Commercial extenders and freezing curves for the preservation of sperm cells of white-tailed deer (Odocoileus virginianus)

During the reproductive season of the white-tailed deer, 36 diluted semen samples from deer were evaluated before freezing, and at the time of thawing. The samples were obtained by electro ejaculation from three sedated deer with a mixture of Zoletil (R) and xylazine hydrochloride. Samples were diluted with three commercial extenders Biladyl (R), Trilady (R) and Bioxcell (R) and frozen by applying two freezing curves, the one used for sheep and goat, and the recommended for deer semen. The response variable was the Semen Quality Index for Deer (SQID%) obtained from the estimation of the percentage of gross motility, progressive motility, alive sperms, normal sperms and sperm concentration. The results of the statistical analysis showed differences (p = 0.0301) between the extenders before freezing, resulting Bioxcell (R) with greater SQID (60.77%), while for Triladyl (R) and Biladil (R) rates were 48.39% and 33.01%, respectively. As for the evaluated freezing curves, no differences were found (p = 0.5502) between the recommended curve for deer semen and the curve used for sheep and goat semen. In the present study, the use of the SQID as response variable turned out to be useful in the assessment of diluents and freezing curves.