If it is related to niacin, perhaps you can look up the feeds that are available near you on this chart to see which one contains the most niacin before you buy your next bag
https://docs.google.com/spreadsheets/d/1upDVFXEQPK8PUIF6Sj3Bt5CUQfX1PlTEhg799sDT-qM/edit#gid=0
Hopefully with proper nutrition the lameness is reversible, however, since your duck has already done most of its growing, it's hard to say.
https://docs.google.com/spreadsheets/d/1upDVFXEQPK8PUIF6Sj3Bt5CUQfX1PlTEhg799sDT-qM/edit#gid=0
Hopefully with proper nutrition the lameness is reversible, however, since your duck has already done most of its growing, it's hard to say.
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