Should I give chicken extra vitamins?

[Chicks Galore3]

I know that you need to give some breeds of meat chickens something special (Vitamins or something.) so that their legs can support their weight. I have a BIG buff orpington, 8 pounds I think. Should I give her anything to help her walk better? she kinda waddles/runs funny.

 

[chfite]

I give my chickens only Dumor feed and whatever they find in the yard during the day. I have a Buff hen and a rather large Barred Rock rooster. They seem to do just fine without supplementation.

Chris