The normal distribution of data, reported as mean and
standard deviation, about the estrous cycle and estrous and
diestrous lengths were tested by the Kolmogorov–Smirnov
test. No deviation from normality was detected.
For the hormonal analysis, the day of blood collection
was normalized for ovulation (Day 0): preovulatory days
considered from Day 6 to 1 and postovulatory days from
Day 1 to 18. Length of estrous cycle, estrus, and diestrus
were analyzed using a two-way ANOVA, in which the
season and the cycle within each season were used as
factors. The follicle size at Day 5 and at ovulation was
analyzed using a one-way ANOVA, in which the seasonwas
considered the factor. The plasma concentrations of E2 and
P4 were analyzed using a two-way ANOVA, in which the
season and the day (pre- or postovulation) were considered
as factors. In all cases, the post hoc evaluation was performed
using the Scheffè’s test. The differences were
considered significant with P-value less than 0.05. All data
were analyzed using the software PASW (SPSS) version 18
for Windows platform.