Standardizing insemination interval for turkey hens with diluted semen preserved at 5 °C for optimum fertility

Standardizing insemination interval with liquid stored semen is necessary for better application of assisted reproductive biotechnology for genetic improvement in turkey. This experiment was designed to identify appropriate insemination intervals to achieve optimum fertility with tom semen preserved with Tris Egg-yolk Orange (TEYO) extender for 4 and 12 hours at 5 °C. Five healthy indigenous toms and ninety six hens of 38 weeks of age were used for this study. A 4x2 factorial design with two insemination frequencies and four types of semen was employed in a completely Randomized Design. The four varieties of semen used were undiluted, TEYO diluted, 4 hours TEYO chilled, and 12 hours TEYO chilled. The second factor is once or twice weekly insemination frequencies. The results showed that turkey hens inseminated with 12 h TEYO chilled semen had significantly lower fertility rates, hatchability of viable eggs, and egg sets than those inseminated with 4 h TEYO chilled semen, TEYO extended semen, and un-extended sperm. The value for 4 hours of TEYO chilled semen, however, did not differ appreciably from the un-chilled semen value. The results showed that twice per week insemination had significantly higher percentage fertility value compared to once per week insemination for un- chilled and 12 h TEYO chilled semen. The results revealed that once per week insemination had a higher hatchability percentage of fertile eggs for 4 h TEYO chilled semen, TEYO extended semen, and un-extended semen compared to twice per-week insemination. The results revealed that once per week insemination had a higher hatchability percentage of eggs set compared to twice per week insemination for 4 h TEYO chilled tom semen. The results revealed that only in un-extended semen and 4 h TEYO chilled semen dead-in-shells were recorded. It was therefore concluded that twice per week insemination interval indicated better fertility and hatchability results for 12 h TEYO chilled turkey semen, while once per week insemination gave a better fertility and hatchability result for 4 h TEYO chilled turkey semen.