Metabolic Profile in Dairy Cows With Cystic Ovarian Follicles: A Systematic and Meta-Analysis of Available Evidence from USA, Iran, and Indonesia

Cystic ovarian follicles (COF) are a major reproductive disorder in dairy cows associated with metabolic imbalance and reduced fertility. This systematic review and meta-analysis aimed to synthesize evidence on serum metabolic biomarkers in cows with COF compared to healthy controls and to explore cross-country variability. A comprehensive search of PubMed, Scopus, and Web of Science up to December 2023 identified three eligible studies from the United States, Iran, and Indonesia. Included biomarkers were non-esterified fatty acids (NEFA), β-hydroxybutyrate (BHBA), blood urea nitrogen (BUN), insulin, and cortisol. Standardized mean differences (SMDs) were calculated for each study and pooled using a random-effects model. The overall pooled estimate was not statistically significant (SMD=−0.302; 95% CI −6.867 to 6.264; p=0.928), and heterogeneity was extremely high (I²=99.31%). Subgroup analysis showed contrasting patterns by country: neutral in the United States, positive in Iran, and negative in Indonesia. Sensitivity analysis focusing on NEFA supported the primary findings. The observed discrepancies may reflect differences in production systems, nutritional management, heat stress, and diagnostic criteria. This research aligns with Sustainable Development Goals (SDGs) 2 (Zero Hunger) and 3 (Good Health and Wellbeing), supporting improvements in livestock productivity and animal health.