Cleavage, morula, blastocyst, and hatched blastocyst yields were evaluated in the control (39 °C) and
HS (12 h, 96 hpi, 41 °C) groups for both time
intervals (Table 1).
Within each breed, rates of cleavage and morula
formation were greater (P 0.05) for oocytes aspirated
after 4.0 vs. 6.5 h (Table 1). The cleavage rate of N
N embryos was higher than H H and H Gir
embryos for both the 4.0 and 6.5 h groups (P 0.05).
The morula yield for H Gir embryos was lower than
for N N embryos in both time intervals (P 0.05).
However, between N N and H H embryos, the
morula yield was different only for the 6.5 h group
(P 0.05). There were no significant differences in
cleavage and morula yields between H H and H
Gir embryos for both groups. The blastocyst yield in
the 4 h group was higher than in the 6.5 h group in all
breeds (P 0.05).