Metabolic and deficiency disorders, body condition, and efficiency in assisted bovine reproduction

Abstract

The objective of this review was to evaluate how metabolic disorders, nutritional deficiencies and body condition status (BCS) influence the efficiency of bovine assisted reproduction; for this purpose, a narrative systematic review was conducted between January 2000 and March 2025 in PubMed, Scopus, Web of Science and SciELO, selecting 83 original studies that met strict criteria for objective measurement of BCS and metabolic parameters (BEN, ketosis, hypocalcemia, selenium, zinc, phosphorus and antioxidant deficiencies). The inclusion criteria were: embryos, conception, transfer, stress, metabolism and fertility. The findings reveal that negative energy balance and mineral deficiencies induce neuroendocrine alterations (GnRH/LH suppression, decreased IGF-1, and leptin resistance), systemic oxidative stress, and non-viable follicular and uterine microenvironments, which reduce pregnancy rates by up to 40% in cows with ECC < 2.5 (scale 1–5), even under optimal hormonal protocols. The moderate heritability of ECC and its evaluation with production and fertility support its use as a genetic selection trait. Consequently, the efficiency of ART does not depend on hormonal optimization but on the prior correction of metabolic status. Therefore, the evaluation of ECC and serum metabolic profiles should be implemented as a mandatory pre-reproductive screening protocol. Targeted nutritional interventions during the peripartum period are essential to transform assisted reproduction into a reliable, cost-effective, and sustainable tool in low-resource systems.