Sterile boars with ‘knobbed’ spermatozoa

Abstract

Investigations have been made of boars yielding spermatozoa with a specific morphological (‘knobbed’) defect of the acrosome.Counts were made of the number of knobbed spermatozoa in pairs of nigrosin eosin smears made from the semen of normal boars, in the semen of two (‘affected’) full brothers with ejaculates known to contain a high proportion of knobbed spermatozoa, and in mixtures of normal and affected ejaculates. Few or no knobbed spermatozoa were recorded in the semen of normal boars. Virtually all spermatozoa from the affected boars were recorded as knobbed. Counts on mixed samples agreed well with expected values.