GROWING LIVESTOCK: FEED AND WATER NEEDS Feed conversion rates show how much usable product is produced from the food an animal is fed. We never see 100% conversion because the animal has already used most of the energy it has consumed in its life in day-to-day activities; however, some species are better at converting feed to usable product than others are. It may also be surprising how much water is needed to produce meat and dairy product; much of it goes to grow the feed.