I'm on my phone so it's hard to type everything out. Oats are about 10% protein and the feed is 20.5%. If I take 50% (.5) oats, that's 5%. Add the 50% feed and that's 10.25. 15.25%. For the other calculation, 80% (.8) feed is 16.4% plus 20%(.2) for 2 for 18.4%. You have a scale. Weigh...
the easiest solution is to buy the correct feed for now when it's most critical and use the other feed later mixed in a little at a time.
If you have to use it mix it by weight not volume. Mix 2# oats to 8# feed for 18.4%. Mix 1# to 1# for 15%. I would sprinkle the brewers yeast on the...