Cryopreservation of stallion sperm in different extenders

Cryopreservation compromises sperm viability and fertility due to the physical and chemical stress placed on cells during freezing. Stallion sperm have low cryopreservation stability. Improving cryopreservation protocols, including extender composition, is essential. This study analyzed the use of two extenders for centrifugation and cryopreservation of stallion sperm. Twenty-seven ejaculates from nine stallions were analyzed. The analysis revealed significant differences (P < 0.05) in motility assessment and the number of intact cells after centrifugation in the different extenders. The experimental extender proved superior. No significant differences were observed in the number of spermatozoa with tail, acrosome, or DNA damage, or in the 2.4 DNF respiration stimulation level. The use of the experimental extender better preserved sperm motility (P˂0.05), morphology (P˂0.01), acrosomes (P˂0.05) and the coupling of respiration and phosphorylation (2.4 DNP test) (P˂0.01) in the selected sperm cryopreservation protocol compared to the LCHZ extender.