This study evaluated the protective effects of supplementation with three different sugars on the motility, morphology and DNA integrity of rat epididymal sperm chilled and stored at 4 degrees C Epididymides were obtained from each donor. Rat epididymal sperm was diluted in Ham's F10 plus raffinose, Ham's F10 plus trehalose, Ham's F10 plus fructose, and Ham's F10 medium for control purposes. Thereafter, the extended sperm were chilled and stored in liquid form at 4 degrees C. Sperm motility, morphological abnormalities and DNA damage were determined at 0 and 12 h after chilling. No significant difference was observed in any of the parameters evaluated at 0 h, before storage (P > 0.05). After 12 h of storage, all sugar additives led to statistically higher motility, normal sperm morphology and DNA integrity in comparison to the control group. Raffinose gave the best motility percentages (32.86 +/- 1.84%) after 12 h of storage at 4 degrees C, compared to the other groups (P < 0.001). In conclusion, Raffinose, trehalose and fructose provided a better protection of sperm functional parameters against chilling injury, in comparison to the control group. Crown Copyright (C) 2012 Published by Elsevier Inc. All rights reserved.