Salvaging urospermic ejaculates from brown bear (Ursus arctos)

Effect of colloid (Androcoll-Bear, Percoll, and PureSperm) selection on the freezability of brown bear (Ursus arctos) sperm

“…Thus, in accordance with previous reports showing that selected spermatozoa exhibit better motility and VIAB parameters in samples submitted to different potentially detrimental situations (urine contamination [17], blood contamination, and double freeze-thaw cycles [48]), we obtained an increased ability of sperm to survive freezing than in control samples. This observation could be because of the sperm being more liable to cryoinduced damage in the presence of blood or urine; if these contaminants are removed, the sperm are better able to survive cryopreservation.…”

“…In this regard, taking into account the biological value of brown bear samples, selection through a colloid could lead to an improvement in the quality of the samples stored in a Genome Resource Bank. Previous studies have indicated that the use of colloid centrifugation resulted in an increasing of after thawing motility and VIAB of urospermic ejaculates treated with PureSperm [17]. A similar result was observed for hemospermic bull samples processed through Androcoll-B [50].…”

“…Thus, for the ejaculates of some species, centrifugation of semen before cryopreservation is necessary to reach an appropriate cellular concentration (dog [12], stallion [13,14], and brown bear [2,6]) or even to remove seminal plasma (goat [15]) and clean urinecontaminated samples (horse [16] and brown bear [17]). Despite previous studies assessing the deleterious effects of centrifugation, this procedure does not appear to be harmful for brown bear spermatozoa [18,19].…”

“…This two-layer gradient has been used previously with effective results in the selection of brown bear sperm samples [17,28].…”