another thing to mention, last summer when we had some intense heat I kept the watermelon in the fridge and very cold to give them a nice cool treat in the afternoon heat, they were happy for it.
My Silkies LOVE watermelon! They aren't so fluffy afterwards though!!! All of my chickens love it and they will eat to the rind and leave it alone. When they are done, I set it out in the yard and the bunnies eat the rest!!!! Nothing goes to waste on my farm!
My Cickens LOOOOOVE watermelon. It's their favorite treat. They eat everything but the rind. I have been feeding watermelon to my chickens for a while now and they are just fine.