[The effect of partial dissection of the zona pellucida on the fertilization of bovine oocytes in vitro and on the subsequent development of the embryos outside the body].

Influence of partial zona dissection (PZD) on fertilization and cleavage of cow oocytes and on pre-implantation development of embryos obtained by this method was investigated. Decreased concentration of spermatozoa in less degree influenced on rates of fertilization and cleavage of oocytes with partial zona dissection than on intact eggs. The embryos obtained by method PZD can develop in vitro to blastocyst stage. However, their development is slowed down and presence of dissection in zona pellucida can result in premature hatching such blastocysts.