Master of Science (MS)


Biomedical and Veterinary Medical Sciences - Veterinary Clinical Sciences

Document Type



The objectives of this study were to determine what effects iodixanol would have on total and progressive motility, plasma membrane integrity (viability), acrosome integrity and DNA structure when present during cryopreservation of equine spermatozoa,. We hypothesized that the addition of iodixanol would improve post-thaw values for measured parameters. Ejaculates from six stallions were collected, centrifuged at 900 x g for ten minutes to remove supernatant, and suspended to 200 x 106 cells/ml with 0%, 2.5% and 5% iodixanol in an egg-yolk based extender and cryopreserved. Before and after cryopreservation sperm motility was assessed by computer assisted semen analysis, and samples were stained with SYBR-14/propidium iodide (PI) for viability, with PI/fluorescent isothiocynate-PNA (Arachis Hypogaea) for acrosome integrity and assessed by flow cytometry. Sperm DNA was evaluated using the sperm chromatin structure assay test and assessed by flow cytometry. The mean (± S.E.) percentage pre- and post-thaw total motility, progressive motility, viability, acrosome reactivity, COMPát and MEANát were analyzed using Shapiro-Wilk test to evaluate if data followed a normal distribution. When results followed a normal distribution an ANOVA was performed and where a significant interaction of treatment was observed (p=0.05), a Tukey-Kramer post-hoc test was applied. If results did not follow a normal distribution, a binomial logistical regression was performed. The 5% post-thaw treatment group showed increased viability and decreased DNA damage (p<0.001). Although the 0% group showed greater total and progressive motility than the 2.5% group, it was not greater than the 5% group. The 5% post-thaw treatment group had significantly more (p<0.001) non-reacted and damaged acrosomes than both the 0% and 2.5% groups. These findings suggest that the presence of iodixanol during cryopreservation may have a beneficial effect by protecting plasma membrane and sperm DNA, but the exact mechanism of action is unknown.



Document Availability at the Time of Submission

Student has submitted appropriate documentation to restrict access to LSU for 365 days after which the document will be released for worldwide access.

Committee Chair

Lyle, Sara K.