Summary. Semen from low-fecundity cocks, characterized by relatively large numbers of spermatozoa with abnormal morphology, poor motility and sluggish metabolism, fertilized very few eggs when inseminated mid-vaginally, but produced moderate fertility when deposited in the uterus.The percentage of pre-ovipositally dead embryos was also increased in eggs fertilized by spermatozoa from low-fecundity cocks when these were deposited directly in the uterus.Few spermatozoa from low-fecundity cocks entered and/or survived in oviducal glands, especially in those of the uterovaginal junction.