I don't use them, but I believe I've read that the withdrawal for antibiotics is the same number of days that the birds were on the drug.
So if your birds are on terramycin for 10 days, do not eat the eggs for 10 days after they are off the drug. The eggs can be hard cooked and fed back to the flock during the time they are on the drug and the withdrawal time.
I'm not positive about this, because as I said, I don't use any antibiotics. Wes would probably know if you need to have a longer withdrawal period.
Personally, I would give the birds plain yogurt with active cultures for the 10 days after they are off the antibiotics. Antibiotics kill the beneficial flora in the digestive system and the yogurt with active cultures will replace them.
By the way, why are you giving your birds terramycin?