They may not lay year round,
but we have gotten 10 or so eggs and 15 ducklings from one mussie duck this year already!
We just put her back in the adult night pen, so in another 2 weeks or so she should start to lay again, then collect them or wait and get more ducklings in 2 months or so? We have found homes for most of the babies, so we only have 4 culls left to process in a couple of months, so we will probably let her set another clutch. Our chocolate duck sat on 10 eggs and only hatched 3 ducklings and we want another chocolate duck, so we have to keep one of her drakeletts to breed back to her. Will be pretty, but if this is an indication of fertility, not very productive! She did not care for our black drake, but she is very small and he is 20+ lbs! At least we got 3! I guess if you select for fertility, then you could get quite a few eggs from a mussie! Just don't forget that the drake is very important to fertility and egg production of his daughters! At least according to Mr. Holderread! He says that you can breed for up to 125 eggs per year from a muscovy. Just give them warmth and light!
But yes, in a perfect world...
DG