Comparison of Egg Yolk and Gum Arabic Extenders With Microencapsulation and α‐Lipoic Acid Supplementation for Canine Semen Cryopreservation

Cryopreservation is an essential component of assisted reproductive technologies in dogs. However, post-thaw semen quality is often compromised by cryo-induced oxidative stress, membrane disruption, and DNA damage, which ultimately reduce fertility outcomes. Conventional egg yolk (EY)-based extenders provide partial protection during freezing but pose biosecurity rick and exhibit batch-to-batch variability. Gum arabic (GA), a plant-derived polysaccharide with cryoprotective and antioxidant properties, has emerged as a potential alternative. The present study evaluated the comparative efficacy of EY and GA extenders, with and without microencapsulation and α-lipoic acid (ALA) supplementation, on post-thaw semen quality in dogs. Semen was collected from six sexually mature Labrador retrievers, with three ejaculates obtained from each dog. Semen samples were cryopreserved in straws under three treatment conditions: extender alone (Treatment 1), extender with microencapsulation (Treatment 2), and extender with microencapsulation plus ALA (Treatment 3). Post-thaw evaluation included sperm motility, viability, acrosomal integrity, hypo-osmotic swelling test (HOST), DNA fragmentation index (DFI), mitochondrial membrane potential (MMP), and total antioxidant capacity (TAC). The results indicated that microencapsulation and ALA supplementation improved several post-thaw sperm quality parameters. Treatment 3 showed the highest values of sperm viability, plasma membrane integrity, acrosomal integrity, MMP, and total antioxidant capacity in both extenders. Sperm motility and DFI did not differ significantly among treatments, although numerically lower DFI values were observed in GA-based treatments. In conclusion, the combined use of GA extender, sperm microencapsulation, and ALA supplementation may enhance the preservation of canine sperm functional integrity during cryopreservation. Further studies evaluating fertility outcomes are required to confirm the practical applicability of these approaches in canine reproductive technologies.