Cockerel with weak legs
5% Protein ration is not enough protein for his general health and well being.
I would feed him an all flock/flock raiser poultry feed that has atleast 18-20% protein. These formulas also have essential vitamins/minerals and amino acids.
Limit his treats to no more than 10% of his daily intake until his strength has improved.
I would also get some poultry vitamins to add to his water once or twice a week - something that has the B vitamins, such as Nutri-Drench or Durvet. If he won't drink the vitamin water you can use some to mix in with his feed to make it into a mash.
Hopefully with proper nutrition he will be able to gain his strength and do just fine.
Just my opinion
No problem I was wondering if 5% was possible, but you never know...
He's a handsome boy!
Was he born with the curled toes or did he develop that later on? What was the timeline on that? Did he ever walk "normally" with no problems?
Did the nutri drench seem to help with the curled toes?
What does his poo look like?
Has he been wormed?
I made a mistake thinking the Nutri-Drench has B vitamins (it is a good product though). Durvet http://www.durvet.com/index.php%3Foption%3Dcom_k2%26view%3Ditem%26id%3D99:vitamins-and-electrolytes has the B vitamins, that said, if he were mine I would add vitamins back to his water and see if there is any improvement.
He still may need some extra protein, so you could give him some scrambled/hard boiled egg, tuna, salmon or meat to give him a little boost.
I have a mixed flock as well (cockerel with pullets) and prefer the extra protein provided in the flock raiser/all flock type feeds. They all can eat this with no problem, just make sure you have oyster shells offered for the girls. (This is just my preference).