Abstract
The aim of this study is to elucidate sperm chemotaxis and to set up the optirnal condition for selection of motile and capacitated sperm from hovine frozen-semen. Thus, the effects of semen-washing after thawing, concentrations of progesterone (P4) and bovine serum albumin (BSA), and sperm-washing frequency on sperm selection were examined. For evaluating their effects, number, viability and acrosome reaction of sperm swim-up seperated from semen, which were incubated for 30 minutes at 36$^{\circ}C$ in the M2 solution containing P4 and BSA, were investigated. For frozen-semen just after thawing, sperm recovery and viability were not significantly different between P4-treated and -untreated semen. However, washing frozen-semen decreased the number of sperm and increased the viability of sperm that were recovered from semen treated with P4. Progesterone affected the recovery rate, the viability and the acrosome-reaction rate of sperm recovered from washed frozen-semen. Especially, number of motile and capacitated sperm were highest in semen treated with 50$\mu$g /ml among 0, 20, 50 and 100$\mu$g /ml of P4 concentrations. BSA affected the recovery rate and the viability of sperm recovered from washed frozen-semen that were treated with 50$\mu$g /ml of P4. Especially, the percentage of viable sperm were highest in semen treated with 4mg /ml among 0, 2, 4, and 6mg /ml of BSA concentrations. Repeatedly sperm-washing did not affect the recovery rate and the viability of sperm recovered from washed frozen-semen that were treated with 50$\mu$g /ml of P4 and 4mg /ml of BSA In conclusion, using progesterone and BSA could efficiently make the selection of motile and capacitated sperm from washed frozen-semen.
