Selecting the right supplements for your cows
Choose mineral packages to benefit your cows.
5/23/25
AMES, Iowa – When it comes to choosing the right mineral package for your cows, one size does NOT fit all. Iowa State University extension beef specialist Erika Lundy-Woolfolk said the decision begins with two factors: the stage of production and the current diet.
“With much of the Iowa cow herd now being turned out on pasture, be sure to compare components formulated for early spring, breeding season, or late summer as you consider overall packages,” she said. “Some vitamins, minerals, and other additives provide specific value to this diet.”
For example, during the early, rapid growth stage of cool-season pastures and cover crops, 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,” Lundy-Woolfolk said. “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.”
Copper, cobalt, manganese, zinc, and similar trace minerals have a critical role in reproductive success. Many breeding packages will be formulated to have higher levels of these now than at other times of year.
Lundy-Woolfolk 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,” she said.
Other feed additives can be used to combat nutritional and health challenges In the summer, garlic or IGR might be incorporated as a fly control measure. Another example would be feeding CTC to control anaplasmosis. Summer packages in fescue areas may have additives designed to reduce the impact of fescue toxicosis.
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The Iowa Beef Center at Iowa State University was established in 1996 with the goal of supporting the growth and vitality of the state’s beef cattle industry. It comprises faculty and staff from Iowa State University Extension and Outreach, College of Agriculture and Life Sciences and College of Veterinary Medicine, and works to develop and deliver the latest research-based information regarding the beef cattle industry. For more information about IBC, visit www.iowabeefcenter.org.
Contact:
Erika Lundy-Woolfolk, ISU Extension and Outreach beef specialist, 641-743-8412, ellundy@iastate.edu
