More efficient than just deer hunting or raising livestock. Invest in 20 trap cages, give or take, set them out in some woods each trap say 50 meters apart, set with dog food and water. Check on them twice a week. Dispatch trapped animal with a nearly silent air hand pistol, store animal in bag, reset trap. Later put bag of animals in deep freezer. Once a month on a Saturday morning thaw animals, assembly line fashion gut, skin, chop up meat, put in meat grinder, make burger meat and sausages. Raccoons, opossums, rabbit, and squirrel meat, all ground up, properly soaked in water and salt, then marinated, then freeze. Rotate traps to different woods. Potentially a thousand pounds of meat a year, done right. Put skins in a tanning solution to make hides, to make hats, coats, gloves, blankets, and rugs. Same with fish. Get say 10 fish traps, set them out in a nearby lake or stream, check twice a week on hike, which is your daily exercise. Freeze fish, then gut and de-scale before cooking. Potentially another 1000 pounds a year of fish. Prepare now. Before the SHTF.