ffect of addition trehalose and steps of freezing on sperm properties of bull frozen in liquid nitrogen.

Object of study to improve semen preserve ability through the use of trehalose sugar as extender additive expressed in frozen semen and education effect steps of freezing on sperm properties. The research trail was carried on the semen samples collected from 4 bulls through a period of 16 weeks, were diluted with Tris-based extender containing different Trehalose concentrations (viz. 50, 100, 150,200) mM and control, evaluated for semen characteristics at steps of freezing (after dilution, after cooling and Post-Thawing). Results clearly indicated that, 100mM Trehalose group had significantly (P<0.05) higher individual motility in comparison to the 50Mm, 150mM, 200Mm and control group. Moreover, the sperm dead and abnormality was significantly (P<0.05) lower, when compared to the control group. The freezing process negatively affects (P < 0.05) the sperm parameters (individual motility, dead and abnormality), but the current study revealed that this effects were changes from treatment to another’s, it means there is interaction between effect steps of freezing and addition trehalose to Tris diluents of bull spermatozoa, however, overall, this effect was lower when the 100mM trehalose was added to this diluents. Conclussion: The addition of 100 Mm trehalose to TFEG diluents had their benefits on freezing-thawing bull semen. A step of freezing process was detrimental to bull sperm properties, but this effect was less when adding 100Mm trehalose to the diluted.