Feed protein content?

So, I am working on a plan for growing chicken fodder.  For me this means making a spreadsheet.  Several, actually.  

One of the things I am looking at (for one of my spreadsheets) is the protein content of various types of veggies, greens, grasses, grains, etc.  And I realized that when collecting this data from a variety of sources, they may not be talking about the same thing.  

My store-bought chicken feed says it is 16% protein content.  What exactly does this mean?  

One data source I am looking at specifies protein content as a % of the total calorie content.  Is this the same kind of figure as the 16% on my chicken feed?  

If so, then amaranth greens actually have quite a bit higher protein content (25%) than amaranth seeds (13%), which is not at all what I expected.  
Amaranth seeds
Amaranth leaves

Many thanks in advance.

Reading figures like this can be confusing and can lead to serious mistakes.  I'm reminded of this whenever vegans say that you can get all of your protein from kale and broccoli and such like.  In this case, as well as the case of the amaranth greens, the protein content may be high, but so also is the content of comparatively indigestible fiber, such that it would be difficult or impossible for us, or chickens, to meet all of our protein needs from greens.  Ruminants like cows and goats, because they can break down the fiber for calories, are another matter entirely.  But single stomached critters like ourselves, pigs, and most poultry (geese are an exception) need more concentrated feeds.  I think that most grains and other dry feeds are labeled as to protein (and other nutrients) as a percent per weight.  Moisture and fiber may be included as well.  (so that, if a similar label were created for say, fresh amaranth greens, the water and fiber content would be much higher than for something like corn or soy.)
    As an aside, layers are pretty good at balancing their own rations if you give them a calorie source (grain, cooked roots, etc.) a protein (soy meal, beans, meat scrap, insects) and greens free choice in separate containers.  And the more you can free-range them, the less you will need to feed them anything at all.

From the linked nutritional data...

Amaranth seeds: 26 grams protein / 193 gram serving size = 13% protein.
Amaranth leaves: 3 grams protein / 132 grams serving size = 2% protein.

Some other common contributors to poultry feed contain the following percentages of protein:

Soybean: 37%
Peas: 25%
Wheat: 13%
Sorghum: 11%
Millet: 11%
Corn: 9%

I've noticed that before with amaranth, but never thought it odd?

Both
http://articles.extension.org/pages/67475/feeding-amaranth-to-poultry
and
http://www2.ca.uky.edu/smallflocks/Nutrition-Amaranth.html
Include amaranth leaves as higher in protein than seeds, and both directly relate to chickens, so there's no mistaking it with ruminant percentage.

....Perhaps chicken food is better when it isn't boiled?

Honestly, I'd just choose a number and stick to it. Basically every source has it's opinion, and with many animals, you have a significant range of leeway, such as with chickens (16%-21%). Better to little protein than too much. Too high protein can result in digestive problems as well as gout, when excess protein is excreted by the kidneys and results in high amounts of uric acid.

Alder Burns wrote: I think that most grains and other dry feeds are labeled as to protein (and other nutrients) as a percent per weight.

Thanks Alder - this is what I was asking and weight basis was my starting assumption but then I got a little confused.  I have not found one single source with information about all the different crops I am looking at so understanding the general conventions vs other specified data listed by different folks is important!  

Interestingly, the amaranth seeds are 13% protein whether you look at % weight or % of total calorie content, whereas the greens are much lower protein based on weight (as I think most greens will be due to high moisture and fiber content as some of you have mentioned).  

Joseph, I did see how you arrived at your numbers and that makes perfect sense as a methodology - just don't know what the general convention is.  Depending on which data I look at, your numbers for other feeds may or may not match up using this same methodology.  For example, looking at the same data source, green peas are listed as 23% protein based on calorie content (close to your 25%) vs only 5.5% based on weight (8g per 145g serving).  Green Peas

Then again, if the peas are dried then they would be closer to the 25% figure you cited.  See this data (same source) re: split peas that appears to be on a dry basis and comes out to about 24% weight basis: Split Peas

My plan is to let the chickens largely self-harvest during the growing season.  Based on the data above, whether the peas are dry or still green/moist at the time I move my chicken paddock onto a patch of peas will impact the amount of protein they get with a full crop.  Not that the nutritional content of each pea will be much different, but the amount of protein per pound of peas (or per unit of volume) will be.  Also it will impact how much water they need to wash it all down, I guess.  

I am not trying to nit pick between one source that says 23% and another that says 25%, but rather to understand whether the correct figure to consider is closer to, say, 10% vs 25%, and especially to make sure I am correctly comparing one feed source with another.  Because everything in my bag of store-bought chicken feed is dried, it is a little more straightforward of a calculation than trying to figure out nutrient density of live feeds in various stages of plant maturity.  

Guerric Kendall wrote:I've noticed that before with amaranth, but never thought it odd?

Both
http://articles.extension.org/pages/67475/feeding-amaranth-to-poultry
and
http://www2.ca.uky.edu/smallflocks/Nutrition-Amaranth.html
Include amaranth leaves as higher in protein than seeds, and both directly relate to chickens, so there's no mistaking it with ruminant percentage.

