Artificial oocyte activation is necessary during somatic cell nuclear transfer (SCNT) and can improve development of intracytoplasmic sperm injection embryos. Recent studies indicate that zinc chelators effectively activate porcine embryos by possibly decreasing the mitotic inhibitors and maturation promoting factor activity. The study objective was to optimize the use of Zn²⁺ chelators to activate bovine oocytes; TPEN [N,N,N,″N′-tetrakis(2-pyridylmethyl)-1,2-ethanediamine], TPA [tris(2-pyridylmethyl)amine] and PHEN (1, 10-phenanthroline) were tested. All experiments were completed in 7 replicates including: PHEN 20, 400 or 650 µM; TPA 5, 50 or 100 µM; or TPEN 5 or 100 µM; in vitro fertilized (IVF) as a positive control; ionomycin (ion) followed by DMAP (6-dimethylaminopurine) as a positive control; and dimethyl sulfoxide as negative control. Changes in Zn²⁺ intracellular levels post-treatment and blastocyst formation at d 9 post-activation were evaluated. Generalized linear mixed models on SAS were used to identify statistical differences (treatment was fixed). When treated with any of the chelators, the level of intracellular Zn²⁺ in oocytes was significantly reduced (P < 0.001). All chelators were able to induce artificial activation as indicated by cellular divisions; however, frequency of blastocyst formation was lower compared with the positive controls. Blastocyst production rate was < 10% overall on activated oocytes whereas 22% of the embryos were blastocysts in both positive control groups. When oocytes were exposed to trio-conditions (i.e. ion followed by a chelator+DMAP mix), blastocyst rate (>25%) was comparable to the positive controls. Interestingly, total cell number in blastocysts showed that embryos treated with TPA100µM were closer to IVF embryos than ion + DMAP (88 ± 11 vs 93 ± 15 vs 72 ± 14, respectively; P < 0.06). This study demonstrates that Zn²⁺ chelators can effectively reduce the level of intracellular Zn²⁺ in bovine oocytes and be used to enhance development of parthenogenetic embryos. Further studies will focus on evaluating embryo quality to assess the potential use of Zn²⁺ chelators to improve SCNT derived bovine embryos.