The effect of antioxidant supplementation in semen extenders on semen quality and lipid peroxidation of chilled bull spermatozoa

Document Type : Short paper


1 Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran

2 Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran


The aim of this study was to determine the effects of the antioxidants superoxide dismutase (SOD),
glutathione peroxidase (GPx) and butylated hydroxytoluene (BHT) on microscopic semen parameters and
lipid peroxidation following the freeze-thawing of bull semen. Ejaculates were collected from five Holstein
bulls and pooled at 37°C. The semen samples were diluted with a CEY extender containing additives
including 100 U and 200 U SOD/ml, 50 U or 100 U GPx/ml and an extender containing no antioxidants
(control) and stored in liquid nitrogen. The pooled ejaculates were then diluted with CEY or a Tris
(hydroxymethyl) aminomethane (TRIS)-based extender (TEY) alone or with added 0.5, 1.0, 2.0 or 4.0 mM
BHT, and the routine semen evaluation was conducted. The lowest production of malondialdehyde (MDA)
was obtained by addition of 100 U SOD/ml, 0.5 and 1 mM BHT to CEY extender compared with the other
groups. Sperm viability and motility was significantly higher when 0.5, 1 mM BHT and 100 U SOD/ml were
added in CEY extender. The highest sperm viability was achieved by addition of 50 U GPx/ml to CEY
extender. In addition, sperm motility was significantly higher in samples extended in Tris-egg yolk (TEY)
with 0.5 mM BHT compared with the control group. The results suggest that CEY extender can be improved
with the addition of SOD and BHT.