Effect of linoleic acid-albumin in the IVM and IVF media on survival of frozen-thawed pronuclear bovine zygotes

Bovine oocytes were matured and fertilized in a medium supplemented with or without 0.1% linoleic acid-albumin (LAA). The presumptive pronuclear-stage zygotes were frozen-thawed in the medium containing 1.5 M ethylene glycol with or without 0.1 M sucrose. The post-thaw survival of the zygotes was assessed by blastocyst development in vitro. In non-frozen control groups, 66 vs 64% (p=0.757) of the zygotes that were produced in the presence vs absence of LAA cleaved and 25 vs 27% (p=0.883) developed to blastocysts, respectively. After freezing and thawing, similar proportions (53-65%) of the zygotes appeared to be normal regardless of the LAA treatment in the IVM / IVF media (P≥0.775) and sucrose inclusion in the cryoprotective medium (P≥0.177). However, the post-thaw cleavage rate of LAA-treated zygotes (45-54%) was significantly higher (p