The Mineral Encyclopedia – Abridged

Minerals are an ever important, but often forgotten nutrient. Found in most feedstuffs and required in such smaller quantities when compared to other nutrients like water, energy, and protein, it’s easy to not keep them at the front of your nutritional plan. Further difficulty lies in keeping all the minerals, their purposes, and the animals needs of each in line. Energy and water are essentially a single nutrient each. While we can dissect protein much further into amino acids – we generally discuss crude protein, or rumen degradable, or undegradable fractions. Minerals, however, are all unique in their requirements and functions, with 15 that serve noteworthy purposes within cattle production. Variable environmental rates and a complicated network of interactions (Figure 1), many of which are antagonistic, results in a difficult task to manage your cowherd’s mineral nutrition plan. While whole books and chapters have been written on this subject – below is an abridged encyclopedia – the what’s what, and who’s who of mineral nutrition for your cattle for those times when you need to review your mineral program annually:

Macro-Minerals

- Calcium is the most abundant mineral in the body. With only 2% of the body calcium not used for structural support, it could appear as though calcium is less of a factor in body physiology. Calcium is also involved in numerous bodily functions from blood clotting, muscle contraction, enzyme activation, and even reproduction. Between bone, lactation, and bodily function, calcium requirements for cattle are calculated by various equations relating to maintenance, growth, lactation status, and gestation. Regardless of the absolute requirement, calcium tends to be one of the most affordable minerals to supplement. It’s major source is from limestone, or calcium carbonate, but many other sources can be seen on tags including calcium sulfate, and even in monocalcium phosphate. - Magnesium is a hot button nutrient for many producers. Found in the skeletal matrix, it is also best known for its role in muscle contraction. Anyone who has experienced a cow with hypomagnesium, or, grass tetany, understands the importance of magnesium in a cow’s diet. Grass typically has sufficient magnesium for most cattle. A mild supplementation can help ensure storage in the body is more than adequate, even for the well discussed spring forage growth. When grasses are youthful and rapidly growing, magnesium levels do not decrease. However, the higher water content results in reduced intake of total magnesium, as well as an increase in potassium. Potassium is a well-known antagonist to magnesium absorption in the rumen, whereby creating the opportunity for decreased magnesium levels to a point of grass tetany. Magnesium oxide is the primary ingredient used for supplemental magnesium, while others including magnesium sulfate may be seen. - Phosphorus is a key macromineral for many functions. Phosphorus is often discussed in combination with calcium due to their joint role in skeletal formation, but the ratio of the two has often been overemphasized in cattle nutrition, particularly in grain-based diets. Beyond bone formation around 20% of the body’s phosphorus is in soft tissues. This includes its use in cell growth, DNA and RNA, energy production, and overall metabolism. As can be seen from the multitude of cell growth components, phosphorus is essential for reproductive success in a cowherd. Phosphorus is a mineral that is typically available in sufficient quantities in grains, but plant tissues like leaves, grasses, and stalks don’t accumulate enough. This is why phosphorus is typically not supplemented to high-grain fed cattle like in dry-lot and feedlot diets but is often a major component of mineral supplementation for a cowherd grazing and consuming primarily fresh and stored forages. When looking to increase dietary phosphorus in forage rich diets, monocalcium phosphate is primary choice for nutritionists and feed companies. - Potassium is the third most abundant mineral in the body and is a major cation second only to sodium, aiding in maintaining osmotic pressure, and water balance, while also playing a role in muscle contractions, nerve signaling, and supporting enzyme reactions. Potassium tends to be more than adequate in grazing cattle diets. During lush, green, and rapidly growing conditions for forages, potassium can increase to a level that is antagonistic to magnesium absorption, sometimes resulting in grass tetany. When cattle are on grain rich diets and potassium supplementation is required, look for supplements with potassium chloride, potassium sulfate, or potassium carbonate, to name a few. - Sodium and Chloride are often discussed together. They are predominantly supplemented together as sodium chloride, or salt. While chlorine requirements are not well defined, deficiencies are unlikely due to the nature of sodium supplementation via sodium chloride salt. Chlorine is an important mineral due to it’s use in stomach acid production (hydrochloric acid), as well as acid-base balance and oxygen and carbon dioxide exchange in the blood. Sodium on the other hand plays a major role as the main cation of the body. Sodium plays part in muscle contraction, nerve signaling, and energy and protein transport across the cell membrane. Ruminants have an appetite for sodium, and as such, it is one method used to manage free-choice supplement consumption. However, cattle will consume more than their requirements if salt is available free choice, hence the art of controlling intake with sodium. Overwhelmingly, the primary source of supplemental sodium and chloride for cattle is salt. - Sulfur is often discussed as an over-abundant or bad mineral. With the onset of, and abundance of corn co-products, sulfur within the diet of most feedlot cattle, and even supplemented cowherds during the winter months, can have an abundance of sulfur above the safe levels (0.4 % dry matter basis). Hydrogen sulfide gas can be readily produced in the rumen, and when levels are high, absorption of hydrogen sulfide can result in polioencephelomalacia. Often associated with thiamine deficiency, sulfur toxicity and polio is not dependent on a combination with thiamine deficiency. Cow not receiving corn co-products still require sulfur, as it is used by the rumen microbes to make sulfur containing amino acids. Proper microbial protein synthesis is essential for cattle nutrition. While many feedstuffs provide sulfur, another common source is that from common inorganic trace mineral sources – trace mineral sulfates.

