how often do turkeys need to eat?

I figured out how to fill the bar for the turkeys, and the website says that they die if it goes empty. But it doesn't say what this means time wise. I filled it with seaweed mushrooms and worms and woodchippings and stuff.
so does 75 percent full mean 7.5 hours or 75 hours or what? how often do i need to check on them.
so does 75 percent full mean 7.5 hours or 75 hours or what? how often do i need to check on them.