Optimizing in vitro embryo production in cattle: strategies for donor management and selection.

Abstract

In vitro embryo production (IVEP) has become a cornerstone of genetic advancement in cattle, yet its efficiency remains suboptimal and highly variable. This review synthesizes current knowledge on donor selection and management strategies aimed at optimizing IVEP outcomes. Central to IVEP success is the quantity and developmental competence of oocytes, which is influenced by both intrinsic donor characteristics and extrinsic management interventions. Ovarian superstimulation using follicle-stimulating hormone (FSH) has emerged as a key strategy to enhance oocyte yield and quality, with evidence supporting dose-dependent improvements in embryo development and yield. Protocol refinements-including timing, duration, and delivery mode of FSH- can further influence IVEP efficacy. Donor-specific factors such as age, pregnancy status, and size of the ovarian reserve, assessed via antral follicle count (AFC) or anti-Müllerian hormone (AMH) concentrations, significantly affect oocyte competence and/or embryo yield. Additionally, newly developed genomic traits and selection indexes, offer predictive value for donor performance and enable integration of IVEP-specific traits into breeding programs. High AMH donors consistently outperform low AMH counterparts, and emerging evidence suggests that tailoring superstimulation protocols to AMH phenotype can further enhance IVEP outcomes. The integration of physiological and genomic data provides the opportunity for developing targeted, phenotype/genotype-driven superstimulation protocols to maximize IVEP efficiency in a cost-effective and biologically sound manner.