You can.
It is a flag that is changable via a Mayor+ Application.

 

if you toggle the flag using the forum application you will also be turning on hostile mob spawning.

It will be like the wild except protected. If you have spawning boxes you can create mob farms BUT DO NOT MAKE MOB TRAPS! very very bad....

animals will breed using wheat and spawn in the wild according to game mechanics.

 

You must be in a town that has had the flag changed already by the mayor to be able to have chickens in the town.
If you are the mayor, you can change the flag of your own town.

 

Well u can have chickens in any town. Just can't spawn them using eggs or breed them with wheat. U will have to play pied piper with wheat and lead them home from the wild.