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Scientists Want to Feed Your Moldy Muffins to Livestock

After a little overzealous grocery shopping and a lively week of eating out night after night, we often find ourselves with a pile of formerly delicious food rotting away in the fridge. But instead of throwing it out, we could be feeding it to cows.
Photo via Flickr user Nana B Ageyei

We're all guilty of it. A little overzealous grocery shopping, a lively week of eating out every night, and the next thing we know, we open our fridges to an ungodly stench and the morbid sight of wilted kale and fuzzy yogurt. Begrudgingly and with much self-loathing, we throw item after item of once-fresh food straight into the garbage can. Oops. Then, being out of food once more, we head down to Kroger and repeat the cycle.


But suppose that all of that guilt was unnecessary, and that your stale bagels and bruised apples and mushy cucumbers could go towards a good cause, feeding hungry mouths—even if they're bovine. And, even further on the plus side, it could reduce the agriculture industry's carbon footprint.

New research from the University of Georgia, Athens, published in this month's issue of Journal of Animal Science suggests that standard grocery waste can be efficiently turned into a viable, nutritionally sufficient feed for cattle. Researchers analyzed 115 samples of discarded produce and bakery items procured from major chain stores in the Southern US to test for their nutritional value and cost-effectiveness in the recycling process.

As it happened, it seems pretty possible to turn all of those sad, uneaten goodies into some kind of cow-fattening gruel. One issue, however, is that the food-trash-mulch tends to be "highly variable in moisture and nutrition content," which "does not conform well to having set nutritional standards for feeding," according to the scientists. Which makes sense, since a leftover cheesecake and a cluster of cabbage heads is not exactly an apples-to-apples comparison, calorically or in nutrient content. But no worries; researchers still feel that each load of food waste could be individually inspected and managed accordingly.

From there, the fruits, veggies, and bakery goods were treated to prevent fermentation and rot, and fed to a bunch of cows who found it perfectly satisfactory. Ta-da! A cost effective feed that kills two birds (or feeds two cows) with one stone.

Grain-based cattle feed is currently a major producer of carbon emissions worldwide. According to The Research Program on Climate Change, Agriculture, and Food Security, roughly one-third of livestock emissions originate from land use, with the clearing of forests to grow feed crops as a significant contributor. Because of the massive amount of land needed to grow sufficient food for cows, their carbon footprint dwarfs that of pigs or chickens—by 28 fold.

By offsetting just a little bit of that with hairy cakes and moldering fruit salad, our agriculture system could become ever so slightly more sustainable. But if we could find a way to turn moldy-muffin cow farts into something that doesn't destroy the planet, that'd really be something.