Frequency of Cytoplasmic Droplets Depends on the Breed and Age of Insemination Boars.

In this study an attempt was made to analyse morphological changes in sperm with particular attention to sperm with a cytoplasmic droplet, taking into account the age and breed of the boar. The material for the study consisted of ejaculates of insemination boars of five breeds. Morphological examination of sperm was carried out in 30 randomly selected boars--6 individuals from each breed. The morphology of 500 spermatozoa was evaluated in each slide. The percentage of sperm with normal morphology in the semen of the boars varied between breeds and was dependent in varying degrees on the age of the boar. The primary defects in sperm occurred more frequently in Duroc and Pietrain boars than in other breeds and were more dependent on the age of the boar. The high percentage of primary defects in the sperm of young Duroc boars was determined by the frequency of sperm cells with a proximal cytoplasmic droplet on the midpiece. A particularly high percentage of sperm cells with secondary defects was noted in the initial stage of the reproductive life of the boars. The high number of sperm cells with secondary defects noted in the semen of the Duroc and Pietrain boars and the changes occurring with age in the frequency of secondary morphological defects were mainly determined by the frequency of sperm cells with a distal protoplasmic droplet in the middle piece and to a lesser degree by that of sperm cells with a pseudodroplet.