Being the holiday season, people tend to visit family, go to parties, and consume large amounts of food.    Typically, this behavior does not lead to necessarily the healthiest food you eat all year.  Quite the opposite, in fact.  I know I certainly don’t eat very healthy during the holiday season. 

Ok, I know what you’re thinking, “why the hell is the cow kid talking about our holiday vices?” 

She thinks your hair looks tasty. Photo credit Trevor Beaudry

Well, I’ve got a question for you.  What is “eating healthy”?  And how do you know that what is considered “eating healthy” is what your body actually needs? 

Now, I’m sure the few of you that have had some human nutrition classes might be able to give me fairly reasonable answers.  But, the grand majority of you, the rest, would probably give the same answer as me.

What is that answer? You’d mumble something about lean protein and eating your fruits and veggies then give an answer something like…

I dunno.

You want to know the funny bit? The punch line as you’d call it.

I know what “eating healthy” means for a cow despite not knowing for myself.

Over the years, scientists have determined exactly how much of nearly every nutrient a cow needs in order to perform to the best of her genetic capabilities.  We can analyze the ingredients that go into the ration for the cow, perform some calculations, and tell you with reasonable accuracy how much milk the cow should produce.  We know the amount of energy a cow requires and the proportion of that energy that she can obtain from consuming fat before there is a negative impact on productivity.  We know the percentage of a cow’s diet that should be made up of protein to maximize production.  We have even figured out that a portion of the protein a cow is fed needs to pass through the rumen without being broken down so it can be absorbed in the small intestine. 

A lactating cow drinks between 30 and 50 gallons of water every day.  Gallons!  For every gallon of milk she produces about 400 gallons of blood has to pass through her udder.  Let’s say she’s producing 86 pounds of milk per day. Since a gallon of milk weighs 8.6 pounds that means she would be producing  10 gallons of milk per day requiring 4,000 gallons of blood pass through her udder every day. 

What I find most surprising is that we’ve even determined what amino acids are the most limiting to a cow based upon her nutritional requirements and what is supplied by the ingredients that commonly make up her diet.  There are 21 essential amino acids which are the building blocks of proteins (please don’t ask me to list them all).  Of these 21, there are two, which are the most limiting in a cow. 

I think the foods over there. Photo credit Trevor Beaudry

One last question before I wrap up.  What are the most limiting amino acids in humans (using google is cheating)?

I’m guessing your answer is probably similar to mine.

I haven’t got a clue, but the two most limiting amino acids in cows are methionine and lysine.

In monogastrics like us, adding an amino acid supplement would be simple. You simply make the amino acid into a powder and add it to whatever you’re eating so it goes to your stomach and gets absorbed in the small intestine.  Farmers use this method with pigs all the time.  Unfortunately, the ruminant stomach throws a bit of a monkey wrench into this approach.  If you simply sprinkle the limiting amino acids on top of a cow’s food, they get all used up by the microbes in the cow’s rumen and never get absorbed in the small intestine to be used by the cow.  This obstacle calls for some creative measures:  protected methionine products.   

These products consist of a methionine core with an outer covering made up of a material that is not digestible in the rumen.  The trick is the coating is removed by the acid and digestive juices in the abomasum allowing the methionine to then be absorbed in the small intestine after bypassing the rumen microbes.  So, next time you think a farmer doesn’t really care about his cows, remember he knows far more about what he fed them for dinner than what is in that fruitcake Aunt Lucille just dropped off.