[Autoimmune asthenospermia induced by an epididymal protein, ovine prealbumin (oPES)]

The motility of ejaculated spermatozoa (% of progressive spermatozoa) has been evaluated visually on 26 adult rams. Half the animals were immunized with a secretory epididymal protein (prealbumin epididymal-specific (PES) ovine) injected according to immunizing protocols (Freund or Hunter adjuvant) intraperitoneally or intradermally (Freund or Hunter adjuvant) or intramuscularly (Hunter adjuvant or PES only). The other animals received the same product without the protein (controls). The product resulted in a strong asthenospermia which parallels the transient presence of anti-PES antibodies in the seminal plasma. A study with 64 ewes showed that the fertility of 10 immunized rams that had recovered sufficient forward motility to ensure fertilization, did not differ from that of control rams.