An Examination for Sperm Capacitation in the Fowl

TLDR: None of 10 ova recovered from unmated hens showed signs of development after culture under the same conditions but without incubation with spermatozoa, providing direct evidence that avian spermatoza do not require a period of capacitation within the hen's reproductive tract in order to fertilize ova.

Abstract: The in vitro culture system developed was capable of supporting recently ovulated chicken ova in a viable state for at least 24 hr. Utilizing this system, 8 out of 10 ova obtained from the body cavity or infundibulum of unmated White Leghorn hens, were successfully fertilized in vitro. Microscopic examination of the eight fertile blastodiscs revealed that five had proceeded to the blastula state of development during the 24-hr culture period. The remaining three fertile ova, apparently retarded, had not progressed beyond the early cleavage stage of development. None of 10 ova recovered from unmated hens showed signs of development after culture under the same conditions but without incubation with spermatozoa. These observations afford direct evidence that avian spermatozoa do not require a period of capacitation within the hen’s reproductive tract in order to fertilize ova.