Why didn't my feet cook down?

[RM44]

I processed four roosters that were 4-5 months old and two old hens that were 3-4 years old. The Roos were mixed breeds, but the laying hens were too (they were EEs).

I cooked all of the feet, necks and extra skin in the same pot for about 3 hours. The younger Roo feet broke down, but the hens' feet are still totally intact after all that cooking. (Hens feet are the blue ones.)

Did they not cook down due to age (3-4 years old instead of 4 months old), or do blue feet seem to cook differently? Did I get any beneficial nutrition out of these feet since they didn't break down?

 

[osbmail]

The older hens feet should be a lot tougher and take longer to break down .I don't think the color matters.As far as the nutrients I don't know about I would guess yes .I alway cut the toes off with scrissors if you cut them right they come off easy .Dont think they hurt anything but makes them easier to look at.