the gilts entering the gilt pool in the cool season (31.4+- 0.5days)
had a shorter interval from entry to first observed estrus then the gilts entering the gilts pool in hot(37.5+-0.5days)
and rainy seasons (34.3+-0.5days)
Gilts exposed to a low temperature,a high temperature humidity index or a shot photo period during the 30 days before entering the gilts pool were older at first observed estrus then gilts exposed to a low temperature,low THl and/ or long photo periods.