I have been using the Free Choice Enterprises cafeteria-style minerals for more than 15 years with very good results in many different environments, with big and small herds.
To get the best results, however, there are three things which must be correct up front.
First, mineral and other nutrients absorption is determined by many different factors, one being the pH in the rumen. In turn, that is affected by the water cattle drink, by the ratio of protein to energy and by the culture of bacteria in the rumen.
Since water is more than 78% of the cow’s body, water quality has much to say in the pH of the rumen fluid. It is important to have good-quality water to have the best results.
Second, protein-to-energy ratio impacts mineral and nutrients absorption because when there is a protein excess there is ammonia released. Since it is very alkaline, it raises the pH of the rumen fluid making most minerals not very available. This is why cattle on high-protein diets require more minerals. In truth, it means that a bigger portion of those minerals end up in the manure.
Third, the culture of bacteria in the rumen can have great effect. When we feed grains or starches or sugars (such as molasses) they promote bacteria that produce lactic acid as their waste. This lactic acid, besides inhibiting the bacteria that digest forages, lowers the pH of the rumen, rendering many minerals unavailable.
That is why it is so important to first check the water, then make sure our grazing management is correct so there are no big imbalances of protein in relation to energy, and to not use grains, starches or sugars in large quantities. This is more important when our cattle rely more on grazing but it's also essential in confinement situations.
Once we cover these three bases, our free-choice, cafeteria-style mineral program can work like it was designed to.
It will work also when we do not take care of these three factors but will become expensive. The same happens when we offer the cows a mixed mineral, plus it may or may not be what each cow needs or what our ranch or each specific paddock requires.
With the free-choice, cafeteria-style minerals on offer, each animal can select what he/she needs. Those requirements will vary with class of animal, stage of production or reproduction, water source, grass species, soil in a paddock, and even color of the hair coat.
There are ratios between minerals that have to be correct so the animal can be efficient in his use of nutrients and more importantly to be able to create antibodies to combat specific infections.
When offered this program for the first time, cows will usually consume a lot of some mineral until they become satisfied. It takes up to three months to replenish reserves which have been depleted. It will take the same time to deplete their reserves if animals are not fed the right minerals.
Some of the differences one can observe from a well-operated, free-choice mineral program are: shine of coat, vivacity, better health, improved body condition, fertility, and feed efficiency.
And please remember that one has to correct all of the three factors I described above to achieve optimum results with a free-choice mineral program.