Heterogeneidad del eyaculado y criotolerancia para optimizar la reproducción asistida en especies ganaderas y silvestres

Abstract

The fertility of breeding males is a key variable for the sustainability of livestock systems, genetic improvement programs, and the ex-situ conservation of zoogenetic resources. Over the past two years, Animal Reproduction Laboratory (AndroTEC) has drafted eight original articles covering topics ranging from short-term semen storage to the effects of cryopreservation and the dynamics of sperm subpopulations. This article critically integrates those findings. It synthesizes: intrinsic factors (e.g., age, sperm competitiveness) and extrinsic factors (e.g., dilution, storage time) that modulate fresh semen quality; structural and functional alterations induced by cryopreservation in boars, dairy bulls, and alpacas; the usefulness of CASA (Computer-Assisted Semen Analysis) systems and multivariate analyses to understand the distribution of kinematic and morphometric sperm subpopulations
within the ejaculate; and practical implications for artificial insemination, sire selection, and biobank development. Methodological challenges, protocol standardization, and the need for biochemical kinematic integrative approaches are discussed. Future directions include the incorporation of machine learning algorithms and the functional assessment of in vitro defined sperm subpopulations as a step toward “precision andrology.”