Choose the Best Supplements for Your Cattle Herd

By Andi Anderson

Selecting the right mineral supplements for cows requires careful planning based on their diet and stage of production. Iowa State University Extension beef specialist Erika Lundy-Woolfolk says the decision is not one-size-fits-all.

“With much of the Iowa cow herd now on pasture, farmers should choose mineral packages suited for early spring, breeding season, or late summer,” she explains. These packages often include vitamins, minerals, and additives designed for specific needs.

During early spring, cool-season grasses and cover crops grow quickly and are high in potassium. However, high potassium can reduce magnesium absorption in cows. To avoid grass tetany—a dangerous condition—extra magnesium is essential during this stage.

As grass matures and potassium levels drop, magnesium supplements become less necessary. This change shows how mineral needs shift with pasture conditions throughout the grazing season.

Trace minerals like copper, cobalt, manganese, and zinc are important during breeding season. “These minerals support reproduction and help cows return to estrus,” says Lundy-Woolfolk. Some breeding supplements also boost vitamin levels for reproductive health.

However, she adds that most fresh-growing forages already contain high levels of vitamins. Unless pastures decline or stored feed is used, additional vitamin supplementation may not be required.

In addition to minerals and vitamins, farmers can consider other seasonal feed additives. For example, garlic or insect growth regulators (IGRs) may help reduce fly pressure in summer.

Cattle in fescue-rich areas might benefit from additives that reduce the effects of fescue toxicosis. Some producers also use chlortetracycline (CTC) to manage health issues like anaplasmosis.

Lundy-Woolfolk emphasizes that understanding seasonal changes, pasture quality, and herd needs helps farmers provide the right nutrition for their cows. This supports health, productivity, and reproductive success year-round.

Photo Credit: iowa-state-university