Flush free doesn’t work for ducks.
Also I don’t know if the other one is also flush free? or time release ? time release niacin also does not work for Ducks
It goes through their system too fast to release anything.
Did you ever try adding a tablespoon of nutritional yeast for one cup of duck food?
I always do that when they’re little and occasionally when they’re older.
There is a liquid B complex they sell at Feed stores like tractor supply also online like Amazon that I stand by for getting niacin into a duck quickly and a good amount of it .
Not to be used forever daily, but it’s good when it’s needed can be used for several weeks once a day , whenever there is a problem that might be helped by niacin supplementation . I’ll post a picture in case you want to get some.
It says injectable, however
We give it orally with a syringe following the instructions in this link one ML once a day
https://www.backyardchickens.com/ar...dications-to-all-poultry-and-waterfowl.73335/View attachment 4308193