Curious about Protein levels

[Sophie/Chicken Whisperer]

Hey poultry folk! I was just thinking about how different feeds have different protein levels (starter is 18-19%, grower is 14-15%, and layer is 16-17%). Does anyone know what the difference is between the feeds that some have higher protein than others? Is it more of certain types of grains, or what?

Thanks!

-A Chicken Lover

 

[Cyprus]

@KikisGirls

It has to do with what the feed is intended for and the targeted age group.

Starter is higher in protein because young chicks grow fast and their bodies need a lot of protein for proper muscle and feather growth.
Grower is lower because it it typically used for growing out broilers. These birds need the 14-15% protein level to maintain amd gain muscle mass. They are not laying eggs, so they don't need extra protein.
Layer is slightly higher in protein because it is formulated for laying hens/pullets. When a bird is lauing their bodies require more protein to produce eggs. Therefore, they need extra protein to make eggs.

Typically the protein level is controlled through the ingredients.

 

[Lady of McCamley]

Protein levels are formulated by the feed companies based on studies done for growth in commercial industry for the different bird types.

Usually, they do a pretty good job determining how a bird grows best as that is the industry's business. (Though it doesn't always translate to the backyard experience).

The 22% to 24% meat bird is to bring Cornish Cross type birds to table within the 6 to 8 weeks required. Finisher slows down the growth to keep the muscles more tender, and the bird size manageable, close to harvest time. Those hybrids have been carefully genetically crossed and selected for essentially mutations that grown incredibly large breast meat, thinner leg bones (as the consumer doesn't want long fat drumsticks), and soft tender meat, with a fast turn around so we can get enough of those chicken nuggets. The high protein allows that fast of growth in muscle.

Game Bird feed is often around 22% to even 28% protein. The game bird type is more muscular in a sinewy way, flightier, and consumes more energy for growth. Turkeys are also typically lumped into this category due to body size and growth requirements.

Starter is typically around 18% protein, sometimes 20% protein, and is medicated (amprolium based) or non-medicated. This is meant for just hatched chicks to point of lay for the commercial layer types.

Layer feed is typically 16% protein, sometimes 18%, or even 20%. It has higher calcium for the needs laying hens require.

All Flock is typically 18% to 20% protein. It is used for mixed ages and poultry types, though a poor choice for commercial broilers. It can be used for more heritage type or dual purpose birds that grow slower. Layers require oyster shell on the side for their calcium needs.

I find it is important to target your breed type. Layer chicks can experience muscular problems and malformations if placed on game bird protein levels as they do not need that much protein for growth.

Likewise a meat bird will do poorly, not coming to proper weight, without the protein levels needed for its massive meat development.

Heritage type breeds are a "slower burn" and can handle the more medium levels with growth.

The big thing is to not put chicks on calcium until and if they are at point of lay (though the commercial hybrid strains, Red Sex Links, etc., often do best if placed on layer at 14 weeks, just before lay).

Lofmc

 

[GC-Raptor]

Does anyone know what the difference is between the feeds that some have higher protein than others? Is it more of certain types of grains, or what?

To make it simple.
Most conventional Non-Organic chicken feed contains 2 major ingredients. Corn and Soy, with some other ingredients like possibly wheat, canola, flax, among others.
Ground Corn averages 8.5% Protein, Soybean meal averages 46% Protein.
Most conventional lower Protein feeds have Corn as the first ingredient and Soy as a third ingredient.
A high Protein feed may have Soy as the first ingredient.
A mid-level feed may have Soybean as second.
So they jumble ingredients more Soy, less Corn for a higher Protein, and vice versa, for a lower Protein. GC

 

[ChickenCanoe]

That's a good answer. To carry the explanation further I'll offer the following.
Thanks to over a century of exhaustive research, we now know the levels of protein and 26 other nutrients that are needed, along with energy and fat levels.
However when it comes to protein, the level listed on the bag and guaranteed analysis tag don't tell the whole story.
The protein % listed on the bag is crude protein. But as you know, protein is made up of amino acids. There are 9 amino acids considered essential for humans. In chickens, there are 13 essential amino acids. Those that can't be formed in the body from other AAs. The levels of each needed are known as well.
As was noted, most grains are low in CP while most legumes are high in CP. However, the main reason vegetarian feeds are paired with both grains/seeds and legumes is that their amino acid profiles compliment each other.
It is possible to have a very high CP % and still be deficient in some essential amino acids. The excesses of non-essential amino acids are then processed by the liver and discarded in the feces contributing to ammonia in the bedding.
Further, not every type of corn or every strain of legume were created equal. Even the same grains from different fields will have different nutrient levels. So as the trainloads of ingredients come into the mill, they are assayed for their respective nutrients and blended accordingly. Even pairing a grain and a legume will still produce a feed deficient in lysine and methionine and possibly other amino acids. Those are then added as synthetic AAs to bring them up to the requirements for the age and type of chicken they are intended to feed.