Fig. 4.

Effect of REAC treatment on DNA integrity, as evaluated by the neutral comet assay, of stallion spermatozoa during 72 h. of storage at 4 °C. Evaluated parameters included the comet area (pixels) and the percentage of DNA in the head. For each parameter, panels a and b show the mean ± S.E values determined at the different time points in each experimental group. A total of 16 ejaculates collected from eight stallions of different breeds (1: Thoroughbred; 2, 3, 4, 6: Arabian; 5, 7, 8: Warmblood) were used. Images show representative comets following application of the neutral comet assay: (1) non-fragmented sperm nucleus; (2–3) fragmented sperm nuclei. Asterisks indicate statistical differences between REAC treated and untreated controls (General Linear Model): p > 0.01. Different letters indicate a statistical difference among values recorded at the different time points within the same experimental group (General Linear Model): p > 0.01. Upper case letters: REAC group; lower case letters: control group