Influence of seminal plasma derived from the rich fraction of the ejaculate on the structural characteristics and the kinetics of the swine sperm stored under refrigeration at 17°C for 72 hours

The present study aimed to evaluate the effects of seminal plasma, from the rich fraction of the ejaculate, on kinetics, plasma and acrosome membrane integrity, lipid peroxidation and capacitation of extended liquid boar semen stored under refrigeration at 17° C for 72 hours. For this purpose, four ejaculates from each of six boars were used. Shortly after collection and raw semen evaluation, ejaculates were extended in BTS medium and then assigned to one of three treatments, as follows: non-washed seminal plasma (NWSP), washed-seminal plasma (WSP) centrifuged with own seminal plasma suspended (CWSSP). All treatments were evaluated for sperm motility parameters by the sperm class analyzer (SCA). Plasma and acrosome membrane integrity, lipid peroxidation and sperm capacitation were evaluated by flow cytometry at 0, 24, 48 and 72 hours post dilution. The mean percentage of sperm motility (total and progressive) were lower (p<0.05) in the WSP treatment. There was an increase (p<0.05) in the percentage of sperm with damaged acrosome and damage plasma membrane in the WSP treatment. Membrane lipid peroxidation did not differ (p>0.05) irrespective of treatment nor did sperm capacitation, which was similar (p>0.05) among treatments. Our results show that seminal plasma from the sperm rich fraction is important to maintain adequate structural and functional characteristics of extended liquid boar and should be present in seminal doses throughout the period of store (AU)