How Do I Determine the Percent Protein in My Horse’s Total Diet? It Is so Confusing.

Customer Q&A

Question:

How do I determine the percent protein in my horse’s total diet? It is so confusing.

Answer:

You are not the only one who is confused by this! Let’s see if we can make it easier for you to understand how to determine the percentage of protein in your horse’s total diet. You have to do some math, but it isn’t too hard.

I will use my horse’s diet as an example.

My gelding is fed 20 lb of grass/alfalfa hay. When I had the hay tested, the crude protein came back at 12%.

He eats 4 lbs a day of a commercial feed that contains 10% protein.

Here is how you work the numbers:

First I determine how much total feed my guy is eating. That is pretty easy: 20 lbs of hay + 4 lbs of grain = 24 lbs in the total diet.

Then I determine how many pounds of protein each part of the diet is contributing. I do this by multiplying the total pounds of the particular feed by its percent protein.

The hay portion of the diet consists of 20 lbs of hay that is 12% protein.

20 lbs of hay at 12% protein equals 2.4 lbs of protein per day.

How did I get that number? When doing the math you have two options:

1) You can use this formula: 20 pounds times 12 divided by 100

2) Or you can move the decimal of the percent over to the left two places and simplify the formula to 20 pounds times .12.

Use whichever formula is easier for you to keep straight.

The concentrate portion of the diet contributes 4 lbs at 10% protein.

4 lbs of grain at 10% protein equals .4 lbs of protein.

(The math: 4 lbs x 10 ÷ 100 = 0.4 or 4 lbs x .10 = 0.4)

Add the two numbers together to get the total amount of protein your horse is consuming per day: 2.4 lbs (from hay) + .4 lbs (from grain) = 2.8 total lbs per day.

Next I figure out what percentage of the total diet is protein. To do that I divide the total pounds of protein provided by the total pounds in the diet.

2.8 lbs of protein divided by 24 lbs of total diet = .1166

To convert .1166 into a percent I have to multiply by 100 and I get 11.66%

My horse’s diet provides him 11.66% protein.

If I decide to add a supplement or any other ingredient to the diet, I can use the same calculations to figure out how much protein it is adding to the diet, if any.

For example, suppose I decide to add a vitamin and mineral supplement that is 24% protein. Sounds like a lot of protein, right? Let’s see how it affects the total protein in the diet.

The directions recommend I feed 4 oz per day. That is equivalent to .25 lbs (16 oz in a pound).

.25 lbs of supplement times 24% protein divided by 100 = .058 lbs of protein per day provided by the supplement.

Remember to update your totals:

New amount of feed in the total diet is 24.25 lbs. New amount of protein in the diet is 2.858 lbs.

2.858 lbs protein ÷ 24.25 lbs of total feed = 11.78

Now the percent of total protein in the diet is 11.78%.