The spermatogenesis is markedly affected in SA boars. A. In the testis cross sections of SA affected boars no spermiogenic cells are present and increased vacuolization can be seen compared to the control testis. B. Clear reduction in the amount of spermatogonia and spermatocytes in SA affected animals can be seen compared to control animals. No spermatids are present in the testis of SA boars. The number of germ cells is compared to the amount of Sertoli cells.