The Haxtun-Fleming Herald - What can we reason but from what we know? -Alexander Pope

Like all animals, beef cattle need an appropriate amount of minerals to allow for proper body function, lactation and growth. Grazing cattle intake most of their minerals through the forages they eat, but grass and forbs can provide different levels of minerals depending on their growth stage and the soil they grow in. Cattle too have differing levels of mineral requirements depending on their stage of production.

There are 17 minerals cattle require. They are divided into macrominerals: calcium (C), chlorine (Cl), magnesium (Mg), phosphorus (P), potassium (K), sodium (Na) and sulfur (S); and microminerals: chromium (Cr), cobalt (Co), copper (Cu), iodine (I), iron (Fe), manganese (Mn), molybdenum (Mo), nickel (Ni), selenium (Se) and zinc (Zn).

To understand mineral needs, a producer should understand both the cattle’s needs and the mineral content of their forages. There are several resources available that can provide data on cattle mineral requirements and the average mineral content of various grasses and forbs cattle graze. These resources can be helpful to determine the level of minerals provided by the forages being grazed. The key is to be aware that cattle’s mineral needs and the minerals available in their forage changes over time. For example, bred cattle may require .21 percent of their daily ration (on a dry matter basis) of calcium but this increases to .30 percent when they are lactating. Conversely, minerals such as calcium are most available from new growth plants and decrease as plants mature.

Mineral supplements is a solution for providing minerals needed but can easily be a waste of money if the formulation of the supplements does not meet or exceeds the needs of your cattle. Many commercially available mineral mixes have multiple formulations for cattle. For instance, a formulation may be great for bred cows on new growth pastures, but a different formulation should be used for lactating cows on maturing pastures in late summer.

Sometimes cattle can give a producer an obvious sign of a mineral deficiency. Black cattle with hair appearing rough and pale or russet in color may be lacking in copper. One of the most unfortunate mineral deficiencies is low blood magnesium referred to as grass tetany. In the spring, cool season grasses may begin to grow lush and rapidly. If cattle have a low blood magnesium, coupled with the high potassium and protein content of the new growth grasses, a condition known as grass tetany can occur and can result in cattle deaths. (Grasses with high nitrogen content seem to also be associated with low blood magnesium.)

Understanding your cattle’s mineral needs, the mineral content of forages and proper supplementation can be cost effective and lead to optimal production and growth for your herd. As always, if you are concerned about possible mineral deficiencies in your herd, consult with your veterinarian for advisement.