Dairy cows weigh about 1,000lbs depending on their breed, meaning cows can eat a lot—up to 100lbs a day! Like humans, cows have nutritional requirements that dairy farmers must meet to sustain healthy, happy cows. These ladies can’t survive off only grass from grazing. They need a healthy mixture of foods reliant on factors like age, weight, and milking or dry. Luckily, cows are unlike humans in what they can and cannot eat.

Cows don’t really have four stomachs, but they’re very effective. There are four chambers for cows to take advantage of when choosing a diet. There is the rumen, the reticulum, the omasum, and the abomasum. The food spends hours in a cycle of being chewed, digested, and chewed again. The rumen, the largest part of the cow’s stomach, begins the digestion process, breaking down the food and cellulose, which humans can’t break down. Food then moves to the reticulum and the omasum to be further digested. The last chamber, the abomasum, completes the digestion process and releases essential nutrients. With their four-chambered stomachs, cows can break down products humans cannot and use the energy and nutrients in these products that would otherwise go to waste.
To provide cows their nutritional requirements, dairy farmers feed cows a mix of feed they call Total Mixed Ration, or TMR. Most of a dairy cow’s diet is comprised of plants, and not the veggies you may find on your plate. This part of the diet consists largely of corn and its leaves and/or chopped alfalfa and its hay. In addition to plants, cows also enjoy grain. They aren’t snacking on toast. While cows can receive grain grown specifically for their meals like sorghum, cows also consume Distillers grain and Brewers grain. Distillers grain is a byproduct of ethanol production. Brewers grain, meanwhile, is a byproduct of brewing beer from rye, oats, wheat, or barley. These grains can come from other businesses that would consider it waste, like local breweries.
But this isn’t the only byproducts cows will happily eat that humans will not. Leftover soybeans and canola used in producing cooking oil, almond hulls, cotton byproducts like leftover cottonseed, and even citrus pulp from juice are used in TMRs. Food scraps from grocery stores, remains from bakeries and restaurants, and more create potential food for a cow’s TMR. If cows didn’t consume the byproducts that comprise their TMRs, humans would throw much of their own food waste away. Cows help humans live a more sustainable lifestyle than we would without them. The scraps and byproducts of our favorite foods can be brought to a local dairy that will help everyone in the community. Humans are lucky that cows aren’t picky eaters.