Yes. When it is time to move birds down, a 24 hour preheat period is usually standard procedure. Unfortunately, just as ammonia purged in the brood chamber at pre-placement, the ammonia will purge off the off chamber floor once the floor reaches 80-85 degrees. This can occur as late as 36-48 hours post move down. The ammonia purge during this time will have significant impact on the performance of the birds causing a loss of weight and feed conversion. By applying PLT one (1) hour prior to move down, it will drastically reduce ammonia challenge, help birds migrate faster, and minimize vaccination stress thus increasing your bottom line..