I have read of adding cayenne pepper and garlic, but I have not done so for a special cold weather diet. I do feed my ducks garlic often, but never cayenne. Plus I sort of think that they should know best how to regulate their own metabolisms/body temps (much better than me anyway!). I do agree...
19'F is not so bad. Right now my ducks are in -2'F plus rotten wicked cold winds. I do have them locked up inside the unheated barn with a heat lamp, but if my temps were 19'F, I would not worry, as long as the ducks have a dry, draft-free shelter with deep bedding to get into. If you normally...