Cattle Nutrition: Minerals Matter

DR. KATIE MASON 

KNOXVILLE, TENNESSEE 

Minerals are a small, but mighty, nutrient requirement for cattle. These elements cannot be made by the body and they are essential for proper function of the skeletal, immune, and muscular systems. Imagine that the major nutrients, such as carbohydrates and protein, are the bricks in a wall. Minerals can be viewed as the mortar that holds the wall together, playing a supportive role in using those major nutrients. Minerals matter, but it can sometimes be complicated to put your finger on exactly what you need in a mineral program. Mineral availability in pasture and hay forages fluctuates according to the season, fertilizer application, weather conditions, forage species, and other factors. Cattle mineral requirements also fluctuate with growth and stage of production. While cattle get minerals from the diet, we often recommend providing a complete mineral program year-round, just to be sure that minerals are being provided at the appropriate level in the diet. Here are a few considerations when it comes to minerals:

• A complete mineral include macro and micronutrients, whereas trace mineralized salt only provides micronutrients.
• The calcium to phosphorus ratio (Ca:P) in a diet should be somewhere in the range of 1:1 to 4:1, with 1:1 to 1.6:1 being ideal.
• Salt (sodium and chlorine) cannot be stored in the body and must be provided daily. Salt is used in a mineral mixture to both encourage and limit intake.
• High-magnesium mineral is important during times of year when grass tetany is prevalent, like late winter and early spring, especially if you have a spring-calving herd.
• Grasses typically provide an adequate amount of potassium.
• Sulfur is more likely to be in excess than deficient, especially in diets high in distillers grains and corn gluten feed.
• Cobalt, iodine, iron, and manganese are rarely deficient in the diet.
• Copper is the most common deficiency in grazing cattle and can present symptoms similar to fescue toxicosis.
• Selenium is very toxic and should only be used in a premixed form, so as not to exceed the legal limit.
• Zinc absorption is tied closely to copper absorption.

When providing minerals to cattle, make sure that feeders are accessible and full at all times. Cattle should generally consume between 2 and 4 oz. of mineral supplement per day; do not cut premixed minerals with salt as this will alter intake and dilute the amount of mineral consumed. Trace mineral salt is not a complete mineral because it does not contain calcium and phosphorus, and therefore will not meet the needs of your cattle. Minerals should be provided in a complete mixture, rather than “cafeteria style”, to ensure that cattle get the full mineral profile in every bite.

Mineral nutrition is complex, but a critical component in cattle nutritional management programs. For more information see UT Extension PB 1749, “Mineral Nutrition of Beef Cattle.” ∆

DR. KATIE MASON: University of Tennessee