I think it was this thread we were discussing a few days ago (can't seem to find it now) about the pros/cons of fermenting feed that has Fertrell Nutribalancer (or another similar premix). From the horses mouth, the animal nutritionist at Fertrell, Don Brubaker:
"I would not put our Poultry Nutri-Balancer through the fermentation process. I feel that it would be best to add it just before feeding at a rate of 3% of what ever you are feeding."
I've since asked him why he recommends this and am waiting his response. I mean, I imagine that the fermentation process improves nutrition possibly even better than such a supplement, but I'd hate to be wasting money IF (big if, as in, I don't have the answer yet) getting the supplement wet negates the vitamins.
Stay tuned...
I have written to them, too! They haven't answered me yet, but I am expecting very much this answer.
(For me, this is another reason, along with what I consider to be a questionable protein source & some overly "precious" customer service attitudes, for not buying certain brands of feed that already have NutriBalancer mixed in. What I do is stir NutriBalancer into my daily serving of Fermented Feed just before the feed bucket heads out to the coop. I'm using a bit less than the full 3%, and I offer calcium on the side. I started doing this at the same time I started fermenting some of their feed because my already-rough-looking flock went into a simultaneous and hideous molt ... and boy is my flock looking and ACTING so much better now! SO much better!)
As I stated before, I believe this is due to the way water soluble vitamins lose potency when exposed to moisture. For example, if you grind up a niacin pill to add to drinking water for ducks, then the water will have to be changed at least every 24 hours, and new niacin ground up & dissolved into it, to keep the potency of the niacin close to adequate. You even have to ingest water soluble vitamins "every day" to keep enough of them in your system because your body flushes them out ...
This is why it is so much harder to overdose on water soluble vitamins.
BK has made a very good point, several times, about the increased nutrition of properly fermented feeds ... about how much the niacin (specifically) is increased in properly fermented corn ... so presuming we are fermenting our feeds properly, then there is less need for (at least some) supplements. If I hadn't been in such a panic about the state of the flock, I would have started with Fermented Feed first, and then added supplements if I didn't feel the birds responded well enough with "just" that.
I think this is a very interesting facet of the discussion of fermented feeds ... how to best use our ingredients to get the most nutritious results for the birds.