You may want to shoot a few birds out of the sky, they occasionally drop an egg when they`re shot. If you manage to shoot the egg out of the sky, you can sell the eggs at the market as well. Don`t worry if you`re a bad shot, you could hit an oil field and earn some additional Ka-Ching.
YIKES - your corn stock is disappearing and without it you can`t make next months rent. The reason the stock is disappearing is pigs and turkeys are eating it. Here`s a simple solution - KILL THEM. Blow their little heads off with your rifle and sell their remains at the market to earn money.