Effect of sperm numbers per insemination following early or late initial inseminations in turkeys.

Large White turkey hens were used in this study to investigate sperm storage in the hen throughout a 20-week breeding cycle. Hens were initially inseminated early or late and subsequently at 7-day intervals with either 20, 50, or 100 million sperm each time. Early inseminations (EI) were performed on Days 14 and 17 postlighting, and the late inseminations (LI) were performed on Days 21 and 24 postlighting. Fertility (percent) was calculated weekly for 20 weeks following the second initial insemination in each group. Fertility was greatest in EI hens for the 20-week period; the largest difference occurred between EI and LI treatments of the 50 million sperm/insemination group. A significant interaction was observed between time of initial insemination and sperm numbers per insemination. Overall fertility was improved with each increase in sperm numbers/insemination.