While Idaho is known as the Gem State, the minerals that gave Idaho its nickname are not the same minerals that are needed by cattle. In fact, a University of Idaho surveillance study found that rangeland and irrigated pastures across the state are deficient in zinc, copper and selenium, three minerals that are essential to cattle. With insufficient concentrations of trace minerals found in the forages, supplementation is needed to ensure that cattle’s trace mineral requirements are met.
A trip to the local feed store reveals that mineral supplementation for cattle shouldn’t be an issue with the plethora of options available. While there are plenty to choose from, not all trace mineral packs are created equally. Understanding the differences in the different formulations can help in making sure that cows get what they need. A mineral pack should be assessed on the three following criteria: mineral formulation, concentration of the minerals and estimated intakes.
Mineral formulation
While individual trace minerals are required by the cow, trace minerals are delivered in the feed in the form of salts – each trace mineral is attached to another molecule or substance. There are three major forms of trace mineral salts commercially available: inorganic (trace mineral is attached to other minerals such as sulfates, oxides or chlorides), organic chelates (trace mineral is “chelated” to an organic substance such as an amino acid or yeast) and hydroxy minerals (trace mineral is bound to multiple hydroxyl groups).
The formulation greatly impacts how well the mineral is “protected” in the rumen; the more protected, the better chance the mineral has of being absorbed once it reaches the small intestines. The baseline for which mineral absorption is compared is based on the sulfate forms of minerals. Organic and hydroxy minerals may be absorbed at 150%-200% of the sulfates. However, baseline absorption of minerals is quite low. For example, the estimated absorption of copper sulfate is 5%, meaning that the increased absorption rate of a copper amino acid complex at 150% is still only less than 8%.
Concentration of the mineral
A guaranteed analysis of the mineral levels in a product is required on the tag of all commercially available mineral packs. Macrominerals will be listed as a percent, and trace minerals will be listed as parts per million (ppm). Selenium is regulated by the FDA for a maximum daily consumption by cattle. As a result, the concentration of selenium is set to provide the maximum daily amount of 3 milligrams per head per day. Since not all forms of minerals are absorbed equally, assessing the mineral form along with the concentration is necessary. If organic or hydroxy minerals are in the pack, a reduction of the total concentration of minerals may still provide adequate total intakes.
Consumption
While assessing the concentration of minerals allows the producer to know how much mineral is in each ounce of supplement, the producer also needs to know how much total quantity will be consumed. A concentration of 1,000 ppm consumed at 4 ounces per head per day will provide the same total amount of mineral as 2,000 ppm consumed at 2 ounces per head per day.
In a loose mineral pack, white salt is generally used to regulate the intake of minerals, as sodium is the only mineral a cow is able to self-regulate on consumption. For this reason, cafeteria-style supplementation (where individual minerals are placed in separate feeders and cows choose which mineral to consume) are ineffective. Consumption on this method is based only on palatability of the mineral and not on a cow's needs. Mineral supplements will have a targeted amount of daily consumption listed. Monitoring intakes is as easy as dividing the number of pounds offered by the number of cow days it takes to consume. For example, a 50-pound bag of mineral lasts 10 days when fed to 20 cows (10 days multiplied by 20 cows is 200 cow days). Consumption would be 50 pounds per 200 cow days, or 1/4 pound (4 ounces) per head per day. Placing mineral closer to or further from watering or lounging areas can also influence intakes that are not consistent with manufacturer recommendations.
Single-use products
Ideally, each cow would be able to consume her daily requirement of trace minerals each day. However, not all cows will eat exactly what is needed; some cows will eat more than is needed, some will eat the correct amount and others may not eat any at all. (And this is assuming that supplement is always available and never runs out or gets eaten by wildlife on the summer range!)
Because of this difficulty in ensuring consistent daily consumption, single-use products are available to allow producers to supplement these essential trace minerals when cattle are being handled in the chute. These products are offered as oral drenches, pastes, boluses or injections. While all of these methods allow producers the ability to get trace minerals into the animal, university studies have indicated that only injectable trace minerals are able to rapidly increase trace mineral levels in the blood and liver. As a result of this rapid repletion, cattle are better able to respond to vaccines and have improved reproductive performance by having adequate levels of trace minerals in their systems.
While Idaho’s natural gems bring people from all over seeking these precious minerals, cattle producers must make sure they seek out minerals to supply their cattle with what they need to perform at their best. By taking a few moments to recognize the difference in formulations, either oral loose minerals or single-dose products, producers can find the minerals their cattle need and not just give them ordinary rocks.
