The Effect of Cushioned Centrifugation, with and without Enzymatic Reduction of Viscosity, on the Motility Pattern and Kinematic Parameters of Dromedary Camel Bull Spermatozoa

SIMPLE SUMMARY: Semen processing procedures in the dromedary camel species (Camelus dromedarius) are still underdeveloped as compared to other domestic species. The viscosity of the camelid’s ejaculate presents challenges that must be overcome with specialized procedures. In this study, we have proven that seminal plasma affects the motility of dromedary camel epididymal spermatozoa, and we have evaluated the effect of a cushioned centrifugation procedure (900× g for 20 min) with and without enzymatic reduction of viscosity for processing dromedary camel ejaculates. The obtained results showed that the dilution of dromedary camel ejaculate and centrifugation with cushion fluid improves the motility pattern of dromedary camel spermatozoa. Moreover, the use of the protease enzyme Papain could help in further reducing the viscosity of camelid ejaculates and in obtaining higher sperm recovery rates following cushioned centrifugation. ABSTRACT: In order to contribute to the development of semen processing procedures in camelids, the aims of the present study were to evaluate (i) the effect of 35% seminal plasma incubation on dromedary camel epididymal sperm motility and kinematic parameters, (ii) the effects of centrifugation, with cushion fluid and enzymatic reduction of viscosity (Papain + E64) during ejaculate processing, on the motility and kinematic parameters of dromedary camel ejaculates. The incubation with seminal plasma significantly reduced the percentage of progressively motile spermatozoa as well as the proportion of medium progressive spermatozoa whilst increasing the percentage of non-progressive spermatozoa. The centrifugation procedure improved the sperms’ kinematic parameters, and the highest values were observed for samples centrifugated with cushion fluid. The samples treated with Papain + E64 showed a significant increase in both total and medium progressive spermatozoa, along with a reduction of non-progressive spermatozoa (p < 0.05). The results of this investigation show that a simple, cheap, and effective procedure, such as cushioned centrifugation, could improve the motility patterns of dromedary camel spermatozoa; in combination with enzymatic reduction of viscosity, this method leads to the best results in terms of recovery rates and sperms’ kinematic parameters.