Duration of fertility of turkeys inseminated at different times after the onset of photostimulation.

To investigate the relationship between photostimulation, ovary and oviduct weights, and oviductal sperm-storage tubule (SST) development and functional capacity, 33-week-old turkey hens were placed in four groups of 15 hens each. Each group was inseminated three times in 30 min with 50 x 10(6) spermatozoa (a total of 150 x 10(6) spermatozoa) on the day of photostimulation, or on Days 7, 14, or 21 after the onset of photostimulation (Groups A, B, C and D, respectively). From weeks 4 to 8 after photostimulation, 5 additional hens were inseminated each week and then killed 24 h later to determine ovary and oviduct weights and SST status. Regardless of ovary and oviduct weights and insemination times in relation to photostimulation, 76 of 78 hens possessed morphologically differentiated SST, and 73 of the 76 hens had some SST which contained spermatozoa. For Groups A, B, C and D, the duration of fertility was approximately 7-8 weeks. It is concluded that morphologically differentiated SST are functional in 33-week-old hens regardless of the status of the ovary and oviduct.