Animals eat minerals because they taste good, but they only taste good when they are needed. I know that sounds like gibberish, but consider this: Appetite for any given mineral is governed by a biological feedback loop that involves taste buds, the cellular tissue concentration of the mineral, and the solubility of that mineral in the feed. When the taste buds are triggered by deficiencies of nutrients in the tissue they are able to recognize the needed nutrients. In this case, solubility equates to palatability - it tastes good if you need it. When the animal reaches satiety for that mineral, it doesn’t “taste good” anymore and they quit eating it.
This is the innate physiological ability of animals that allows them to pick and choose the elements they need from a properly presented, cafeteria-style mineral program. It is this same trait that allows grazing herbivores to balance their ration for energy, protein, and minerals in one 6 to 8 hour grazing cycle — if the proper nutrients are available in the pasture.
When beginning a self-regulated mineral program, it is not uncommon for some animals to consume considerable amounts of certain items. In addition to filling their immediate requirements, animals will also eat to compensate for previous deficiencies; e.g. to replace bone mineral loss or liver reserves. It may take 3 to 6 months for this apparent over-consumption to taper off. If it does not taper off, one needs to check other issues as described below.
Animals will seldom over consume minerals unless forced to do so because of improperly formulated rations or mineral supplements. For example, if there is too much Calcium in a TMR ration, animals will eat excess Phosphorus from a cafeteria-style mineral program, to balance the Ca/P ratio. Consumption of P will go down if some Ca is removed from the force-fed ration. If feeding a TMR along with a cafeteria-style mineral program, it is best to add only about 50 to 75% of the computed amounts of minerals. This allows the animals to fine tune their mineral balance without over
ADE consumption goes up if there are high nitrates, excess protein or basic deficiencies in the feeds or ration, e.g. consumption goes up as hay and forages age and deplete in vitamin content.
BVC and Vitamin C intake increases with stress. Stress can be caused by many situations; including bad weather, extreme high production or performance, relocation, bad water, stray electrical currents, and geo-thermal events.
Iodine consumption increases if nitrates are high, if subjected to stray voltage or geo-magnetic fields, or if they are fed moldy feed.
Animals will often change their mineral consumption overnight in response to ration changes or anticipated weather changes. If consumption changes after stabilizing on the FC system the changes could be caused by changes in seasonal needs or ration changes. e.g. animals frequently take more sulfur when they are building a new hair coat in spring and fall.
There is the possibility that some animals may possess or develop a taste for a particular ingredient. Little weight should be given to that opinion unless and until the other factors listed above are investigated and eliminated.
This item was originally posted to a previous issue of Doc Holliday's blog on 22 August 2019.