| This study compared the sex-sorting effect of three bulls; evaluated the influence of sex-sorting and cryopreservation on sperm viability and the effect of fertilization and the development capability of embryos. In addition, this study compared the influence of BO method and percoll method on development capability of embryo of sorted-frozen spermatozoa. And the quality of bovine IVF embryos of sex-sorted and unsorted sperm were evaluated by simplified method of chemically-defined differential blastocyst staining.The results showed that there were significant differences (4.1×10~3 vs 4.5×10~3 vs 5.3×10~3,19.3% vs 14.5% vs 11.0%, P<0.05) in the sorting rate and dead sperm rate among three bulls, except the purity of X sperm. There were no significant difference between the unsorted fresh and the sex-sorted fresh semen in sperm viability (84.5% vs 83.4%,P>0.05) in vitro culture for 10min; But there were significant differences (62.5% vs 55.4%,P<0.05) in vitro culture for 6h;The cryopreservation significantly reduced the sperm viability of unsorted spermatozoa (84.5% vs 55.2%) and sex-sorted(83.4% vs 55.3%) spermatozoa. There was significant difference between the sperm viability of sex-sorted frozen and unsorted frozen in vitro culture for 4h (9.1 %vs 25.9%, 22.1%vs 35.1%, 21.5%vs 36.5%, P<0.05) . So, We concluded that the damage due to sex-sorting treatment on bovine spermatozoa is minor related to that caused by cryopreservation. However, the fertile life span of spermatozoa was considerably reduced by sex-sorting. And the tolerance of sex-sorted spermatozoa to cryopreservation was worse than that of unsorted spermatozoa.This study compared BO method and the percoll method, and the results showed that the cleavage and blastocyst rates of percoll method was higher than BO method, but there was no significant difference (50.3% vs 45.3%; 23.0% vs 19.1% , P>0.05).We also compared the effect of IVF with sex-sorting and cryopreservation sperm of three bulls. The results showed that there were significant differences in the cleavage rate with different sperm types(fresh, unsorted-frozen, sorted-fresh and sorted-frozen) (73.6% vs 63.9% vs 64.2% vs 45.7%, P<0.05) .But there were no significant differences in blastocyst rates (P>0.05) . The blastocyst rates of bull 1 were lower than bull 2 and bull 3 (24.3% vs 29.7% vs 29.6%, P<0.05) . The numbers of inner cell mass in-vitro produced bovine blastocysts with sex-sorted and unsorted sperm were 29.5 and 35.8 respectively, and the percentages were 27.8 % and 32.8 %. There were no significant differences (P>0.05).So, we conclude that the sex-sorting has no effect on the development of embryos, but there are significant differences between bulls. Thus, it is feasible to apply the sorted spermatozoa to produce sex-sorted embryos. And the selection of suitable bulls used for the sperm sorting would be great valueable to improve the sex-sorting efficiency and the quality of sex-sorted spermatozoa which is applied to in vitro fertilization.
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