Gamboa, S., Quaresma, A., Castro, F., Bravo, P., Rebordão, M.R., Oom, M.M. & Rocha, A. (2017) In vivo fertilizing ability of stallion spermatozoa processed by single layer centrifugation with Androcoll-ETM.Saudi Journal of Biological Sciences, Online early, . DOI:10.1016/j.sjbs.2016.01.030 (IF2016 2,564; Q2 Biology)
A colloid with a species specific silane-coated, silica-based formulation, optimized for stallion (Androcoll-ETM), enables a better sub-population of spermatozoa to be selected from stallion ejaculates. However, such practice has not been critically evaluated in stallions with fertility problems. In this study we evaluate whether single-layer centrifugation (SLC) through Androcoll-ETM could be used to enhance fertility rates in a subfertile stallion. Ejaculates were obtained from two different stallions, one Lusitano (fertile) and one Sorraia (subfertile), with distinct sperm characteristics and fertility. Motility, morphology, plasma membrane structural (eosin-nigrosin) and functional integrity (HOS test), mitochondrial functionality (Δψm; JC-1) and longevity (motility after 72h cooling) after centrifugation in Androcoll-E™, as well as pregnancy rates obtained after artificial insemination (AI), with and without (control group) SLC-treated sperm were assessed. The effect of SLC on sperm characteristics, and fertility results were evaluated by ANOVA and Fisher procedures, respectively. Our results showed that SLC-selected sperm did not differ from the raw semen in terms of viability, morphology, response to hypo-osmotic conditions (HOS test) and mitochondrial membrane potential (↑ΔΨmit; JC-1). Sperm motility in cooled samples was not improved by SLC treatment. Our data show that SLC through Androcoll-ETM has no effect on pregnancy rates in the stallions used in this trial.