Good morning! Thank you all for a valuable discussions, so many insights! Yes, I did not mention anything about the flock size and type as I did not think it is important. I also did not mention the fact that all my chicken are "homemade" i.e. all are hatched by me so the layers are not the typical production layers (lived in cages, etc.).
Here is some info about the flock, though I would like to focus on some points about the grains.
The flock is a little over 100 birds, with 2-week old chicks to 5-year old hens + some turkeys. I am not counting the pheasants and peafowl as they are only 5. Free-range - they are absolutely free - no cage, no enclosure, no chicken coop; fenced with a 1.5meters fence which they regularly flyover and go in the woods (I live close to an oak tree forest in the mountains), they come back in the evening.
@Perris thank you for the table, I will print it and have it handy!
@U_Stormcrow Thank you for the explanation, except you have a statement in your post which surprised me: "Rice, of course, is even more deficient, and is still nutritionally superior to corn". According to the table above corn is better than rice? or I am missing something, I guess - rice or corn?
Triticale - it is not just my experience - all over my region where triticale is used instead of wheat, chicken are not well. Additionally, as per the little information available about it - it slows down the growth of chicken and is not good for chicks under 2 months of age. With layers - less eggs. It is gluten-free which I don't know if it is good or bad for the chicken.
@centrarchid - so you are not concerned about the oats negatives, such as: high beta-glucan levels (mentioned by
@U_Stormcrow) or these levels are reduced when oats is soaked as you say - not less than 48 hours, etc. etc.?
@saysfaa thank you for the suggestion, but growing own grain for a large flock is not an option in my environment - too many obstacles, which I will not go into.
So from all comments, I may be wrong, but it sounds like wheat is the best GRAIN for chicken? Soybean - not produced and not imported in the country, (I have searched for that).
We have rice, oats, barley, corn - all at the same price.
Today I am buying Cockspur grass seeds (cheap and available) and I will be adding them to the diet.