Embryos produced by fertilizing oocytes from Brahman
cows with semen from Angus bulls were more
resistant to HS than embryos produced by Holstein
oocytes fertilized with Angus semen [25]. However,
resistance of embryos to HS was not significantly different
between Holstein oocytes Brahman semen and
Holstein oocytes Angus semen [25]. Therefore, we
inferred that the contribution of the oocyte was more
important than the contribution of the sperm in determining
the resistance to HS.