....Perhaps chicken food is better when it isn't boiled?
.

Thanks - note that the second source specifies a high protein content for dried amaranth leaves.  This is good information but I won't be cutting and drying the leaves so the weight basis protein content of the leaves will be much lower for any leaves I give my chickens.

From a purely filisofical point of view, protein percentages strike me as something of concern to mega-farmers that treat animals as comodities or as cogs in a machine. As a sustenance farmer, it's not feasible for me to know much at all about what the free-range chickens are eating. They eat what they want when they want. Percent protein really only becomes an issue when I am confining the birds to a small cage, and the only food they have access to is what comes out of a commercial feed bag. The more critical question in my mind, is do the birds look healthy? Are they getting sufficient calories, minerals, proteins, and fats to look and act healthy? That information doesn't come from a nutrition label, it comes from careful observation of the birds and their behavior.

Joseph Lofthouse wrote:From a purely filisofical point of view, protein percentages strike me as something of concern to mega-farmers that treat animals as comodities or as cogs in a machine. As a sustenance farmer, it's not feasible for me to know much at all about what the free-range chickens are eating. They eat what they want when they want. Percent protein really only becomes an issue when I am confining the birds to a small cage, and the only food they have access to is what comes out of a commercial feed bag. The more critical question in my mind, is do the birds look healthy? Are they getting sufficient calories, minerals, proteins, and fats to look and act healthy? That information doesn't come from a nutrition label, it comes from careful observation of the birds and their behavior.

Understood.  However, these birds won't be completely free range.  They'll be in paddocks which will have some variety of foods available.  I know protein content will be a big driver of growth rates and laying rates, so having a basic understanding of their needs and what various food sources can provide is important.  

These chickens will have an abundance of low protein feed available, such as grasses, fruits, and berries.  However, I know I can eat greens all day and feel full (maybe not satisfied, but full!), and lose weight at the same time.  I'm not planning a weight loss diet for the chickens, but rather a growth and production diet.  In addition to the greens and fruit, I plan to have some deep mulch areas around the fruit trees and berries so they will be able to scratch for bugs and worms.  But, I plan to plant some higher protein feeds around for them as needed, with varying dates of maturity with the goal of eliminating prepared/store bought food, at least for several months out of the year.  

While I don't plan to make a living from the eggs and meat, I do want them to produce at a solid rate and want to make sure I provide for them well right from the start.    The other part of this is determining which plants will do well on my property with minimal upkeep, so I am considering water needs, ability to self-sow (assuming the chickens don't get ALL the seeds/grains), and ability for the chickens to self-harvest.  If I can turn a 5-10 year learning curve into a 2-3 year learning curve by doing some research, I think that is time well spent.

I appreciate all of your comments and insights.  

Mr. Lofthouse is indeed right, protein content is WAY over-rated.

This started several years ago in the dairy industry and for good reason; then...as it is now...dairy farmers got paid/get paid a premium for high protein content milk. This is because at the creameries milk is now broken down into multiple products. One of the most lucrative is energy drinks. So to get farmers like us to get high protein levels, which take a shift in farming techniques, we switched how we do things.

Now the high protein content aspect of things has saturated all segments of livestock, sadly even the types of livestock that do not require it. I even hear of people with equine trying to find high protein hay when it can be detrimental too them, and my word, sheep farmers who raise them for wool often do not know that high protein makes the wool brittle and prone to breakage. Now granted this thread is about chickens and they need a fair amount of it, but like Mr. Lofthouse, he is incredibly right...protein content is so overrated. Give a ruminant too much protein and they are just going to poo out the excess in liquid form so it is necessarily good. Good nutrition for livestock health is about balance and that is balancing protein with energy, dry matter with vitamins and minerals. If I make it sound simple...it is not I assure you, and I am always adjusting.

Note: I am NOT a dairy farmer, I have sheep, but my family has a working dairy farm.

Another vote for what Joseph said.

What I will add to this discussion is that industrial farming of chicken (where crude protein is an important parameter) is all about turning the most economical combination of corn and soy into the most profitable combination of meat and eggs.  That discussion also belongs someplace other than Permies or BackYard Chickens.

I've recently upsized from a 3-4 bird chicken tractor to a permanent structure capable of housing up to 2dozen birds, and I am managing it on the deep-litter method.  This takes crude protein out of my control, because the chooks are eating whatever they want, and it is my job to make sure that there is plenty of it.  Every day I throw in a couple of 5-gallon buckets made up of fruit, vegetables, deer corn, bread, other grains, and whatever other edibles I can scrounge up.  I also empty the lawn mower bag in the chicken coop, thinking that the deep-litter can never get too deep.  The birds seem to be doing well, and when they start laying in a month or two, I'll let you know how productive they are.  Bottom line, chickens will find the protein they need, as long as they have lots of variety to pick through.  Any animal that is willing to kick through a cow-plop to find some juicy, protein-filled maggots is a survivor.