized transition diets targeting BCS 3.0–3.5, and heat stress abatement can significantly improve ovulation timing and herd fertility. Herd level implementation of these evidence-based practices supports more sustainable reproductive management across dairy and beef production systems.

This integrative review provides a comprehensive, cross-disciplinary synthesis that clearly distinguishes delayed ovulation from related conditions such as COD, silent heat, and anovulation. It bridges physiological mechanisms with practical field applications and highlights system-specific considerations, offering actionable guidance for veterinarians and livestock practitioners.

As a narrative review spanning 2000–2025 literature, it is subject to the inherent heterogeneity of study designs, diagnostic criteria, and production contexts. The predominance of observational data limits strong causal conclusions, and translational applicability may vary across diverse farming systems and breeds.

Priority research should focus on validating predictive biomarker panels, developing cost-effective PLF tools adaptable to resource-limited settings, establishing clear thresholds separating adaptive from pathological delays, and evaluating long-term welfare and economic outcomes of preventive versus therapeutic strategies. Multi-center, controlled trials and standardized protocols will be essential to strengthen the evidence base.

In conclusion, addressing delayed ovulation through integrated, evidence-based approaches holds substantial potential to enhance reproductive efficiency, reduce economic losses, and promote sustainable cattle production. By translating current knowledge into practical on-farm strategies while advancing targeted research, veterinarians and producers can achieve more precise, welfare-conscious, and productive reproductive management in modern livestock systems.