PPM is parts per million. I'm not being smart with you Alan, this is the best way I can think to explain it so it's easy to see in your head. If you divided the bag into one million little piles of equal size :lol: 30 of the piles would represent the amount of copper in the feed. Huge difference between 30 ppm and 10%. 100,000 ppm would equal 10%. That seems like a lot unless you are mixing very small amounts with other feed. I think something like 5-10 ppm in the ration used to be the recomended amount to take care of the copper requirements of beef cattle. You can poison them with copper. Is the forage in your area copper deficient? Maybe somebody who is better on nutrition will stop by to help.