We were really impressed with the entire nutrient profile and especially the niacin of the Nutrena NatureWise All Flock. I was a bit concerned with the Flock Raiser by Purina since our ducks and geese are out in a very large area surrounded by 330' of Permier 1 electric poultry netting, so they can forage quite a bit. With the Purina Flock Raiser just being the minimum recommended amount and warning about dilution of nutrients (specifically niacin) when combined with foraging or other additives to their diet, I was worried about niacin deficiency. I had also read another thread from a niacin search about Purina Flock Raiser being mixed at area mills and sometimes the niacin content was too low for wataerfowl, depending on the mill's recipe that is mixing or the available nutrient resources.
In our area the difference in price of Purina Flock Raiser and Nutrena NatureWise All Flock is just 5 cents per pound with Purina being the lower price. However, when you add in the cost of Brewer's yeast that I always added for our ducklings, that more than offsets the 5 cent price difference and swings the better price value to Nutrena NatureWise All Flock.
The only remaining issue was that Nutrena NatureWise All Flock is pelleted and the pellets are too large for ducklings until they are 7 weeks of age. We started with Purina All Flock and added Brewer's yeast for our ducklings and goslings, then switched to Nutrena NatureWise Flock Raiser gradually over a couple of weeks so as not to upset their GI systems. We are very pleased how they have progressed and developed and we will begin adding free choice oyster shells as our hens near laying age.