16 FERTILIZING POTENTIAL OF STORED TURKEY SPERM

Abstract

Considerable interest exists in prolonging the viability and duration of the fertilizing capacity of turkey sperm. Commercially available extenders for turkey semen are unable to maintain sperm survival for longer than a few hours and attempts to develop a suitable cryopreservation medium have met with limited success. The objective of the present study was to investigate the use of andrology products designed and optimized for turkey sperm (NidaCon International). In an insemination trial on a commercial turkey farm, semen was collected by abdominal massage and was immediately extended in 4 mL of either Turkey Semen Extend (NidaCon International, Gothenburg, Sweden) or Beltsville (Continental Plastic Corp, Delavan, WI). The extended semen (approximately 20 μL, representing a dose of approximately 70 million sperm) was used immediately for artificial insemination, with each bird being inseminated once weekly. The two groups of birds were housed in different buildings, with different semen donors for each. Eggs were candled after 5 days. Preliminary results showed that fertilization and hatching rates were similar in the two groups: Group 1 (Turkey Semen Extend) 966 eggs, 84.4% fertilized, 78.7% hatched; Group 2 (Beltsville) 966 eggs, 86.6% fertilized, 79% hatched. A second trial over a longer period showed similar results: Group 3 (Turkey Semen Extend) 18,450 eggs, 93.3% fertilized, 84.6% hatched; Group 4 (Beltsville) 40,873 eggs, 92% fertilized, 84.2% hatched. In a second experiment, turkey semen, extended as described above, was transported to the laboratory in the dark at ca. 34°C. Sperm motility was assessed subjectively at several time points. After 2 hours’ storage, at least 50% of the sperm in Turkey Semen Extend were still motile, compared to only approximately 5% of the sperm in Beltsville medium. Aliquots of semen in Turkey Semen Extend were processed by discontinuous density gradient centrifugation on Turkey Gradient (NidaCon International). At least 40% motility was observed after 24 hours’ storage at room temperature. In conclusion, the new Turkey Semen Extender and Turkey Density Gradient offer exciting possibilities for improving the viability of stored turkey sperm for insemination. Future studies will assess the fertility of both unprocessed stored turkey sperm in Turkey Semen Extend, and gradient-prepared stored turkey sperm.