I have just finished reviewing a trace-mineral premix formula for an integrator who is buying his premixes from a nutrition supplier. The integrator only specifies the nutrient levels and the supplier provides the different salts mixed up in appropriate proportions along with a carrier. This is quite normal in most cases I have reviewed.
But, not for the first time, I noticed that copper oxide was used as the only source for copper in the premix.
Now, it is not widely know, but it is very well documented, that copper oxide (unless it is of pharmaceutical grade) has practically zero bioavailability for all monogastric animals. This is textbook information! So, adding copper oxide is like adding ‘nothing’.
So, why animals don’t suffer from copper deficiency? In fact they do, but rarely and only marginally. The reason being that most natural ingredients contain enough copper (a typical diet based on maize and soybean meal contains about 8-10 ppm natural copper) to meet their daily needs.
I would be interested to know how prevalent is the use of copper oxide in the different countries around the world?