News Update
August 7, 2009

Controlling BVD Fetal Infection

When designing a bovine viral diarrhea (BVD) control plan, vaccination for prevention of birth of persistently infected (PI) calves should be a primary target. As the principal source of fetal infection from BVD, PI calves compromise herd health and profitability, as they place the entire herd at risk.

“PIs often serve as the source of BVD virus in the herd that can result in fetal infections the next year,” said Dale Grotelueschen, Pfizer Animal Health veterinarian. “Targeting the prevention of PI calves allows producers to lessen herd risk of BVD fetal infection, including the development of more PI calves the following year.”

Understanding how BVD can be spread in a herd through PI calves is an important step in developing a solid control plan. Depending on the stage of gestation, the effects of fetal infection from BVD can range anywhere from infertility to compromised immune systems to persistent infection.

Although not all PI calves survive past 6 to 12 months of age, those that do often appear healthy and reach maturity. These PI individuals typically shed the BVD virus heavily throughout their lifetime, making it difficult for dams, unborn calves and herdmates to escape infection.

Once the role of PI calves is understood, producers should evaluate their BVD control plan for its long-term efficacy and ability to break the PI cycle.

“Producers who plan their health programs over a multiyear window can do a better job of preventing PIs by designing approaches that reduce risk for exposure and minimize chances for occurrence of fetal infection,” explained Grotelueschen.

Finally, to ensure a BVD control plan adequately protects a herd from PI animals, it’s important to choose a vaccine that provides the highest possible label claim for PI protection. Because fetal infection can occur at any time during gestation, a vaccine with yearlong protection is also essential. Certain vaccines have been shown to provide duration of immunity for at least 365 days and prevention of BVD Types 1 and 2 PI calves. Vaccines like this provide producers with a convenient and flexible management system that requires less handling of cattle while increasing profit potential.

To explore the available options, work with your veterinarian to evaluate your vaccine’s label claim and duration of immunity. For additional information on Pfizer Animal Health’s portfolio of animal products, visit www.PfizerAH.com.

— Release provided by Pfizer Animal Health.

Vaccination With Parasite Control is a Must for a Healthy Herd

Even if producers do everything else by the book for vaccination, if they don’t control parasites and monitor nutrition, they may be throwing that investment away.

“I get a lot of herd health calls from producers asking what to vaccinate for,” says Christine Navarre, Louisiana State University (LSU) Extension veterinarian. “I won’t even talk about vaccination until we’ve addressed parasite control and nutrition. Without managing those two issues, they may not get all they can out of a vaccination program.”

Navarre is not alone in her concern. Parasites are listed by the University of California-Davis School of Veterinary Medicine as one of the common causes of vaccine failure.

“Studies have shown that parasite loads can reduce an animal’s ability to produce a strong humoral and cell-mediated immune response to antigens, such as vaccines,” says Frank Hurtig, director, Merial Veterinary Services. “A healthy immune response is necessary for vaccines to be effective. Parasites can hinder that process.”

Some of this reduced immune function may be attributed to parasites causing increased stress and malnutrition.

“Cattle need to be in good condition to get the best possible response to vaccination,” Navarre says. “Parasites disrupt stomach function, making it more difficult for cattle to absorb nutrients, which acts like poor nutrition. That means cattle may not have the nutrients available to mount an immune response to vaccination.”

Fall vaccination and preconditioning programs are designed to help calves prepare for the challenges of weaning and shipping. Hurtig says it is essential that producers also control parasites with a product they can trust, such as an Ivomec® (ivermectin) brand product, as part of their fall protocols to help calves mount a proper immune response to vaccines.

“Producers should follow a preconditioning program like the veterinarian-certified Merial SureHealth® Calf Preconditioning Program that includes controlling parasites with an Ivomec brand product,” Hurtig says. “Parasite control and vaccines both help give calves a strong start in a feeder or heifer development program. And since Ivomec Brand Products are backed by a 100% Product Satisfaction Guarantee from Merial, producers’ parasite control investment is protected as well.”

Just as feeder calves need to be treated for parasites, Hurtig says producers also need to include parasite control as part of fall cow and replacement heifer health protocols.

“Fall cow vaccinations serve double duty, protecting the cow and providing immunity to the calf at birth via colostrum,” Hurtig says. “These vaccines can head off a lot of trouble and expense for producers, but should be used in conjunction with parasite control to help clear the path for maximum effectiveness.”

He says a fall parasite control treatment will help ensure the vaccination program is as successful as possible and will help reduce pasture parasite loads and clear cattle of parasites before winter.

To achieve these benefits, Navarre says timing is key. She encourages producers to rethink what herd health practice determines when they work cattle.

“The timing of parasite control is so important that I try to time vaccinations to when parasite control is necessary, not the other way around,” Navarre says. “I want to know that timing for parasite control is right because it is more critical than timing for vaccination in many herds.”

When choosing a parasite control product this fall, Hurtig notes that producers should consult with a veterinarian for the optimal parasite control practices in their area, read labels carefully and choose a product that will control all of the parasites of concern for their individual herd. It’s equally critical, he adds, for producers to protect their parasite control investment by using a product that is backed by a trusted manufacturer.

For more information, producers should contact their veterinarian or local Merial territory manager, visit www.IVOMEC.com or call 1-888-MERIAL-1.

— Release provided by Merial.

University of Idaho Extension Offers Lost Rivers Grazing Academy Sept. 15-18

University of Idaho Extension will once again offer its internationally recognized and national award-winning Lost Rivers Grazing Academy on Sept. 15-18 at the Eagle Valley Ranch near Salmon. Ranch staff members all Grazing Academy alumni are successfully applying management-intensive grazing principles on the 600-cow ranch along Bohannan Creek.

The four-day workshop will help participants improve their forage production and quality, increase their stocking rates and animal performance, and boost their net income, said Chad Cheyney, University of Idaho Extension educator in Butte County. It will feature a combination of classroom and field exercises to help operators understand the principles of management-intensive grazing of irrigated pastures and give them some solid practice. Working in small teams with 20 cow-calf pairs, they will learn how to let their livestock harvest the sun’s energy while using less fossil fuel and reducing their costs.

“It’s one thing to read about it, and it’s another thing to see it working on the ground,” Cheyney said.

About 230 livestock and pasture operators and 55 public agency personnel from 12 states, Canada, Mexico and Venezuela have attended the Lost Rivers Grazing Academy since 1998, he said. “Virtually all” have reported improvements in their operations that have more than paid for the cost of the program. “Some have participated more than once because every year and every season are different, and they learn new things, from us and from each other, every time they attend,” Cheyney said.

The Lost Rivers Grazing Academy will be taught by University of Idaho Extension faculty and by management-intensive grazing expert Jim Gerrish, formerly of the University of Missouri Forage Systems Research Center and now an internationally respected private consultant residing in Idaho. Mike Kossler and Jerry Elzinga of Eagle Valley Ranch will also make presentations.

Cost of the program, including all meals and materials is $450, with discounts for returning alumni and multiple parties from the same ranch. For more details, contact Cheyney at 208-527-8587 or ccheyney@uidaho.edu in Arco or University of Idaho Extension educator Scott Jensen at 208-896-4104 or scottj@uidaho.edu in Marsing. A brochure and registration materials are available at http://extension.ag.uidaho.edu/owyhee/AgLostRiversGrazingAcademy.htm.

— Release provided by University of Idaho Extension.

— Compiled by Mathew Elliott, assistant editor, Angus Productions Inc.