A Comparative Study on the Efficacy of Four Semen Extenders and Thawing by Seminal Plasma on the Quality of Frozenthawed Boar Semen

The present study investigated the influence of four different commercial semen extenders used during theholding time and the use of seminal plasma as a thawing medium on the frozen-thawed (FT) boar semen quality.Sperm-rich fractions were collected from 11 boars and were divided into four groups according to the type of semenextender used during the holding time (A, B, C and D). The extended semen was cooled down and centrifuged. Thesperm pellets were diluted in lactose-egg yolk extender plus glycerol and Equex STM Paste. The semen were loadedinto 0.5 ml straws and frozen. Thawing was achieved by immersing the straws in 500C water for 12 sec. The semenwas divided into two groups: the control group was diluted in BTS; the treatment group was diluted in seminalplasma. The post-thawed sperm qualities including subjective motility, sperm viability, functional integrity of thesperm plasma membrane and acrosome integrity were evaluated. It was found that semen extended in extender D for2 hours before cryopreservation yielded a higher individual motility than those extended in extender B (20.9% and16.9%, p= 0.045) and tended to be higher than those extended in extender A (17.5%, p= 0.090). Thawing ofcryopreserved boar semen in BTS yielded a significantly higher subjective motility than thawing in seminal plasma(20.3% and 16.9%, p= 0.021). It could be concluded that both types of extender used during the holding time and thethawing medium significantly influenced FT boar sperm quality.