REVIEW METHODOLOGY

Study design and review approach

This study was conducted as a narrative, integrative review to synthesize current scientific evidence on delayed ovulation in cattle, with a particular focus on its physiological mechanisms, etiological and risk factors, diagnostic approaches, clinical manifestations, and management strategies. An integrative approach was selected to incorporate evidence from diverse research methodologies, including experimental and observational studies, clinical trials, and applied field research.

The review was designed to integrate knowledge from multiple disciplines, including reproductive physiology, endocrinology, nutrition, animal management, and veterinary clinical science, in order to provide a comprehensive and practice-oriented perspective. Rather than performing a quantitative meta-analysis, this narrative synthesis emphasizes biological plausibility, clinical relevance, and applicability across different production systems (dairy and beef cattle). This approach is appropriate given the heterogeneity of study designs, outcome measures, and management contexts reported in the literature on delayed ovulation.

Literature search strategy

A structured literature search was conducted using major scientific databases, including PubMed, Scopus, and Web of Science, supplemented by Google Scholar to capture relevant gray literature and highly cited publications. The search covered articles published between 2000 and 2025, reflecting both foundational studies and recent advances in reproductive management and diagnostic technologies.

Search terms were used in various combinations and included: “delayed ovulation,” “ovulatory disorders,” “follicular persistence,” “LH surge,” “postpartum ovulation,” “cattle reproduction,” “dairy cows,” “beef cattle,” “negative energy balance,” “endocrine disorders,” and “reproductive management.” Boolean operators were applied to refine the search and ensure comprehensive coverage of relevant topics.

Study selection and data synthesis

Articles were screened based on their relevance to delayed ovulation in cattle, with inclusion criteria encompassing studies that addressed at least one of the following aspects: (i) physiological regulation of ovulation, (ii) nutritional, environmental, animal-related, endocrine, or infectious risk factors, (iii) diagnostic tools and criteria for ovulatory disorders, or (iv) management and therapeutic interventions aimed at improving ovulation timing and fertility.

Only peer-reviewed articles published in English were included. Studies focusing exclusively on other species or on reproductive disorders unrelated to ovulatory timing were excluded. After initial screening of titles and abstracts, full-text articles were reviewed to extract relevant data and conceptual insights.

Findings were synthesized narratively and organized thematically to highlight mechanistic pathways, clinical implications, diagnostic challenges, and management decision points. Particular attention was given to identifying knowledge gaps, inconsistencies among studies, and areas requiring further research to inform both clinical practice and future investigative priorities.