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.
