Any supplementation given to Livestock, is a crutch to help you through a change, be it Environmental or Physical. It is to make sure you do not loose animal performance, while you the manager and animals, are going through a learning curve.
There is increasing evidence, that we humans, particularly since the advent of barbed wire, have managed in such a way that we have reduced the effectiveness of our soils. The result being the plants growing on those soils, do not capture the amount of Energy from the Sun, which used to be captured. The loss of these plants is not as dramatic as we thought it might be, as Nature knew we were going to mess up and the seeds of those good Energy capturing plants are still in and on the soil.
To enable these seeds to germinate and grow, we need to change the Environment at soil surface level. There is no argument, that this can be achieved with livestock, by emulating what happened in the past, before man intervened with a rifle and barbed wire.
Some of the things we have learnt are :-
The bigger the herd, the better the animals do and the quicker the soil is restored.
The more Carbon (plant material) is trodden onto and into the soil, the better the soil does.
We need to manage the livestock to make sure the soil is covered with growing plants or litter, to keep the soil at a more constant temperature and feed life in the soil.
We also know that selection of grazing makes animals perform (fat).
This is all achieved with Time and Timing
"When You Feed a Cow... Watch the Cow... Ian Mitchell-Innes"
You feed the bacteria in the Rumen. The health of the Bacteria, will dictate: Performance, Immunity, General health...
Carbon - pH - Protein - Energy - Water - Minerals