Managing Mineral Imbalances in Cattle


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Proactively testing and balancing rations to help address clinical signs before they appear is key to proper mineral nutrition in cattle, experts say.

Mineral deficiencies can appear in sneaky ways: more respiratory illnesses or lower breed back rates. Most producers rely on balanced rations to contain the right mix of minerals and avoid costly losses, but that’s only part of the solution. Appropriate mineral combinations and proper inclusion rates ensure adequate supplementation levels are met and can help reduce mineral interactions that may cause minerals to be less available to cattle.

Deficiencies may be more widespread than most producers realize. A nine-year study of Canadian cattle showed:1

  • 47.2% were lacking copper
  • 15.1% were deficient in iron
  • 13% were lacking manganese
  • 10.8% were deficient in magnesium

Signs of deficiency

Examples of mineral deficiencies may be a rough hair coat (associated with copper) or retained placenta and increased open rates (related to zinc). Unfortunately, mineral deficiencies may be at a critical level by the time such signs are visible, explained Angela R. Boyer, Ph.D., senior technical service manager, Phibro Animal Health.

In her work, Boyer consults with cattle producers to identify and rectify mineral challenges. She advises proactively testing and balancing rations to help address clinical signs before they appear.

“We can’t always see the immune health of the animal, but we can see the clinical signs,” she said. “By the time we see that the animal is already negatively impacted in several areas.”

Subclinical signs can include profit killers like increases in mastitis cases, elevated somatic cell counts (SCC), or more respiratory illnesses.

“Once you start to see an increase in clinical signs of mineral deficiencies, it may take up to 60 to 90 days to get the herd’s mineral levels back on track because the deficiencies may have been going on for at least the same amount of time,” Boyer said.

Pinpointing whether the issue is a mineral deficiency, a result of other causes, or a combination can be difficult. The first step is to test the diet. Tests are often done with an evaluation of the overall nutrient profile, which can change from year to year based on forage and commodity changes.

“We are not necessarily testing for the exact trace mineral component,” Boyer said. “For example, if we put ten parts per million of magnesium in the diet, we have confidence it’s in there. However, dietary components such as heavy metals and other antagonistic elements may be present. These negatively impact mineral absorption, keeping essential minerals from being available to the animal. This is critical for the nutritionist to account for when balancing the animal’s mineral requirements.”

Map of Selenium levels in Counties of the Conterminous United States.
Selenium in Counties of the Conterminous States

Growing conditions

First, Boyer evaluates feed sources. Growing conditions of forages and grains within a specific field can influence their mineral composition.

“We tested silage grown on fields next to an old armory that closed several decades ago. The field had high levels of heavy metals and other contaminants,” she said. “Testing minerals and the components of soil and forages helped us create a complete, nutritious diet. With a combination of organic and inorganic minerals, along with amino acid balancing, we were able to reverse the cow’s blood work within 60 days of incorporating the new mineral and amino acid combinations. Overall, we can’t change where our land is, but we can attempt to manage what we’re getting off that land.”

Certain geographic regions and commodities have known mineral deficiencies. For example, there are known areas with selenium deficiencies in the United States. Supplementation may be required when growing feedstuffs in, or sourcing from, these areas.

Consider the operation’s water source as well, Boyer cautioned. While the water source typically cannot be changed, the mineral profile of the water can be accounted for in the total diet requirements.

“Once producers and nutritionists are aware of what is in their water source, they can accommodate any issues or concerns by manipulating the total diet with the addition of organic minerals and/or amino acid balancing – similar to how we balance the ration for forage and grain changes. Cattle – especially lactating cattle – can drink upwards of 30 to 50 gallons of water per day, and even more during heat-stress conditions. Water is a key component in their daily diet; it’s critical to test its nutrient profile, too.”

Organic and inorganic sources

Organic minerals are manufactured in a way that bypasses typical biological interactions that may tie up their availability to the animal. These minerals are bound to an amino acid, proteinate, polysaccharide, or another organic molecule, according to Adele Harty, former South Dakota State University Extension cow/calf field specialist.2

The bioavailability of organic minerals is improved compared to inorganic mineral sources. However, the cost of organic minerals is typically higher, too. Some producers may choose to incorporate organic minerals during periods of high stress, like weaning, to help lower costs but ensure the animals are meeting their mineral requirements.

Inorganic minerals are usually more cost-effective for producers but may be susceptible to interactions with heavy metals and other antagonistic elements. If the minerals are being excreted instead of absorbed, they aren’t available for the cow to use. It’s wasted money, Boyer advises.

“The livestock industry as a whole has embraced organic trace minerals as a tool to help them achieve proper mineral status,” she said. “They’ve seen that meeting mineral requirements can help improve animal performance and production measures. There’s no way a producer could afford to include organic minerals at 100% of their mineral requirements, but we’ve found, on average, a 25% inclusion achieves performance and keeps the diet cost-effective.”


1 Perdrizet U, Blakley B, Al Dissi A. Concentrations and deficiencies of minerals in cattle submitted to a diagnostic laboratory in Saskatchewan from 2003-2012: A retrospective study. Can Vet J. 2020;61(1):57-62.

2 Harty A. Cow mineral nutrition: reading the tag and bioavailability. SDSU Extension. Updated Sept. 9, 2022. Available at:


Key Minerals for Cattle:

  • Zinc is required for protein synthesis, immune support and reproduction
  • Manganese is required for bone growth and cartilage synthesis
  • Copper is required for red blood cell production
  • Iron is required for oxygen transport and energy metabolism
  • Chromium is a response mineral that can help improve performance measures by increasing glucose utilization


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Photo credit: United States Geological Survey