Grass-fed beef producers need to provide ample amounts of high-quality pasture in a long grazing season, and the cattle still likely won’t perform as well as feedlot-finished animals.

That was the case at Iowa State University, where researchers wanted to find out if grass finishing would result in high-value carcasses if cattle with high marbling genetics grazed well-managed pastures.

Starting May 7 last year, 10 Angus heifers chosen for high marbling potential grazed a high-quality alfalfa-bromegrass pasture. Twelve were placed in a feedlot and finished on a grain-based ration. That diet consisted of 45% corn grain, 32% modified distillers grain, 20% ground hay and a supplement that included monensin. No cattle were implanted or fed hormones or antibiotics.

The grass-fed cattle initially were moved to a fresh paddock every three or four days, and excess forage was harvested to maintain pasture quality. In mid-July, they were given access to the entire 26-acre pasture due to dry conditions. On pasture until Nov. 1, they grazed stockpiled forage the last few weeks.

Like what you're reading? Subscribe to eHay Weekly and get the latest news right to your inbox.

The animals were given shade near the water source, flies were controlled with an insecticide dust bag, and bloat-preventive blocks were offered free choice.

The grain-fed cattle gained 3.44 lbs/day, reaching the 1,000-lb target market weight in 111 days. Gaining 1.98 lbs/day, the grass-fed cattle reached market weight in 177 days. Their carcasses graded 60% Choice compared to 90% Choice for the grain-fed cattle. The fat in the grass-fed carcasses was yellow, which can cause lower grades, say the researchers.

“Consistently producing a high-value carcass from forage-fed cattle is challenging,” they wrote.

More from Hay & Forage Grower:

What Is A Perfect Pasture?

How To Measure Your Forage Pasture

A Weed That's Noxious In the Field, Tasty By The Bale