Muscovies aren't laying

I recently got my first Muscovies and love them... except that they aren't laying. I expected the move to interrupt any laying, but they've been here for one month and we only got two eggs the first week. They're in a mobile pen with free choice whole grains. Should I switch to a "complete laying pellet" for a while? I can't let them free roam for now.

Yes, I doubt they are getting enough nutrition to support egg laying in a mobile pen.

Muscovies are more like geese than other ducks. They really need grass or greens as the bulk of their diet, and are unlikely to thrive on grain or any kind of blend designed for chickens. If you cannot pasture them, I would throw them as many weeds and greens as I could….