Effect of age on the dimensions and shape of spermatozoa of Large White Polish boars

Abstract. Studies were conducted on 190 ejaculates collected from 16 Large White Polish boars, 7-8 months old. In order to examine spermatozoa morphology, an ejaculate sample was taken from boar monthly microscopic slides were prepared. In each preparation morphometric measurements were taken of fifteen randomly selected spermatozoa, using a computer image analysis software (Screen Measurement v. 4.1), to determine basic sperm dimensions and morphology parameters. Moreover, evaluation of frequency of spermatozoa morphological abnormalities was made. It was found that boar age was associated with sperm dimensions and shape. As boars grew older, sperm length, width and head area increased. However, young boars, under 11 months old, had slightly longer spermatozoa than older boars, in terms of both the length of the whole spermatozoon and the length of the flagellum. The spermatozoa’s morphological build indicators show that boars aged 16 months approx possess semen that is characterised by an elongated head. This assertion is based on the proportions between the head’s width and its length. This proportion proved to be smaller when compared to that present in the sperm of boars over the age of 17 months (P≤0.01).