A simple way to calculate protein in feed mixes

I have a friend who is smart. This a very handy thing to have. I wish now for a friend that is lucky, and I shall hang out with him more...

I have been slowly getting back into making feed. Making feed is a pain in the butt. It is dirty and cold and barley dust itches. However, there always seems to be extra grain that someone needs to get rid of.  Or bottom bales of otherwise nice alfalfa that can't  be sold as they have dirt stuck to them 

Using a hammer mill to grind old hay or grain seems to rejuvenate it. When I have sent samples in for testing the feed value is good and the animals like the feed.

Mixing a lot of different ingredients can be a little frustrating if you don't have a scale and batch programing on your mixer/grinder. I have a scale I made from cheap Chinese parts and I use a large bin to combine ingredients, but it is rather awkward. as I then lift the bin over the top of the mixer/grinder and dump it in.

Each ingredient has a different percent protein and a different cost. This requires constant calculations to insure a target feed value. It is not terribly difficult as I know that mixing a third peas with 2/3 other grains will get me close. But keeping a running total of cost lets you change rates to save money but still hit your target protein content.

Last year I ran into problems with unexpected price increases on certain ingredients. I had to raise my prices, but when you are only making ten cents per pound, a two cent price change can make a big difference.

The obvious choice would be an Excel spreadsheet.  have been trying to remember how to do spreadsheets. I get mixed up, but I have a friend...

I now have a spreadsheet which allows me to enter the type of ingredient, the amount of the ingredient, percent protein, and the price per pound and it will calculate total protein, total cost per pound, and total pounds of the mix. This then allows me to add the last ingredient to balance the mix. It really works well. I wish it were an app.

I can use this  spreadsheet on my phone (if I use magnifiers.) It needs a little tweaking as some things don''t transfer from Excel to the Numbers app on my I phone.  It would also be nice to have another entry so that I could add the charge for mixing and grinding. 

The way I get around being a licensed feed mill is that I charge for materials and for grinding. I am not selling feed. This way I can change the mix to suit the customer as well as tweak it for what is available. Selling a "feed" would require a label and a guaranteed feed analysis. Which sort of defeats the point of my niche processing idea.