Abstract:

Tree experiments were designed to optimize ram semen cryopreservation and to examine the effect of the extender B osmolarity, extension time with extender A and B, presence of glycerol in freezing media, cooling rate from 30ËšC to 5°C, and dilution rate on post-thaw ram semen characteristics and fertilization.  Ram ejaculates of thick consistency with rapid wave motion (>+++) and >70% initial motility were pooled. Pooled semen was diluted with Tris based extender using a two-step dilution method. Semen motility and morphology related parameters were assessed at the following five steps : (1) Fresh, (2) after dilution with extender A, (3) at 5°C, (4) after equilibration, and (5) after thawing at 37°C for 30 min. The extender osmolarity affected significantly post-thaw semen motility, defected acrosomes (DA) and total morphological defect (TMD), generally.

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