In contrast to the result of this study, Chowdhury
et al. (2004) and Tona et al. (2007) found high hatchability
in fall and winter and lower hatchability in the
summer using data from broiler flocks in Belgium and
data from a duck-breeding farm in Bangladesh, respectively.
However, the effect of season was not related
to the flock age in both studies as it is in this study.
The statistical method used to calculate seasonality in
this study allows for the seasonal fluctuation that occurs.
To justify the result of this study, seasonality was
analyzed in relation to daylight and market price, but
no association was found. Future research is recommended
to find an adequate explanation.