# Pearson's Square method of figuring percentages in feed



## MaryOfExeter (Sep 30, 2007)

Before this year, I had never even heard of these, much less knew how to use them. I know a lot of people who don't know how to use them either, so in case you're one of those people, I'm posting this to help.

With a Pearson's Square, you can figure out how many parts, pounds, or percent of each feed you need to mix together, in order to get the desired amount of a nutrient. I've only seen them used for protein, but you can also use them if it's something else you're focusing on, like carbs.

The only downfall to this is you can only use two ingredients at once, to figure for one nutrient percentage. So the more simple, the better.


Alright here's an example:
*Say you already have a premixed feed you bought, but you want more protien in your mix. You decide to use Safflower to up the percent of protien.
Your bag of original mix states it is 11% protien. The bag of Safflower says that it is 16% protien. It's breeding season, and those babies need to grow, so you want your final mix that you feed to your birds, to have a total of 20% protien. ALSO you decided you want to make 50 pounds of your custom mix.*

So you set up a Pearson's Square! It looks like this:









Now, let me explain what's going on here 
*Fiding parts*:
As you can see, your protien percent of your first ingredient, is in the top left corner, and the second, is in the bottom left. The desired percent of protein is in the center.
Now before you do any math, move the name of the first ingredient across to the top right corner. Do the same for the second ingredient._ Remember that the names always move across the square *horizontally*_.
Now for the math. _Keep in mind that your numbers in the square, move *diagonally*._
To get the parts of safflower you need, you take the difference between the percent of your original mix protein, and your desired protein. Soooo....20-11=9 parts. You do the same to find the parts of the orig. mix, 20-16=4 parts of orig. mix.
In total, you have 13 parts of food. If all you wanted to know was parts you needed of each to get 20% protein, then you are set! Those parts can be measured in scoops, cups, or whatever.

*Finding lbs:*
Remember we said we wanted to make exactly 50 pounds? It'd be a lot of trouble weighing parts and measuring them all out! So, we continue the square from where we left off. 
First, we just convert those parts to a percentage. It's easier to keep it in decimal form instead of percents. So, 4 divided by 13 = .31 of orig. mix. And 9 divided by 13 = .69 of safflower.
Now all you have to do, is multiply those decimals by the number of pounds you wish to make. In this case it is 50. What you end up with, is the total amount of pounds of each thing you need to mix, in order to get 50 lbs of 20% protein.


*And trust me, this is easier done than said! *


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## MaryOfExeter (Sep 30, 2007)

I bet you're all confused  I would be, LOL


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## Lovebirds (Sep 6, 2002)

Amazingly, I understand what you're doing. DO YOU BELIEVE THAT??? LOL
I guess I'm just lazy. I scoop up some feed, and sprinkle or pour in some safflower seeds till it "looks" right, then feed the birds.....
It would make life much simpler if I could just go buy the mix with the right amount of protein in it.


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## MaryOfExeter (Sep 30, 2007)

Haha 
I do the same thing. If it feels right. But hey, if I wanted to get technical, I'd know how


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## LostPinesLoft (May 29, 2008)

*flawed example*

pearsons is "animal husbandry 101" and I applaud your efforts.
however you must have at least one component with a higher protein value than your target is.

I hope this constructive, I dont mean to be nitpicky.

Have a good day.
VL


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## MaryOfExeter (Sep 30, 2007)

Thanks. I don't understand why you must though


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## RodSD (Oct 24, 2008)

I've been using that technique to get my feeds right. Yes, LostPinesLoft maybe is correct. The reason is simple. You can't make 11% and 16% to make 20%. In other words, you can't make a diluted one say 11% and 16% to get a concentrated one, say, 20%. You can only go down as in to dilute that 20%. In your example, you can never get a concentration that is greater than 16% safflower.


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## MaryOfExeter (Sep 30, 2007)

OHHHH. Duh, I knew that  Well darn...I'm too lazy to go and change my whole first post, so I'm sure people will read this and know you have to have one higher than your desired percent.


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