Characteristic of selected rheological parameters of stallion ejaculate

Abstract. Dynamic viscosity of native (30 minutes after ejaculation) and 24 hours stored (at 4 °C) stallion ejaculate was measured. The ejaculate from 10 breeding stallions was examined in three different experimental series. The average value of dynamic viscosity at shear rate 1.02 s⁻¹ was found to be 416.8 ± 10.1 mPa.s. The correlation between ejaculate volume, sperm concentration and viscosity was tested. The experiments resulted in finding a dependence between increasing viscosity and decreasing sperm concentration (r_p = −0.67; P<0.05). Performed experiments with changing shear rate demonstrated non-Newtonian characteristics of stallion ejaculate with a clear shear-thinning behaviour. Stallion ejaculate appeared to be slightly time-dependent liquid.