Peanuts, flax, sprouts and avocados: It's not the menu at a health food deli, but the menu inside some barns. What's more, many farmers experimenting with these gourmet feeds are growing the ingredients themselves.

Take Russ Kremer, the Missouri pig farmer whose operation served as the inspiration for the 2011 Chipotle ad featuring Willy Nelson. Kremer hasn't bought commercial animal feed in 30 years. Instead, he grazes his hogs in a pasture, and grows (or buys from neighbors) grains and legumes to supplement their nutrition.

Kremer and some of the other farmers developing specialty feed say they are willing to shoulder the extra cost and time to produce it because they're turned off by conventional feed mixes. The conventional mixes are what most of the hogs in the U.S. consume, and can include commodity corn and soybeans, blood protein, animal waste and rendered fats, according to Kremer.

Kremer also runs a co-op where farmers can pool resources to mill their own feed. "We opt for grains like barley and oats as often as possible, because most corn and soy is now [genetically modified]," he says. Read more on the NPR food blog.

Note: Kremer was also the recipient of this year's NRDC Growing Green award (see video below).