Influence of neuraminidase on fertility and on sperm storage in the hen's oviduct.

Preinsemination incubation of semen with neuraminidase (4 IU/2 x 10(9) spermatozoa) significantly reduced fertility in one out of two trials. No differences were observed in fertility between semen treated with 4 versus 8 or 4 versus 16 IU of neuraminidase in Trials 1 or 2. All three levels of neuraminidase (4, 8, or 16 IU) removed the same amount (about 45%) of the bound sialic acids from spermatozoa during incubation. The removal of sialic acid from spermatozoa had a slight but nonsignificant affect on sperm storage within the uterovaginal (UV) sperm-host glands. Hens inseminated with neuraminidase-treated spermatozoa had decreased numbers of full and partially full UV sperm-host glands and increased numbers of empty glands, compared to hens inseminated with untreated but incubated spermatozoa. In the present study, reduced fertility resulting from the treatment of spermatozoa with neuraminidase from Clostridium perfringens indicates the desirability of exploring the use of other neuraminidases to see whether a correlation exists between the amount of sialic acid removed from spermatozoa and their subsequent fertility.