HELP! Big wound on chickens neck

[starrmar006]

I have a 5 month old rooster that has a huge wound on the back of his neck, it is so deep that it is not bleeding. He is separated from everyone else. I don’t know what to do, any ideas
I’ll put pictures in a little bit

 

[starrmar006]

Here are the pictures

 

[starrmar006]

Any ideas???