Effects of Thymus vulgaris L. essential oil and compounds on development and quality of bovine preimplantation embryos in vitro

Thyme oil is already being used in humans and animals for its various activities; however, little is known about its influence on preimplantation embryos. We aimed to investigate the effects of thyme oil on the growth, development and quality of embryos produced in vitro. A total of 266 blastocysts were harvested from 936 oocytes in 11 replicates. The addition of thyme oil significantly increased cleavage rate (P<0.05) morulae (P<0.01) and blastocyst (P<0.001) yield. Embryo quality parameters were found to be enhanced by antioxidant supplementation at atmospheric oxygen level (P<0.001). High oxygen tension during in vitro culture of bovine embryos is detrimental probably due to the accumulation of reactive oxygen species. Reduction of oxidative stress during in vitro production of bovine embryos may support subsequent development and improve the quality of blastocysts (P<0.001). Thyme oil can safely be used to decrease these adverse effects of oxidative stress in this regard. Moreover, in vitro culture of bovine embryos can be performed using carbon dioxide incubators instead of expensive ones.