Blue Swedish Duck hasn't molted primary wing feathers in three years!

[Yoles32]

Hello duck people!
I have a small flock of three ducks that are four years old. Two Black Swedish and one Blue Swedish. The problem is with the Blue Swedish hen. She hasn't molted her primary wing feathers since she grew her adult feathers! So three years later they are just like sticks on the end her wings. She has molted her other feathers, including her tail. This summer she molted most of her body feathers and they grew back nicely. But those primary wing "sticks" are still there!
She also has never stopped laying eggs - no winter break, until this summer when her laying became a bit more sporadic. And she lays mostly softies for the past year and a half, even through the winter and through her molt this summer.
I'm worried about her water-proofness over the winter (we are in NY).
Oh, and on occasion she goes lame and can't walk. This has happened a few times in her life, but the next day she can walk and seems fine.
Any ideas what I might be able to do to encourage the primary wing feathers to molt and to harden up those eggs?
I feed Scratch&Peck organic feed mixed with whole wheat and oats (following Storey's guide to Raising Ducks formulas). I give free choice crushed oyster which she eats a lot.
The other two ducks are normal - healthy, strong-shelled eggs, full molts.
Thanks for any advice.

 

[ducksinvt]

Hello and welcome to BYC!!! Hopefully some of the experts here can help you out, they are pretty great!!! @Isaac 0 @Miss Lydia @casportpony

 

[3bird]

We don't have a good answer to your question, but we do have a potentially related experience.

We have a duck (Martha, three-year old silver appleyard), who didn't molt her primaries for almost three years. Her feathers were not sticks, but they were decidedly frayed and ratty. She is a pretty small duck and has several other odd habits (e.g., when she drinks, she throws her head back and sometimes almost tips over). She's always been spunky, and she's our broodiest girl too, but she's always looked like kind of a mess (a very cute mess!). We named her Martha after Martha Graham because of her "modern dance" moves that early on distinguished her from her siblings. Then all of a sudden, this year she molted, and she looks gorgeous! She also became significantly more confident, and she's even become one of our drake's favorite girls.

To the best of our knowledge, we did nothing different in terms of husbandry, with the exception of putting them back on Mazuri Waterfowl Maintenance (free choice) this past winter. They free-range a couple hours a day year-round. Otherwise they are in a pretty big fenced field. They get "soup" twice a day (peas with greens and a mealworm crumble), and they have free choice oyster shells and egg shells when we have them.

 

[TomCahalan]

I feed Scratch&Peck organic feed mixed with whole wheat and oats

That sounds like a very low protein diet. Try putting them on an 18% feed without the whole wheat and oats mixed in.