Incubation of thawed canine sperm increases DNA fragmentation.

MAYTE URBANO; JESUS DORADO; ISABEL ORTIZ; MARIA JOSE GALVES; LUCRECIA ALCARAZ; LUISA RAMIREZ; DANIEL ACHA VALLS; SEBASTIÁN DEMYDA PEYRÁS; MANUEL HIDALGO

Bolonia

Congreso; 17th annual European Society for Domestic Animals Reproduction Conference; 2013

European Society of Domestic Animal Reproduction

Currently, sperm DNA fragmentation (sDF) is an important cause in the rapid decline of sperm quality after thawing. The aim of this work was to assess the effect of incubation on canine frozen-thawed semen using the SCDt simulating the conditions experienced by spermatozoa into the female reproductive tract. Semen was collected by digital manipulation. The sperm rich fraction of 12 ejaculates from three different dogs was pooled each time. All the pooled semen samples (n = 4) presented physiological values concerning to routine semen parameters. Then, semen samples were diluted to a final concentration of 100 9 106 sperm/ml in two steps with CaniPROTMFreeze. Sperm were frozen in liquid nitrogen vapours for 10 min and stored into a nitrogen tank. Straws were thawed in a water bath (30 s/37°C) and incubated for 24 h at 38°C before analysis. The sperm DNA fragmentation was assessed in frozen-thawed semen immediately assayed after thawing or after 24 h incubation at 38°C using the Sperm-Halomax (Halotech DNA SL, Madrid, Spain). A total of 500 sperm per slide were counted using fluorescence microscopy. The results were compared by ANOVA and expressed as mean  standard error of the percentages of DF positive cells. The results indicate a significant increase (p < 0.05) in DNA fragmentation when semen was stored after thawing compared to immediately controlled straws (2.73  0.2 vs. 1.46  0.1).