Micro- (trace) Minerals

- Chromium is intimately involved in energy metabolism. Studies continue to report positive responses of chromium on additional functions as well including protein metabolism and more recently, heat stress mitigation. Largely related to it’s energy pathway involvement by supporting the molecule chromodulin, it helps to increase insulin sensitivity and therefore glucose efficiency. While chromium is known to be a required mineral, the most recent copy of the NAESM (2016) suggests that there is not enough data to support setting a requirement level. Currently, chromium propionate is the only approved source of supplemental chromium for cattle. - Cobalt is a unique trace mineral in that we want it to be used in the rumen. Ruminants do not normally require supplementation of B-Vitamins due to the production of these nutrients by rumen microbes. One of those, essential to energy metabolism, is vitamin B12. Cobalt acts as a co-factor of vitamin B12, and it is estimated that up to 13% of dietary cobalt is used in the rumen for this function. Cobalt is also used throughout the body in other energy and protein related enzyme reactions. Cobalt tends to be found in greater concentrations in legumes like alfalfa and clover, but grasses and feedstuffs in general have difficulty in providing adequate cobalt for today’s cattle. For supplementation, look for the inclusion of the inorganic cobalt carbonate, or organic forms, cobalt glucoheptonate or cobalt proteinate. - Copper plays a role in supporting numerous enzymes. These function across the body in various energy, growth, reproductive, and immune system functions. Copper is well known in black cattle for creating a red-tinged haircoat when it is deficient in the diet. Other symptoms of deficiency include decreased growth and delayed or depressed estrus among others. Deficiency is often discussed with copper due to antagonists that bind and prevent the absorption of dietary copper. A major source of this is a compound made up by molybdenum and sulfur, thiomolybdate. Monitoring the levels of molybdenum and sulfur in the diet of cattle is important, along with supplementing enough copper. Copper oxide is very poorly available to the animal, so look for copper sulfate as an inorganic source, or rumen protected forms such as copper lysine, copper amino acid complex, basic copper chloride, or copper proteinate. - Iodine is most well-known for its role in thyroid hormones and their regulation of energy metabolism in the body. When a mineral is so heavily involved in hormonal energy control, it’s easy to understand the impacts of deficiency range from still born calves to poor semen quality in the reproductive performance of a cowherd. Look for calcium iodate, or ethylenediamine dihydroiodide (EDDI), which both share very similar bioavailability. - Iron is an essential nutrient used in several proteins and enzymes, most notably hemoglobin and myoglobin – those used for oxygen transport and storage in the blood and muscle, respectively. While iron has the greatest requirement of all trace minerals (Table 1), it also tends to be the most available in nature with cereal grains and plant protein meals providing ample iron. Forage is also an abundant source with even greater levels in soil contaminated grasses and hays. Another major source is livestock water, which is often iron rich, many times to the point of antagonistic levels to other trace minerals. When supplemental iron is needed, ferrous sulfate, or ferrous carbonate is often used. Many times, ferrous oxide will be used to maintain a consistent color and look of mineral, with its availability at near zero compared to the more available sources listed above. - Manganese is used predominantly in the body as an enzyme activator and co-factor. Manganese is also the only trace mineral to have differing requirements for grow/finish cattle from reproducing cattle. While many studies have shown no improved growth performance with supplemental manganese, reproductive performance has improved in heifers and cows alike in faster cycling and reduced services per conception. To capture these benefits, look for the inorganic source manganese sulfate, or organic sources including manganese methionine, manganese amino acid complex, manganese proteinate, and manganese polysaccharide complex. - Molybdenum is used in the body as a co-factor for at least three enzymes. However, there is no established level for a requirement. A deficiency is highly unlikely in a normal production environment. However, a major discussion point of molybdenum is that it reacts with sulfur to create an antagonistic compound called thiomolybdate. This compound then binds copper and decreases the copper availability to cattle. Unless looking at a sheep feed or supplement, supplemental molybdenum is highly unlikely in a cattle diet. - Selenium was first described as a substance before it’s recognition as an essential mineral, likely due to its low maximum tolerable level (Table 1). It is an important component of the antioxidant glutathione peroxidase, but also plays several critical roles in energy metabolism, and genetic protein coding. White muscle disease is the most common deficiency symptom but can be prevented by selenium supplementation of the pregnant dam – particularly organic selenium. Selenium yeast has been shown to transfer to the fetus more readily during gestation, making selenium yeasts or selenomethionine good sources for late gestation mineral. Sodium selenite is another source often found in cattle supplements. - Zinc tends to be the most touted trace mineral due to it’s wide use throughout the body. From immune and antioxidant support, energy, and protein metabolism, and directly impacting reproduction via the “zinc spark”, zinc support strong performance in all levels of cattle production. Older studies used to develop requirements suggest a requirement of 30 ppm in the diet across all life stages (Table 1), however more recent studies suggest higher supplemental rates achieve greater growth and performance in feedlot cattle. Look for an inorganic source like zinc sulfate, or organic sources like zinc methionine, zinc amino acid complex, zinc proteinate, or zinc polysaccharide complex. Table 1. Mineral requirements and maximum tolerable levels of beef cattle (Dry Matter Basis)^a

Figure 1. The “mineral wheel” of interactions across minerals.