SEMINAL PLASMA ZINC CONCENTRATION IN RELATION TO SPERM QUALITY PARAMETERS IN BOARS

Abstract Zinc plays an important role in pig reproduction and is associated with boar sperm quality or quantity parameters. The aim of this study was to evaluate a relation between boar sperm quality parameters and seminal plasma zinc concentration. Thirty-eight ejaculates from thirty-eight boars from one AI centre were used in this study. The following semen quality and quantity parameters were evaluated: morphologically abnormal spermatozoa (MAS), sperm motility, semen volume, sperm concentration and total number of spermatozoa per ejaculate. Only non-significant differences were found among the groups in the MAS incidence and in the boar sperm motility parameter. The highest MAS incidence (24.3 %) was found in group with the lowest seminal plasma zinc concentration while the lowest MAS incidence (16.8 %) was noted in group with the highest seminal plasma zinc concentration. On the basis of these results we cannot conclude that there is a significant relation between boar seminal plasma zinc concentration and evaluated sperm quality parameters. Key Words: Zinc, seminal plasma, boar Seminal plasma is important for progresive motility of sperm cells (Rodriquez-Martinez et al., 1990) and might be of importance to protect membranes and maintain fertilizing capacity during storage (Harrison et al., 1978). Sperm function is highly dependent on ionic environment The aim of this study was to evaluate a relation between boar sperm quality parameters and seminal plasma zinc concentration. Material and Methods Thirty-eight ejaculates from thirty-eight boars from one AI centre were used in this study. The following semen quality and quantity parameters were evaluated: morphologically abnormal spermatozoa (MAS), sperm motility, semen volume, sperm concentration and total number of spermatozoa per ejaculate. MAS incidence were evaluated microscopically under oil immersion and 1500x magnification according to the staining method of Čeřovský (1976). Sperm motility was evaluated subjectively by microscopic estimation of the number of sperm moving in a visual field of phase contrast microscopy with a heating stage (38°C) at 100x magnification. Each sample was examined at three different microscopic fields and motility was expressed as percentage of sperm showing normal forward progressive movements. Sperm concentration was estimated using a Bürker counting chamber. Sperm samples were centrifuged and seminal plasma was removed for zinc concentration analyzes. Results were divided in three groups based on zinc concentration. Group I up to 450 umol/l (n = 15). Group II between 450 to 600 umol/l (n = 12). Group III over 600 umol/l (n = 11). Statistical characteristics of the results were calculated using the QC Expert statistical program. Statistical significance was checked by the analysis of variance ANOVA. Results and Discussion Figure 1 shows differences in the MAS incidence in comparison to the seminal plasma zinc concentration. The highest MAS incidence was found in group I (24.3 %) while lower MAS incidence was noted in group II (22.5 %) and group III (16.8 %). There is a possibility to conclude that seminal plasma zinc concentration related to a certain degree to MAS incidence. However it's necessary to say that no significant differences in the MAS incidence were found among the groups. Furthermore only low non-significant correlation between zinc concentration and MAS incidence (r = -0.13) was noted. In boars it has been shown that, when sperm cells are damaged, Zn accumulates in the sperm cells with a consequent reduction of Zn in seminal plasma Sperm motility was the second sperm quality parameter evaluated in this experiment. There were only minimal and non-significant differences among the groups in this parameter. The highest average motility was observed in group II. (62.1 %) while the lowest average motility (56.7 %) was observed in the group with the lowest seminal plasma zinc concentration. The results for average sperm motilit