Many cows eat healthier diets than most humans. That's because dairy nutritionists (a cow dietician) precisely formulate rations (recipes) that best fit a cow's age, breed, stage of lactation (milk cycle) and pregnancy status, with consideration for current weather conditions.
Typical cow diets contain hay/grass, corn, soybeans, fat, vitamins and minerals. Hay can be fed as "dry" (chopped fresh or stored in a bale) or as haylage (which is stored in piles or silos) and fermented. Corn can be fed as kernels (usually crushed so kernels are easier to digest and cows get more nutritional benefit) or corn silage. Stored and fermented like haylage, corn silage includes the entire corn plant (see our Corn Silage story). With the aid of computer software, nutritionists work hard at getting just the right balance of protein, fat, roughage (fiber), vitamins and minerals in a cow's diet.
Cows eat foods that we can't
Because cows are ruminants, they can convert forages (grasses) to energy—and convert that energy to milk and meat. Humans can't convert forages to energy. "That makes cows incredibly valuable to us, since they can eat food produced in vast areas where we can't grow people food, such as fruits and vegetables," says Laura Daniels, a dairy producer and dairy nutritionist with Star Blends LLC.
"That makes cows incredibly valuable to us, since they can eat food produced in vast areas where we can't grow people food, such as fruits and vegetables."
~ Laura Daniels
In addition to utilizing forages, cows eat a lot of "leftovers," including food and feed byproducts that people don't consume or use. Some examples include soybean meal (leftovers from making soybean cooking oil), cottonseed (leftovers from making cotton clothing), and brewers grains (leftovers from the beer-making process). Plus, don't be surprised if you see cows chewing on some imperfect pizza crusts or stale donuts. They're willing to eat what we won't. But, it has to be part of a nutritious diet. To be healthy, content and produce quality milk, cows need nutritious, safe and adequate feed.
Total mixed rations are carefully created to meet the nutrition requirements of dairy cows.
On many modern farms, dairy farmers follow a recipe formulated by their dairy nutritionist and combine all ingredients into a "cow casserole," known as a total mixed ration (TMR). However, farmers don't simply throw it all together. Usually, there is a recommended order in which to add the ingredients to the TMR mixer wagon (think of a giant mixing bowl and mixer). Also, forages/grasses need to be a certain length. If the haylage or corn silage chop length is too long, cows will not eat the long stems and, ultimately, they won't get enough fiber—leading to rumen acidosis (upset stomach). If the chop length is too short, feed doesn't spend enough time in the cow's rumen (one part of her four-compartment stomach), which reduces digestibility and, again, can lead to rumen acidosis. The rumen serves as a cow's "fermentation vat."
And, speaking of a cow's stomach, how much typically goes into a milking cow's stomach on a daily basis? About 100 pounds of feed and 30 to 50 gallons of water (about the size of a bathtub). Of all the expenses incurred on a dairy farm, about half goes toward feeding the animals. Thus, it's important for dairy farmers to cost-effectively feed their cattle nutritious diets that support health and optimal milk production.