Question

Why do chicken shout when sun rises.

Answer 1

Roosters crow because 
a) they are marking out territory
They are letting other roosters know where they are, so they don't invade each other's territory
b) they are keeping their flock together
The rooster's job is to make sure hens don't wander away. Crowing allows the hens to know if they have wandered too far

The reason they crow in the morning the most is because of the same reason you hear birdsong in the morning. Birds are more active in the early morning.