Effect of Cryopreservation on Integrity of Plasmatic and Acrosomal Membrane of Bulls Sperm

Plasmatic and acrosomal membrane integrity has been used as valuable information for determining sperm quality, because is important to know the morphological and functional role as cellular delimitation and in effective cell interactions. The aim of this study was to determine cryopreservation effects on sperm percentage of vitality, number of damaged acrosomes (DAR), the structural and functional sperm plasma membrane integrity in 5 fresh ejaculates and 5 thawed strauws of 5 bulls by using the eosin-nigrosin stain. The functional integrity of these membranes were evaluated by osmotic tests (HOST and ORT). The data was analysed by GLM procedure, and when differences were detected, LSMEANS was used to quantify the effects. Significant differences were found on seminal quiality parameters (VIT, DAR, ORT and HOST) between fresh and thawed sperm. Freezing-thawing procedure had detrimental effect on the integrity structural and functional of MP and MA in the spermatozoa evaluated (P<0.05). However, it was possible to demonstrate that the spermatozoa have different pattern of resistence to the detrimental effects of cryopreservation. Then, this study confirms that cryodamage could happen indistinctly on the structural and functional MP and MA integrity, which would affect the fertilizing capacity of the seminal samples destined for Artificial Insemination.