Cattle’s Diet (Did You Know Cattle Ruminate?)

Valentine, Nebraska

November 14, 2022

Cattle, sheep, and goats are known as ruminants. They have a four-chamber stomach so they can digest grass and hay. The four chambers are called the rumen, reticulum, omasum and abomasum.

cow-stomach-ruminant

The largest chamber, or pouch, in the stomach is called the rumen. The name “ruminant” comes from this chamber. The purpose of the rumen is to hold and ferment food. In a mature cow, the rumen is very large – about the size of a 55-gallon trashcan. The rumen has been compared to a large food processor because it has millions of tiny organisms that live there naturally and help the cow get the nutrients it needs from the grass.

When a cow takes its first bite of grass, they don’t chew it much before swallowing, and it goes into the rumen. Once they fill up on grass, they find a place to lie down and chew the grass more thoroughly.

Then, they voluntarily “un-swallow” or burp up a mixture of what they’ve already eaten, re-chew, and re-swallow. They do this over and over again. This process is technically called rumination, but it’s more common to hear it as “chewing the cud." A “cud” is food that the cow brings back up to chew again. Cows can spend as many as eight hours a day chewing their cud.

A cow will consume about 2.5-3% of their body weight a day. If the cow weights, 1,000 pounds, that means they’re eating 25-30 pounds of grass and legumes a day. If a person ate like a cow, they would have to eat about 360 cheeseburgers and drink 600 cartons of milk every day.

A good pasture in Missouri with lots of high-quality grass may support one cow per two acres during a good growing year.

A pasture with sparser grass (like you find in northwestern states like Montana and Wyoming) may only support one cow on 50 acres or more.

Factoid 1 - The difference between cows and cattle is that the word "cattle" is plural without regard to sex, whereas the word “cows” refers only and strictly to mature female bovines.

Factoid 2- Pasture vs feedlot. All cattle start out in pasture until they are weaned at a bit under a year. Feedlot cattle are fed a diet of corn and other carbs to fatten them. Pasture cattle eat grass and hay; because they are free to move they are leaner than cattle from "centralized animal feeding operations (CAFOs).