Re: Fresh (or Frozen) Meat Cash & Carry?
 

Nope, ah207 gave the answer earlier:
"Galinha is likely to be old egg laying hen that's come to the end of its...."useful" life.

Frango on the other hand is a young rooster or broiler."

so, Galinha is for stewing or boiling, Frango is for frying, grilling or roasting.

Re: Fresh (or Frozen) Meat Cash & Carry?
 

Yes, it does refer to the age. However, in the food sense (certainly in Portugal, possibly not in Brazil) it is usually Frango when talking about meat no matter how old the chicken was.

Of course, most meat sold is usually younger meat so maybe why you don't see it other than Frango.

There are soups and sauces that use Galina in the name but this also doesn't necessarily mean its old meat.

To make it more confusing, Frango is a masculine word, but doesn't refer to the sex of the Chicken.