A question that we get from children and even some adults when they visit our farm is “Can the cows bite me?”. We always smile and assure them that no the cows won’t bite them and then inform them why a cow can’t bite them.
Cows are herbavores which is just a fancy way of saying they eat plants. Before I get too far into this lesson on dairy cattle nutrition I must answer the question of why cows can’t bite. Cows mouths are designed for eating grasses 4″ and up from the ground. As you can see in the picture cows only have teeth on their bottom jaw in the front and what is called a dental pad on the top. An animal with only one row of teeth isn’t going to waste it’s time trying to bite people.Although the cow in the picture which is NOT mine makes me wonder. I couldn’t get any of our cows to show me their teeth so Google pics is as good as we’re getting.
When eating they use their tongue to pull the grass into their mouth then bite down on it pinching the feed between their teeth and dental pad. Next they move their head forward cutting the grass with their bottom teeth. The cow then chews the mouthful of food into a partially chewed wad and swallows it. In the back of their mouth cows have molars on the top and bottom to grind their food up when they are chewing their cud. Chewing cud is when a cow regurgitates one of those food wads and chews it usually around 55 times before swallowing it again. That’s impressive when you figure that they spend 7 to 10 hours chewing cud per day. They do all this regurgitating and chewing to help their stomach digest the hard to break down plant fiber.
Dairy cattle are ruminants meaning they have a four compartment stomach that allows them to digest plant fiber. They
are able to digest plants because of the compartment in their stomach called the rumen. The rumen is about the size of a 55 gallon drum in a mature cow and is populated by bacteria, fungi, and protozoa which break the plant fiber down into acids which the cow can then use as energy. The cow also gains nutrients by digesting the microbes that pass out of the rumen with the digested feed. When we are thinking about what and how to feed the cow we are really considering how to best feed the microbes in the cow’s rumen. This relationship between the cow and microbes in her stomach is a great example of the complex biological systems at work everyday on a dairy farm.
On our farm we feed our cows what is referred to as TMR or a total mixed ration. The ration is formulated using computer software that helps us figure out the right amounts of each ingredient to feed to meet the cows energy, protein, and mineral needs. Sometimes I wish I had a computer program to tell me what to eat to be healthy! The TMR mixer mixes all the ingredients together. We put the mixed feed in bunks and wagons that the cows have access to all day so they can eat at their leisure. This way every cow has the same chance to get the nutrients they need to stay healthy and produce wholesome milk.
We use three main ingredients in our TMR. The most important ingredient is haylage which is chopped up alfalfa, clovers, and grasses that have been fermented in a giant plastic bag. The next ingredient is corn silage which is the whole corn plant chopped up and fermented. The last ingredient is ground barley with salt, minerals and kelp in it. The haylage is high in protein which complements the corn silage that is high in energy. The barley is used for more energy and as a carrier for the salt and mineral. We also offer salt and mineral for the cows to “free-choice” so they can meet their needs if more is required than is in the TMR.