Minerals may be required in only small amounts, but their impact on livestock health and productivity is enormous. For farmers managing cattle, sheep and goats on pasture‑based systems, understanding mineral nutrition is one of the most important steps toward maintaining a healthy, efficient and profitable herd.
Why pasture alone isn’t enough
Pastures provide energy and protein, but mineral levels vary widely depending on the type of soil and its fertility, available plant species, rainfall and the maturity of the pasture. Even lush, green forage can be low in essential minerals.
Deficiencies in a herd often develop slowly and quietly, showing up as poor fertility, weak immune systems, reduced growth rates and higher susceptibility to parasite loads. Because these signs are so subtle, mineral problems often go unnoticed until performance drops.
Key minerals
Beef cattle require many different mineral elements in their diets that are categorized as either macro minerals or trace minerals based on the quantities that are required.
When designing a mineral supplementation program, we need to keep in mind the difference between macro and micro (trace) minerals.
Macro minerals are needed in larger amounts and are usually labeled as a percentage of an animal’s diet, whereas micro or trace minerals are listed as milligrams per kilogram or parts per million.
Macro minerals
1. Sodium Chloride. Salt is the foundation of any mineral program. It regulates water intake, nerve function and overall mineral balance.
2. Magnesium is critical in early spring when fast‑growing grass is low in magnesium. Since cattle and goats are especially vulnerable to grass tetany, providing a high‑magnesium mineral during spring flush is a common preventive strategy. Magnesium can be bitter and not palatable if a lower-quality product is used or if other free-choice salts are available, so make sure to only put out a couple weeks’ worth of mineral at a time and monitor consumption.
3. Calcium is critical to bone health, movement, cardiac muscle contraction, blood clotting and as a component of milk.
4. Phosphorus is often deficient in mature or drought‑stressed forage. Low phosphorus can reduce fertility, milk production and growth.
Trace minerals
1. Selenium supports muscle function, immune health and reproductive performance. Many regions have selenium deficiencies in their soil, so remember to regularly conduct soil testing every three years to keep track of mineral levels.
2. Copper is essential for immunity, reproduction and coat/wool quality. However, species sensitivity varies dramatically, and this is probably one of the biggest challenges in mixed-species grazing.
3. Zinc is a component of many enzymes that are important for immunity, male reproduction and is related to hoof and skin health.
4. Iodine is predominantly needed for the production of thyroid hormones, which play a role in maintaining energy metabolism and is also important to reproductive and productive performance in cattle.
5. Cobalt helps with vitamin B12 synthesis, which is important for ruminant animals.
Different species, different needs
When using mixed-species grazing, keep in mind that different species have different needs and sensitivities. Cattle need higher magnesium and phosphorus in their diets as compared to small ruminants. Copper deficiencies may be common in the soils that they typically graze, as they are are high in iron or sulfur (remember soil testing!) Cattle greatly benefit from seasonally adjusted mineral mixes.
Small ruminants such as sheep are extremely sensitive to copper and require minerals specifically labeled for sheep. Goats have higher copper needs than cattle and are often the ones who will show deficiency signs first through faded coats or issues with parasites. Goats also require more aggressive mineral management than sheep or cattle. These differences make having a single mineral mix difficult in multi-species grazing systems.
Delivery methods
The choices that we have on delivering minerals to our livestock include loose free-choice minerals, mineral blocks or tubs or fortified feed. Loose free-choice minerals are the most flexible to use and it is easier to match them to the needs of the species of livestock you are feeding by allowing the animals to naturally regulate their mineral intake. Blocks or tubs are more convenient and weather-resistant, but come with inconsistent intake. Fortified feeds are useful when feeding grains or pellets and can ensure consistent intake, but pasture-only systems may have a more difficult time utilizing them. Regardless of the method, minerals should be fresh, always protected from the rain and available where animals naturally gather
Don’t forget to plan on doing some forage testing as well. This will allow us to see which minerals are available in the plants that our livestock are grazing. Through testing as well as monitoring animals for deficiency signs and intake of minerals, we can make our mineral programs manageable and keep an eye on our overall herd health.
Minerals can be an important tool in our toolbox to create and support animals who have stronger immunity, better fertility, improved growth and are generally healthier and more resilient. Mineral supplementation is one of the simplest and most cost-effective ways for improving herd performance. If you need any assistance in creating or implementing a mineral supplementation program in your grazing system, you can call your local extension office.
