Abstract
Serum samples collected from selected swine breeding farms in St.Paul, Minnesota, U.S.A. were screened for zona pellucida (ZP) antibodies by the Enzyme-linked immunosorbent Assay (ELISA) technique. Of the 1865 samples screened, 107, 171, 489, 329, 302 were in the age ranges 0-6, 7-12, 13-18, 19-24, 25-30 and above 30 months of age and the proportions positive for ZP antibodies were 0, 5.26, 9.61, 14.78, 18.84 and 19.21% respectively. A total of 245 (13.14%) of them positive for ZP antibodies and seropositivity increased with age (P<0,001). The farm of origin was not associated with the presence of antibody (P>0.10) and there was no interaction between farm of origin and age of animal (P>0.10). The possibility of gential infections contributing to the auto-immunity cannot be ruled out and the association of the antibodies with increased age may be due to infections over a long time. This aspect of immunological infertility should be taken into consideration when investigating infertility in swine herds.
(Tropical Veterinarian: 2003 21(1): 42-46)