Mine is 28%. Only one store around here carries that - the rest carry 22%. So I go out of my way to the store that carries the 28% because I like to give them a really good start.
Yes, muscovies fly quite well. Mine free-range and we have a pond halfway down our property. They regularly fly back and forth to the pond. Our west border is a hedgerow where the trees are 20+ feet tall. One day last fall my neighbor on that side came over to show me a photo of a duck on her phone, asking if it was mine. Yup - a muscovy duck made it over the hedgerow and was on their pond over there. Like Arielle's, mine are not handleable so there was nothing I could do to get her back except hope she figured it out. I did try but all she did was fly out and land in the middle of their pond and no way was I going out there to get her! Next day she was back and as far as I know has never made that mistake again.
They are really huge birds and it is amazing to watch them take off and fly as it looks like it should be impossible. Especially the drakes.
Yes, they do roost, but not all of them. I have a couple of ducks that will regularly sleep on the roosts - the drakes and other ducks just sleep on the floor of the coop. However I also have one duck who will jump up to lay her eggs in the nest boxes.
I do not like to pen birds period. I have a few small pens that I use when transitioning chicks outside from the brooder, or when a broody hen has just hatched chicks, to give the new family a few days to bond. And I have a hoop coop that I use for short-term projects where I want to collect eggs from a particular pairing. I put the rooster/tom/drake with the appropriate females in there just long enough to gather the eggs I need and then they are let out again. Other than that, all of my birds sleep in the same coop at night and free-range the same property by day. The muscovies do well at staying home. Other than the one mistake last fall, they've never left - just wander around our property, fly to the pond, fly back to the coop for the night….and so on.
Nine months of the year I am fond of muscovies. They are terrific meat birds, good broodies, good mothers and, during laying season, good layers. Unfortunately, laying season is only about half the year and the rest of the time I am feeding them and not getting any eggs. And in winter they're a pain because they are ducks and therefore…..like to bathe. Most of the year I have a gravity waterer for all the birds and if the ducks want more than that they can fly to the pond. But in winter the pond freezes over so they quit going down there. Meanwhile, I have to plug in a heated dog water bowl in order to provide water for the birds. And, I have to haul water as I can't leave hoses out in winter either. So it is especially annoying to haul water down there from the house, clean out and refill a heated 1-gallon dog water bowl and turn around a moment later to find a duck sitting in the bowl (too big so they take up the whole thing) happily splashing all my hard-won water out onto the ground where it can turn into ice, making it treacherous for everyone. Somewhere around mid-winter every year I decide I'm done with ducks and will butcher all of them. Then I think "well, I've fed them this long since they last laid and they'll be laying again soon…..I may as well do one more year and butcher them next fall". Well, you know how that line of thinking goes, so every year I still have them.