Association of Ejaculate Sperm Counts with their Morphological and Morphometric Characteristics in Hypor Boars

Reproductive efficiency in pigs is largely dependent on the fertility of the boar. Boars used at insemination stations should produce a large amount of semen with high fertilization capacity. The sperm count influences the conception rate and the number of insemination doses produced. The aim of this study was to evaluate the morphological and morphometric characteristics of boars of the Hypor breed in relation to the total sperm count in the ejaculate. An analysis was performed of 120 ejaculates collected from 12 Hypor boars used at three insemination stations. The ejaculate sperm count was found to affect the morphometric characteristics of spermatozoa from boars. In the ejaculates with the lowest sperm count the spermatozoa heads were significantly shorter and narrower and had a smaller surface area. The sperm from ejaculates with the lowest sperm count had relatively small head dimensions in relation to the tail length and total sperm length. In the ejaculates with the most sperm cells, the proportion of spermatozoa with major defects was significantly greater than in the ejaculates from other groups. In the ejaculates with the lowest sperm count the frequency of sperm with progressive motility was significantly lower. The fewest insemination doses can be prepared from these ejaculates.