Normal fertility in ewes after cervical insemination with frozen-thawed spermatozoa supplemented with seminal plasma

The effect of seminal plasma (SP) on the motility, capacitation status, pen etration through cervical mucus and fertility of frozen-thawed ram spermato zoa was examined. Ln the presence of SP, motility of frozen-thawed spermato zoa was better (P<0.001) and there were more uncapacitated and less acrosom e-reacted cells in comparison with controls (P<0.001). Frozen-thawed sperma tozoa were also better able to penetrate cervical mucus after addition of S P. Addition of SP increased the percentage of ewes pregnant after inseminat ion of frozen-thawed (39/94, 41.5% v. 51/92, 55.4%; P<0.05) but not fresh s permatozoa (34/55, 61.8% v. 42/58, 72.4% for 0 v. 30% SP in the resuspensio n medium). Moreover, SP improved pregnancy rates after cervical (14/50; 28% v. 25/49; 51%; P<0.05) but not intrauterine insemination (25/44; 56.8 v. 2 6/43; 60.5%) with frozen-thawed spermatozoa. In a second experiment, pregna ncy rates were 30/45 (66.7%), 9/37 (24.3%) and 24/40 (60.0%) for ewes insem inated with frozen-thawed spermatozoa in the uterus (control), cervix witho ut SP and cervix after supplementation with SP, respectively (P<0.01 for un supplemented v. supplemented spermatozoa). These experiments demonstrate th at impaired function of cryopreserved spermatozoa can be overcome by additi on of SP, resulting in normal fertility after cervical AI.