Effect of seminal plasma addition from high and low fertility animals on the cryopreservation of epididymal tail and ejaculated sperm from subfertile stallions

The aim of this study was to compare the effect of the addition of seminal plasma from high and low fertility stallions on sperm viability offrozen-thawed sperm cells from ejaculate and from epididymal tail of subfertile stallions. Six stallions with a history of subfertility were used. After collection, ejaculate spermatozoa were divided into three aliquots: Botu-Semen (R) (EJ-CT); High-quality seminal plasma (EJ-PS1); Low-quality seminal plasma (EJ-PS2). The same was done with sperm cells from epididymis tail after orchiectomy (EP-CT; EP-PS1; EP-PS2). Evaluations of sperm kinetics were assessed by CASA and membrane and acrosome integrity, DNA fragmentation, sperm capacitation and sperm peroxidation were assessed by flow cytometry. After thawing, no differences were observed between ejaculated sperm (EJ) and epididymal sperm (EP) in any CASA evaluations. However, higher (P< 0.05) percentage of cells with intact plasma and acrossomal membranes was observed in EP groups (EP-CT:31.7 +/- 7.5b; EP-PS1:35.2 +/- 7.0b; EP-P52:33.9 +/- 7.2b) compared to EJ groups (EJ-CT: 15.1 +/- 4.9a, EJ-PS1: 11.7 +/- 4.5a, EJ-P52: 13.1 +/- 5,2a). In addition, differences in DNA fragmentation index were observed (EJ-CT:2.6 +/- 0.6a; EJ-PS1:2.4 +/- 0.8a; EJ-PS2:3.0 +/- 0.8a; CT: 1.4 +/- 0.4b; EPPS]: 1.2 +/- 0.3b; EP-1'52: 1.3 +/- 0.2b). It was concluded that the addition of 20% seminal plasma from fertile or subfertile animals prior to the freezing of epididymal spermatozoa from subfertile animals does not interfere in sperm quality.