Hunger System Balancing (Please Read. This One Is Actually Good!)

Animals should spawn more often on the first 3 days upon joining a new world. Animals would also spawn more often on servers every time a new player joins unless the server turns it off. Make an option called "Do Hunger System On/Off", that would remove hunger when turned on, even in non-peaceful mode worlds. It could be changed with commands as well with the command "/gamerule dohungersystem true/false".