Changes in boar semen with a high and low level of morphologically abnormal spermatozoa

Abstract

Some shape abnormalities of spermatozoa (AS) can be a result of pathological processes that affect testicles and the epididymis tract, others can be caused genetically. Some may be caused by unsuitable rearing conditions. Some authors of the papers published in this field consider the level of AS occurrence to be an important marker for the semen quality besides the sperm motility (Leidl et al. According to Waberski et al. (1990) two criteria are sufficient for the selection of boars for insemina-tion or ejaculate: sperm motility and percentage of AS, especially when the semen is preserved and used for the insemination of sows after a longer time, i.e. three to five days. Larsson et al. (1988) considered the motility and morphology of sper-matozoa to be the most sensitive indicators of the heat stress of boars. Malmgren (1989) attributed a ABSTRACT: The aim of the paper was to find out the level of changes in the sperm quality in two groups of boars in the insemination (A and B) with diametrically different contents of morphologically abnormal spermatozoa (AS) with an interval of 25 weeks between semen collection I and collection II. In the group A there were 22 boars with the AS content up to 10%, in the group B 16 of boars with the AS content above 40% in collection I. Both groups were comparable concerning the parameters of the performance test results and in quantitative parameters of the semen from collection I. They differed significantly in the AS content (P < 0.01) and in the age (P < 0.05). In collection II in both groups the semen volume increased significantly (A-P < 0.01; B-P < 0.05), in the group A the number of spermatozoa per ejaculate and per day also increased (P < 0.01). In the group B there was an insignificant clear decrease in the sperm concentration (P > 0.05). In comparison with the group B the group A can be characterized as a group with significantly higher dynamics in the sperm production per ejaculate. An opposite trend was noted in the total AS content. In the group A there was a significant increase (P < 0.001) and in the group B a significant decrease (P < 0.001) in collection II. In the group A there was a deterioration of the AS content in 7 boars (31.8%), in the group B an improvement in 7 boars (43.7%). Particular monitored AS forms are given. A significant difference in the total AS content between both groups was in favour of the group A (P < 0.001). While no boars from the group A exceeded the limit in the AS content for the applicability of semen for insemination (in the Czech Republic 25%), in the group B they remained above this limit without applicability possibility. The detected variations and prevailing stability in the AS occurrence in boars kept in the same conditions lead us to a consideration of hereditary characteristics of the spermatogenesis factor, of considerable persistence of the level of monitored characteristics and to a consideration of applicability of the phenotype AS presentation to selection of boars for artificial insemination.