URBANA, Ill. – Although most cattle producers know minerals are important and feed them in various ways to their herds, these essential nutrients play critical roles in immune function, the reproductive system, and growth and development, said Travis Meteer, University of Illinois Extension beef specialist.

“While we talk a lot about mineral needs, the method of delivery is vital to a successful mineral supplementation program,” he said in his July 26 report.

Among some of the most popular mineral methods are free-choice, mineral block, mineral premix for a Total Mixed Ration (TMR), top-dress mineral supplements, liquid minerals, loose minerals, and injectable trace minerals.

With the free-choice method, Meteer said, minerals are offered free choice in a feeder where cattle consume minerals as needed: “This is the most common method of mineral supplementation and is very familiar to producers.

“It provides continuous access to cattle, allowing it to work well in grazing systems,” he added. “It is important to keep in mind that intake can vary among animals, with some consuming too much and some consuming too little. It’s always important to monitor consumption.”

Grant Dewell, DVM, Iowa State University (ISU) associate professor of veterinary medicine and beef extension veterinarian, told Farm World, “Besides adding your mineral program to the daily feed, which isn’t practical in most pasture situations, providing minerals in a free choice feeder is probably the most reliable.

“Although intakes may fluctuate – and it is not the most reliable way to deliver medicated products because of that fluctuation – the cows’ need for salt will have her visiting the feeder often enough to maintain some levels,” he said.

Dewell said, “Loose minerals have more options for adjusting trace minerals levels to fit your circumstances, compared to blocks, and we generally see better consumption with loose minerals. When using a free choice loose salt, make sure the feeders are protected from weather, and refill regularly to maintain adequate intakes.”

Meteer said, “If you feed a TMR (Total Mixed Ration), it is likely that you are already mixing minerals directly into your ration. This allows you to more accurately control intake and deliver minerals to the bite. This method does require you to utilize a TMR feeding system. This is less common in small herds, and less practical for grazing herds on summer pasture.”

He said top-dress mineral supplements can also be included in or applied to the top of daily rations: “With this incorporation, intake consistency is better, and it fits well into diets that are being delivered daily. At the same time, this method is dependent on regular supplementation. If daily feeding is not occurring, this method is not effective.”

While liquid minerals are another way to deliver minerals free choice, he said feeder designs and handling liquid can pose challenges:”

Dewell said, “Liquid supplements or lick tubs do get pretty good consumption, although we do see wider fluctuations between cows that really like the product versus others that visit sparingly. The main deterrent to liquid molasses or protein-based products is the cost.”

Meteer said injectable trace minerals can be delivered via needle and syringe, delivering a known amount to each animal and making it useful before breeding, weaning, transportation or other periods of high stress.

“Any variation from voluntary intake or concerns of bioavailability can be bypassed, because the trace minerals are injected directly into your cattle,” he said. “However, this method does require more labor and cattle handling. An injectable trace mineral is not a complete mineral program, and can add additional costs.”

During the early, rapid growth stage of cool-season pastures and cover crops, Erika Lundy-Woolfolk, ISU beef specialist, said it’s important that cows get extra magnesium: “The vegetative grass is high in potassium, which is antagonistic to magnesium, and without adjusting to fortify the diet, there is a risk of grass tetany,” which is a fatal metabolic disease caused by low-magnesium levels in the blood.

“Once grass growth has slowed and the early cool-season species start to head out, the potassium content drops, and the extra magnesium is no longer needed,” she added.

She said vitamins play an important role in reproduction and a female’s return to estrus, and some breeding packages will boost vitamin levels: “However, most actively growing forages have high vitamin levels, so additional supplementation of vitamins is not warranted unless forage supplies dwindle and stored feed is fed.”

Dewell said, “Adding your mineral mix to the feed is the most reliable way to assure adequate intake across your herd. For non-confinement operations, that mixing with feed can be challenging. But, if possible, during late gestation to make sure the fetus is getting adequate vitamin and mineral levels, it’s worth implementing.”