it is a heat-producing light bulb used to keep young chicks warm during the brooding period.
What it does
Newly hatched chicks cannot regulate their body temperature well, so a brooding bulb provides the heat they need .
Week 1- 32–35°C
Week 2 - 29–32°C
Week 3 - 27–29°C
Week 4 - 24–27°C
Week 5+ - Gradually reduce/remove supplemental heat