The idea of feeding minerals "free choice" to livestock came about by a need to decrease over-consumption of a liquid supplement containing phosphoric acid, protein, molasses, and other minerals. Upon investigation, it was found that the liquid supplement was being used heavily by the animal as a source of phosphorous. Consequently, we discovered if animals had access to a phosphorous source on a free choice basis, over-consumption of the liquid ceased. We then extended this concept to other vitamins and minerals: if the animal was able to select phosphorous on a free choice basis, perhaps calcium could be selected in the same manner – success!
The next item tested free choice was sodium (Na+), in the form of sodium bicarbonate (NaHCO3). It was feared that salt (NaCl) was not a satisfactory source of Na+ because it is one-third Na+ and two-thirds chloride (Cl-), and chloride was already in excess in most rations. Again, we found great success in our method. In time, potassium, sulfur, silicon, magnesium, vitamins, and trace minerals were added to the list. Finally, there were 16 separate vitamins and minerals fed free choice.
As time passed, a number of competing companies, universities, and professionals took issue with the concept of feeding vitamin and mineral supplements free choice, while many others from the same ranks gave support. Those disputing the effectiveness of the free choice method were primarily at odds with the idea that the animal (specifically cows) was more intelligent concerning daily requirements than once thought. Although, some of the opposition did submit legitimate data supporting their claims, so did those sources supporting the free choice method.
We at Free Choice Enterprises, Ltd. have analyzed thousands of pasture samples in our over fifty years of experience. In some of our tests, animals have consumed more of some elements than the established National Research Council (NRC) standards indicated they required, while other tests showed animals consumed less of other elements. These results provided us with evidence indicating that both support and opposition groups were both right and wrong. There was at least one other possibility, perhaps the cow knew what they required and the NRC did not…
This dilemma continued for many years, until FCE discovered what seems to be a reasonable explanation, which showed both groups could be right. We believe there should be several standards representing the amount of mineral required by the animal based on the protein/energy balance of the ration. If the energy content of the ration is low, the protein requirement is also low, corresponding to reduced mineral requirements. Conversely, if the energy of the ration is high, the protein requirement is also high, corresponding to increased mineral requirements. As a result, there are many variations making at least 15 standards for the amount of mineral required by the cow! It appears the cow knew the energy/protein ratio of its ration and adjusted its mineral intake accordingly.
From our years of research and experience, we have learned a valuable lesson: we must consider the entire ecological system before we criticize the choices of the cow. Now we can present two verifiable “truths” about free choice feeding of vitamins and minerals:
First: The health of the animal is much improved.
Second: The cost per head is half or less than alternative programs.