Worms Eat Away at Beef Producers' Profits

Worms Eat Away at Beef Producers' Profits

Deworming beef cattle while grazing pays off in the feedlot.

Beef cattle producers can gain $40 per head when they control worms in cattle that are on pasture, according to a recent study by Iowa State University.

The study showed that deworming stockers or preconditioned calves while they are grazing and before sending them to a feedlot provided a better payout for beef cattle producers.

The research
In one trial, 43 steers from Southeastern states varying in age and weight were shipped to a southwest Iowa feedyard, where fecal samples guided a division of cattle into high (HI) and low (LO) parasite burdens. All were treated with the recommended dose of eprinomectin to control what were 92% roundworms (strongyles).

INVEST IN HEALTH: Beef producers may invest in high-quality genetics, feed and nutritional supplements, but those may not pay off without strategic parasite control, they conclude.

“These parasites live in the digestive tracts, where they cause damage to the stomach, steal nutrients and produce a loss in digestive ability,” says ISU Extension lead researcher Chris Clark.

After 24 days, another fecal exam showed all cattle were free of parasites, but effects of the initial parasite burden were still visible, he notes.

They were all gaining at the same rate by then, but the HI group, lighter on arrival and set back in the first weeks, never caught up. They required more days on feed than the LO group and the HI steers tended to have lower marbling scores, dressing percentages, internal fat and backfat at harvest. Being treated for clinical disease more times, the HI side also incurred higher health costs.

Protect your profits
Even a relatively small research trial serves to point out how easily profitability can be decreased, and reinforces the value of effective internal parasite control starting months before the cattle go into a feedyard.

Clark says the Southeast region, source of calves in the study, is known for high internal parasite risk because of long grazing seasons and a warm, humid climate. Still, he says, grazing cattle across the U.S. are at risk of infection from many different parasites and producers should have a strategic deworming plan that fits their operation.


Patrick Gunn, ISU Extension cow-calf specialist, says timing is the first step in strategy.

Producers often deworm cattle before pasture turnout and again when they come off grass, says Gunn. But until the last year or two, most of the deworming agents available on the market were only effective for approximately 30 days. That means the effectiveness of the deworming agents often wear off just as cattle begin picking up a significant parasite load.

Gunn recommends waiting to deworm until after cattle have been on grass for six to eight weeks, or using one of the recently developed extended-release dewormers. Producers in warmer climates should also look into more aggressive deworming plans with a mid-season option if they graze cattle for longer seasons.

Pasture health and rotational grazing play a role in effective parasite management, Gunn explains. Overgrazed pastures tend to result in higher parasite loads for cattle, so good pasture management can lead to healthier cattle.

Impacts in the industry
The study showed HI cattle made $40 less in total income due mainly to higher treatment and feed costs, and a reduction in carcass quality leading to lost premiums. The cost to deworm a 500-pound calf once is $2 to $6 and, according to earlier ISU research, the largest return on investment in pharmaceutical technology for cow-calf and stocker operations.

Producers may invest in high-quality genetics, feed and nutritional supplements, but those may not pay off without strategic parasite control, they conclude.

Source: Certified Angus Beef

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.