Cryoprotective and Antibacterial Effects of Resveratrol on Frozen-Thawed Turkey Spermatozoa

This study aimed to evaluate the effects of resveratrol (RES) supplementation in the cryopreservation medium on the conventional and non-conventional quality parameters, oxidative status, and microbial profile of cryopreserved turkey semen. Ejaculates (n = 40) were cryopreserved in a modified Beltsville extender either without RES (the cryopreserved control [Ctrl_C]) or with 5, 10, or 25 µM RES . Fresh semen served as a negative control (Ctrl_N). Post-thaw analyses included assessments of motility, viability, membrane functionality, mitochondrial activity, DNA fragmentation, apoptotic status, reactive oxygen species (ROS), protein carbonyl (PC), and malondialdehyde (MDA) levels. Bacteriological analysis was performed using the matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The results obtained indicate that the sperm quality, particularly the mitochondrial activity, was significantly improved following the administration of 5 μM RES compared to Ctrl_C (p < 0.05). All RES doses were particularly effectvive in preventing the ROS overgeneration and associated lipid peroxidation relative to Ctrl_C (p<0.05). The bacterial load decreased in a dose-dependent manner, whereas RES was found effective in enhancing the antibacterial efficacy of gentamicin in the frozen-thawed semen. In conclusion, this study demonstrates that supplementing the modified Beltsville extender with 5 or 10 µM RES improves post-thaw turkey semen quality.