Abstract: The objective of the present study was to assess the effects of Astragalus polysaccharides on cryopreservation of semen collected from adventive boars and provide a theorectical reference to improve the formula of diluents for boar semen cryopreservation. Semen was collected from three kinds of American-derived boars (Landrace, Large Yorkshire, Duroc) and diluted in solution supplimented with different concentrations of Astragalus polysaccharides (0, 0.01%, 0.02%, 0.03%, 0.04%, 0.05%, 0.06%). After being loaded into 0.25 mL straws the extended semen was freezed. Subsequently the qualitative parameters (motility, abnormality and acrosomal integrity) of frozen-thawed spermatozoa were estimated, and comparisons of mean values among three breeds of boar at the same conoentration or among treatments at the same breed of boar were performed. The results showed that,when compared without Astragalus polysaccharides acrosomal integrity of frozen-thawed Duroc boar spermatozoa was significantly higher than that of frozen-thawed Large Yorkshire boar spermatozoa (P<0.05), but no significant differences were observed when other comparisions were carried out at the same concentration (P>0.05). Of all the three breeds of boar, 0.04% was the optimal concentration of Astragalus polysaccharides supplied to semen diluents, at which the quality of frozen-thawed semen was significantly better than that of the control (P<0.05). There weren't significant differences in the quality of frozen-thawed semen among the three breeds of boar at the optimal concentration of added Astragalus polysaccharides (P>0.05). In brief, the extender supplimented with 0.04% Astragalus polysaccharides can demonstrate desirable parameters of frozen-thawed spermatozoa in all the three breeds of boar.

Key words: boar; semen; cryopreservation; Astragalus polysaccharides