How much protein is too much?

[ctc084]

Hello,

I'm considering adjusting the feed I'm giving to my mixed standards and bantams flock from one containing 18% base protein to one with 20% or 22%. I'm getting mixed reviews while researching. What do you armchair experts believe?

 

[QueenMisha]

Until you get into super high levels (27, 28, 30% or more), I always say the more protein, the better. I keep most of my birds on a 22% turkey/broiler grower ration year round, since I run a mixed pen of about 6 species. It supplements my laying hens very well, and grows my meat birds.

 

[ctc084]

Until you get into super high levels (27, 28, 30% or more), I always say the more protein, the better. I keep most of my birds on a 22% turkey/broiler grower ration year round, since I run a mixed pen of about 6 species. It supplements my laying hens very well, and grows my meat birds.

Thanks for your reply. The molt just started hitting my layers and I'll get them as much help as I can with a little extra protein.

 

[ChickenCanoe]

Usually 18% is sufficient for breeding birds but while molting, they can definitely benefit from 20-22% to build that new winter coat which is 93% protein.
That said, 2% difference in protein is significant so I'd still stay away from anything higher for adult birds.
Another thing to consider is that it isn't just a matter of crude protein % but the makeup in essential amino acids. All 22 amino acids are necessary for muscle deposition but there are 13 amino acids essential to chickens. They can make up the non-essentials from those 13. So protein can be high but still barely enough of one of those essentials like methionine or lysine and the latter two can be used up making the missing ones and still be deficient.
All amino acids aren't required in the same quantities. The amino acid profile is usually not supplied in a high crude protein diet in line with the nutrient requirement of the animal. Not all of the protein supplied will be used and the excess is discarded as nitrogen becoming ammonia in the bedding. It also places stress on the liver to process that excess. Surplus protein is also used by pathogenic bacteria in the large intestine and can cause digestive disorders.
The amino acid that is present in the diet in the lowest concentration relative to its requirement is known as the first limiting amino acid.
In poultry, methionine is the first limiting amino acid, lysine the second and threonine the third referencing their presence in vegetative protein sources.
So rather than go with a feed that is significantly higher in protein, it may be better to supplement some animal protein occasionally.

http://passel.unl.edu/pages/informa...rmationmodule=1017786502&topicorder=3&maxto=7

http://www.hyline.com/aspx/redbook/redbook.aspx?s=6&p=38

http://www.ncbi.nlm.nih.gov/pubmed/21491247

 

[song of joy]

I've been using Purina Flock Raiser (20% protein) for over a year, and my hens are doing very well on it. Some individuals in my flock are continuing to lay eggs while also molting, which had never happened in past years when I was feeding them layer ration (16% protein). They also free-range, so it's impossible to say what their overall protein consumption is. The 20% protein in the feed may be reduced by all of the green vegetation they're eating. On the other hand, they're also eating insects in the spring, summer and fall. Anyway, the combination of a higher-protein commercial feed along with free-ranging seems to be working very well.

 

[Egghead_Jr]

I wouldn't mind an 18% protein feed for adult birds. I don't believe (as no personal empirical evidence) that 16% feeds are adequate. Where I use to live the turkey/pheasant feed was 18% as was the starter/grower. In my new location the local feed is 20% protein for starter/grower and 20% in Turkey Finisher. (I switch back and forth from crumbles to pellets depending on age/size of smallest birds). Many old timers promote extra protein for growing birds and when in molt. That wee bit of extra protein for adult birds when they don't really need it doesn't seem to be hurting them any.

Ideally a 22-24% for growing birds and 18% for layers would be my personal goal. The problem with that is I don't want to keep several different feeds at all times for a multiaged flock. Higher costs involved for the extra levels of protein that adult birds don't need so keeping things simple works for me. Really like the idea of 20% for all birds and they all get crumbles (starter/grower) until the last hatched are 12 weeks old then they all switch over to 20% protein pellet (Turkey Finisher). I buy oyster shell in bulk and toss a few handfuls a week in the run where layers are. As simple as it gets.

 

[Ridgerunner]

Then you get the other end of it. Avian gout for example.

