Minerals play an important role in the development and growth of beef cattle. Mineral level requirements in the diet vary depending on the age and stage of development of the animal. Minerals needed in relatively large amounts are macrominerals, and minerals needed in relatively small amounts are micro- or trace minerals. Calcium and phosphorus are two of the most important minerals in beef cattle diets and are considered macrominerals.
Calcium is used in the formation and development of bones and teeth. It also plays a role in nervous system and muscle tissue function. Calcium is mobilized from bone and used by the animal for various body functions. Most well-managed forages have adequate calcium. Legumes tend to have more calcium than grasses. Supplemental grains or mature forages are generally low in calcium. In mineral supplements, calcium is especially important as cows and heifers enter into the calving season, where there is an increased requirement for calcium during lactation.
Phosphorus works in tandem with calcium in bone formation and is a major component of cells. Many forages are naturally lower in phosphorus; however, fertilization with phosphorus-containing fertilizers may increase forage to levels that meet herd nutritional needs. As forages become more mature, the more likely they are to be deficient in phosphorus. Many supplemental feedstuffs contain moderate to high concentrations of phosphorus.
Because calcium and phosphorus work closely together in the body, the correct ratio of calcium to phosphorus is important for growth and reproduction. A high calcium level lowers the calcium-to-phosphorus ratio, decreases phosphorus absorption and results in reduced growth and bone mineralization. A minimum ratio of 1 to 1 is needed. When the ratio is less than 1 to 1, metabolic issues such as grass tetany and milk fever may occur in grazing cattle.
In the southeast U.S., a large majority of mineral requirements can be met from forages and supplemental feedstuffs. Mineral supplementation is the “icing on the cake” to make sure needs are being met as part of the nutrition program. A complete mineral supplement containing both calcium and phosphorus can help ensure mineral needs are met during different times of the forage growing season and the cattle production cycle. Check the mineral tag for ingredient composition, product purpose and information for use.
For more information on selecting a mineral supplement for your operation, download our Alabama Extension publications “The Importance of Mineral Supplementation and Mineral Tags” and “Considerations for Mineral Supplementation in Cow-Calf Operations” at the Alabama Cooperative Extension System website.
