I was in my tsc the other day looking for bigger bags of duck feed and all they had was all flock no specific Purina duck feed. I picked up the dumor brand it was 19.50 for 40 lbs then looked over and saw the nutrena was 17.30 for 40 lbs. I've never used nutrena but I have used the dumor layer feed. My hens seem to go through more of that than they do the Purina or co op brand layer. My pen also has a higher poop smell since they been on it. Any reason not to use the cheaper nutrena over the dumor?