Single layer centrifugation improves the quality of frozen-thawed sperm of giant panda (Ailuropoda melanoleuca)

The reproductive capacity of captive giant pandas is poor and sperm cryopreservation is necessary for the reproduction and conservation of this species. Cryopreservation, however, leads to a significant decrease in sperm quality, including sperm motility, acrosome integrity and DNA integrity. In the present study, a method was developed based on colloid single layer centrifugation that could significantly improve frozen-thawed sperm quality. Two colloids were compared for post-thaw giant panda sperm preparation; the sperm samples had greater total motility (Colloid 1: 44.5 ± 16.0%, Colloid 2: 42.4 ± 10.1% compared with Control: 25.4 ± 8.4%, P < 0.05), linear velocity (Colloid 1: 17.2 ± 8.3 μm/s; Colloid 2: 19.0 ± 9.0 μm/s compared with Control: 6.6 ± 1.7 μm/s, P < 0.05) and membrane integrity (Colloid: 46.9 ± 13.2%; Colloid 2: 54.3 ± 5.7% compared with Control: 36.0 ± 9.1%; P < 0.05). This method could be a useful tool to enable the use of poor quality sperm samples and benefit this population by using available genetic material.