I used to give a different reference but now you have to register to look at it. I’ll include it if someone wants to go to that much trouble but I generally don’t register online. http://en.engormix.com/MA-poultry-i.../avian-gout-causes-treatment-t1246/165-p0.htm

The one I’ll talk about is this British Study.

British Study – Calcium and Protein
http://www.2ndchance.info/goutGuoHighProtein+Ca.pdf

The chicks used were Layer chicks, not Broilers like a lot of the studies I’ve seen. The units in that study are a bit challenging but the best I can figure:

Low Calcium = somewhere around 1%, similar to Starter or Grower
High Calcium = somewhere around 4%, similar to Layer

Low Protein = 16%, like Layer
High Protein = 22.4%, like some Starters.

Adding the calcium makes it a bit confusing, but they ran four conditions, LC-LP, LC-HP, HC-LP, and HC-HP. As you would expect the High Calcium is bad for growing chicks in any case. The High Protein with low calcium didn’t seem to have serious bad effects but combined with the high calcium it was really bad. So calcium is more important than protein.

They keep referring to a Hocking 1989 study. Others are better at research than I am but the only study I found concerned breeder broiler males and ostriches. I didn’t get too far into that one. From what they said Hocking found high protein levels to be detrimental and could cause gout. I’m not sure what they mean by high protein levels, from other reading I get the feeling they are talking about the 30% protein range, not 22%.

I’ve tried to read up on it but I’m not a medical expert and some of this is rough sledding. My general feel is that 22% and even 24% (especially when they are very young) is not detrimental but avoid the 30% range. How long they eat at those levels as an effect too. And as Song of Joy mentioned, what else they are eating to water it down has an effect too. One bite won’t kill them, it’s the sustained diet that might do harm. It’s total protein eaten in a day over a period of days, not what is in one bite.

There’s something else that is purely my opinion, no real research to back it up, but it is proven that the more protein they eat the bigger the egg will be. That part’s not opinion, it’s fact, more protein = bigger eggs. My wife gave natural birth to a 10-1/2 pound baby boy. The doctor was really surprised, he expected at most 9 pounds. She also gave natural birth to a couple in the 8 pound range. She enjoyed the 8 pound range much better than the 10-1/2 pound, especially in recovery. My opinion is that I don’t want my hens laying overly large eggs. I’ve never had a hen prolapse, become egg-bound, or internal lay. Is there a correlation to this and me feeding lower protein levels? I don’t know.

I’ve also read that higher protein levels can cause some hens, especially the commercial layers and really good layers, to release more than one egg yolk a day to form an egg. This can lead to double yolked eggs or a hen laying more than one egg a day. Sometimes eggs can be deformed if you have two in the shell gland at the same time. Often the second egg is soft-shelled or thin shelled because the shell gland doesn’t make enough material in a day to properly cover two eggs. In any case, I don’t consider a double yolked egg or a soft shelled egg a good thing. I’d prefer a regular egg.

Ctc084 you asked for opinions. My opinion is that a protein diet in the range you are talking about will not put them at risk for gout or such, but I would be careful of the increase in egg size or the potential for egg laying problems. I’d stop at 20%, no higher.

 

[ctc084]

Thanks again for all the opinions. They have made for great reading, I won't at all pretend I understand every word in the shared links but I'll fall to the safe side on this and stick right around 20%.

Thanks again for your time folks.

 

[song of joy]

There’s something else that is purely my opinion, no real research to back it up, but it is proven that the more protein they eat the bigger the egg will be. That part’s not opinion, it’s fact, more protein = bigger eggs.

Wow - I didn't know that! Thanks for sharing. I'd also read recently (on BYC, with literature citations) that the higher calcium levels in layer feed can lead to decreased fertility and increased mortality in roosters. That's another important consideration, especially if a rooster is being kept in the flock for breeding purposes.

 

[ChickenCanoe]

Ridgerunner always has good reads.

As for calcium and roosters, you're right on both counts. Excess calcium affects sperm motility and causes renal failure. Renal failure = early mortality.

I can provide the research if you would like.