“Cattle just don’t gain.”

Missy Bonds’ analysis of cattle infested with parasites describes the damage the tiny creatures can have on all cattle. Thus, she’s a firm believer in dewormers and their value in a cow-calf or stocker program.

“The $5-$10/head cost of deworming a cow and calf at branding can mean an extra 50 lbs. for the calf, and better body condition and breed-back on the cow,” Bonds says. Her family’s Bonds Ranch, headquartered in Saginaw, TX, has a detailed parasite control program for its wide range of locations.

The sprawling operation includes pastures in 26 Texas counties, as well as Oklahoma, Kansas, New Mexico, Colorado, Nebraska, Iowa, South Dakota and Montana. They also have operations in Mexico and Canada. Thus, climate can vary from semi-arid to more humid, and hot to cold; and each area may require a parasite program different from another.

Missy, whose father Pete Bonds was BEEF magazine’s 2011 National Stocker Award winner, helps map a parasite plan by region. “Some areas see few parasite problems; others require treatment 3-4 times/year,” she says.

Brown stomach worm

The brown stomach worm (Ostertagia) is a parasite that gets Bonds’ attention more than most. “It’s the most economically significant, and quite prevalent in Texas and much of the country,” says Jerry Woodruff, senior veterinarian for Boehringer Ingelheim Vetmedica, Inc. (BIVI).

Rich Linhart, Zoetis managing veterinarian of beef technical services, says it’s very important to identify parasites that effect your herd, but it’s also important to consider what stages of a parasite’s lifecycle a parasiticide is effective against. “How, and more importantly when, parasiticides are administered is critical in achieving the maximum benefit from a strategic deworming plan,” he says.

A Closer Look: Exactly When You Deworm Your Cows Matters

As an example, Linhart says it’s not wise to use a parasiticide that’s ineffective against a certain stage larvae at a time of year when those larvae are present or predominant. “A better choice is to select a product that’s effective in controlling many species and stages of parasites, and use that product at a time of year that returns the most benefit in terms of pounds of beef gained.

Ostertagia and Cooperia species both impact cattlemen’s bottom line. Failure to control the inhibited and uninhibited L4 larvae of Ostertagia can contribute to re-infection and failure to achieve the full economic benefit of a parasite control program. Most products will eliminate the adult forms of Ostertagia; the same cannot be said for control of the larval stages of the parasite,” Linhart adds.

Mike Mustian, a BIVI territory manager who works with Bonds, says the worse the brown stomach worm infestation is, the more that animal’s appetite is decreased. “It’s important to get cattle treated early before heavy forage growth,” he says.

Although some regions have faced drought, areas where even small amounts of rainfall or snow have occurred can see a quick rebound of grasses. “Even heavy dew can promote worm transmission,” Mustian says. “The worm only needs a droplet of water to get on that blade of grass. When cattle start grazing, parasites can start harming them internally.”