Establishing a Semen Cryobank for Yan Goose: Optimized Collection and Cryopreservation

Yan goose, a representative Chinese local breed, requires genetic resource conservation. To address this, we optimized a semen cryopreservation protocol for Yan geese and validated its feasibility in large-scale cryobank production. Using motility of frozen-thawed sperm (MFS) as the primary indicator, supplemented by artificial insemination (AI) trials, we systematically evaluated cryoprotectant type, freezing rate, extender osmolality and pH, and thawing rate. Dimethylformamide (DMF) significantly outperformed dimethylacetamide (DMA) in MFS (34.17% vs. 24.17%, p < 0.05). Based on optimization data and practical requirements, the final DMF method comprised freezing at 2.0 cm above liquid nitrogen for 2 min, extender osmolality of 335 mOsm/kg at pH 7.8, and thawing at 5 °C for 60 s. Teaser-induced semen collection was successfully applied in a Chinese local goose breed for the first time, achieving a 69.14% success rate. Using this system, production over 17 days yielded 1225 straws (96.61% qualified), of which 838 from 30 families were banked. AI of banked semen achieved a fertilization rate of 70.4% and a hatchability of 86.8%. These findings demonstrate the successful establishment of a cost-effective cryobank for Yan geese, providing a feasible paradigm for conserving other Chinese local goose breeds.