Kinematic parameters of thawed ram semen frozen under field conditions were analysed with the use of two commercial (egg yolk vs egg yolk free) semen extenders in different year-seasonal periods. The semen was collected from Suffolk (n = 2) and Charollais (n = 1) rams kept in private breeding farm on 3 test days (pre-mating, at mating, post mating) during year 2016. Two commercial semen extenders (egg yolk-based BullXcell® or egg yolk-free AndroMed®) were used for semen processing. Processed semen was frozen in 0.25 ml plastic cryostraws using the custom-made portable freezing box for ram semen cryopreservation under field conditions. Thawed semen characteristics were evaluated using computer-assisted semen analysis (CASA) system immediately after thawing and after 2 h of heat incubation (±38°C). Significantly higher total motility (+12.3%), straight line velocity (+5.6 µm s–1), and average-path velocity (+6.9 µm s–1) were detected for the semen processed and cryopreserved using egg yolk-based semen extender. Year-seasonal variation and introducing the ram to service had shown to have a significant effect on the cryopreserved ram spermatozoa. These preliminary results confirmed the feasibility of ram semen processing and cryopreservation under field conditions.
spermatozoa, AndroMed®, BullXcell®, freezing box, CASA
Ptáček, M., Stádníková, M., Savvulidi, F., Stádník, L. (2019): Ram Semen Cryopreservation Using Egg Yolk or Egg Yolk -Free Extenders: Preliminary Results. Scientia Agriculturae Bohemica, 50, 96-103. DOI: 10.2478/sab-2019-0014