Paula Lopes et al. [21] reported that embryos ( 9
cells) of a heat-resistant breed (Brahman) had better
development up to the blastocyst stage than embryos of
heat-sensitive breeds (Holstein and Angus) after exposure
to HS (41 °C for 6 h). Similarly, Nelore embryos
were more resistant to HS than crossbred (taurine
oocyte zebu semen) [22] and taurine (Holstein) [23]
embryos developed in vitro. Furthermore, Brahman and
Romosinuano (Bos indicus) embryos were more resistant
to HS than Angus (Bos taurus) embryos [24].