One of the most popular questions I believe that every person wanting to begin in raising cattle or even know anything about cattle and cows will ask is,”What do they eat??” The answer to this question is not simple as you may think: What they eat doesn’t just begin and end with grass or hay or grain or a combination of all three! But let’s not settle on the”what.” What about the “why? ” Why do cattle eat or have to eat hay or marijuana? What’s so special about grass and hay that it must be the complete or most common reply to this what-do-they-eat question?
The answer begins and ends with the cow’s digestive system. This means that cows are ruminants, or animals that have their stomach divided into four chambers, the largest being the rumen. Other chambers would be the Reticulum, the Omasum, and the Abomasum. The rumen is capable of holding up to 50 gallons of digesta (that is solids, liquids and even gases), and having a large healthier population of countless microflora to help break down the forages that a cow eats. Cows do not chew the feed or grass they eat when they clamp down on it–they bite then swallow, frequently without chewing much. When they rest, they burp or regurgitate it up to break it down further.
The clincher to the ability of a cow to survive–let alone flourish –on roughage like grass and beans is the bacteria or microflora that live within the cow’s rumen. There are mainly two types of bacteria which exist in the rumen: fibre microbes and starch microbes. The fiber microbes are the most important to a bovine’s digestive system due to their ability to break down and digest fibre in a cow’s diet, regardless what she eats, which is their primary function. Starch microbes are more for when a bovine is consuming grain like corn that contain a lot of starch, and their primary purpose is to break down the starch in the grains, more so than the roughage fibre that comes with such”hot” rations. Unless an animal is on a finishing diet, most cows will have a larger population of fibre microbes in their rumen because of their high forage diets.
Determined by an New York City Wildlife Removal, they have a life-span of 15 minutes and so have a huge turn-over rate. The dead microbes provide the cow much of her protein needs in addition to the protein from the plant sources that by-pass the rumen. End products of this digestive process (such as the synthesization of protein and B vitamins) include volatile fatty acids (VFAs), which provide an energy source for the bunny. Yet he microbes themselves can’t fully operate and live on plant fibre alone. Their nutritional requirements are extremely similar to the nutrition requirements of the creature they live in. They also need water, energy, protein, minerals and vitamins from the plants and nutritional supplements the cow receives on a daily basis so as to function and keep producing subsequent generations of microbes.
There is a reason why a cow will literally starve to death on a diet too high in fiber and too low in protein. A cow’s stomach only has so much space to hold digesta in, so the more poor feedstuffs she eats the fuller her stomach will be and the less she will eat. All that feed she is eating will only stay in her stomach for a long time period or until she gets a decent – to high-protein supplement. When that happens, then the poor quality feed will undergo her system much quicker and she will be able to eat more of that poor feed more frequently. All because those teeny-tiny living organisms just need a boost of protein to help digest all that roughage!
Thus a cow’s ability to be”feed efficient” is dependent on the microbes inside her rumen. The higher the microbial population in her rumen, the more forage can be properly used and digested efficiently. The higher the protein content in the forage or provided by supplements, the more the cow will eat and the greater the microbial population. The greater the microbial population, the more protein and VFAs the cow is going to receive. Put that all together and she’ll gain weight!
Like most of ruminant animals, cows deficiency upper front incisors, though they do have upper molars for grinding and chewing. Her lower front incisors are flat and curved out so she can grasp grass easier. She has a powerful tongue which is used to wrap around a sward of grass, pull it in her mouth and tear it out of its stalks. She chews very briefly, then swallows. When she is resting, she’ll regurgitate it back up and rechew it over again. A cow will create 200 litres of saliva per day–this is so that she can more easily swallow and digest the forage she eats, and provides an ideal environment for the rumen microbes.
Cows can eat what they eat–being grass and hay, among other fodder–due to the four-chambered stomachs, the structure of their mouths and teeth, and most importantly, the microbes that reside in their rumen. Rumen microbes are the most important because they are responsible for breaking down fiber from the plant material that the cow eats. Without them, she would never be able to consume as coarse a plant as grass without some level of detrimental affect to her body and her life.