How do I figure percent protein in feed?

[Betania]

I had somebody give me their feed mix ratios, and it costs a little less than our lamb grower if we do it with corn, and just a little more if we do it with oats. I am trying to compare it to the lamb grower. She said her lambs grow really fast on it, but I just want a little more information. How do I figure out the percent protein of a feed if I have the percent protein of the ingredients? Here is the mix. I added the protein % for the corn and oats, from off another site, but I can't find anything that tells me how to figure the complete percent protein.
400 lb cracked corn- 10%
100 lb oats- 13% (Or you can replace this with corn)
50 lb lamb 34% supplement
40 lb Soybean meal - 46%
20 lb Liquid Molasses

If somebody can explain how to figure the overall percent protein, I'd really appreciate it!
Thanks!

[Bigiron59]

Some one will figure it out, and corn is closer to 7 protein. Has not been 10 since the 70's.

[Bigiron59]

Ran it through the ration balancer I use. This is a finisher type ration . 13.8 protein dry mater or 12.3 as fed. The real danger is the cal / phos balance is inverted. You will give the wethers urinary calculi( water belly) if this ration is fed long term.  Your better off using  300 pounds of the sheep balancer and 1700 lbs of grain for a finisher ration and 500 lbs of the sheep balancer and 1500 lbs of grain for a grower ration. Tens of thousands of lambs are fed this every year and it's balanced for minerals ,protein and cal,phos. It will have vits,decoxx or bovatech in it for coccidia, and a unrinary acifier for water belly.
It's likely the most economical choice out there. And if you have grain. You can buy the 34 balancer and mix your self.

Most other rations are going the have problems.

[EmsoffLambs]

There are various free ration balancing programs that you can find online. Many just use Excel. 15 years ago, my college professor was pretty old school and made us balance rations with pencil and paper. It can certainly be done, but these days there are so many computer programs that will formulate least cost rations, anyone with basic understanding can do it. Google 'sheep ration spreadsheet" and you will come up with an assortment of options.

[EmsoffLambs]

http://www.sheepandgoat.com/#!rationsoftware/c14p1

There are a bunch to choose from right here.

[ColdCreek]

Lol, I guess I'm still old school as I make my students learn how to do it on paper still as well.  It really isn't hard to balance protein once you learn how to use the Pearson square. 

[EmsoffLambs]

That works unless your ration contains more than a couple ingredients. It gets trickier after that.

[Betania]

Ok, thanks everybody!

[Kgb]

To do what you want (calculate the % protein of a specific mix) multiply the % protein by the % of the ingredient (amount in feed).  Do this for each ingredient and then add them together ... Simple.

It is called a "weighted average".

[Betania]

Kgb- Thanks so much. That is so much simpler for me right now. I will probably still look into the link Emsoff gave me, when life slows down a bit. I don't have much time just yet though.