Heat stress on oocyte or zygote compromises embryo development, impairs interferon tau production and increases reactive oxygen species and oxidative stress in bovine embryos produced in vitro.

Interferon tau (IFNT) is the cytokine responsible for the maternal recognition of pregnancy in ruminants and plays a role modulating embryo-maternal communication in the oviduct inducing a local response from immune cells. We aimed to investigate IFNT production, reactive oxygen species, and oxidative stress under the influence of heat stress (HS) during different stages of bovine in vitro embryo production. HS was established when the temperature was gradually raised from 38.