More recently, effects of heat stress on embryonic development in culture was evaluated
in Nelore (B. t. indicus) and crossbred (indicus versus taurus) oocytes fertilized with
Nelore or Angus (B. t. taurus) spermatozoa [23]. The decrease in blastocyst development
rates caused by exposure to 41 8C during 12 h was more evident when the heat shock was
applied at earlier stages of development, particularly for embryos that had a predominant
taurus genotype