Emerging Health Issues
Working group considers use of chlortetracycline under the new VFD rules, economic costs of a potential FMD outbreak and calfhood pneumonia.
Beef cattle producers, veterinarians and extension educators, as well as state and federal animal health officials, assembled for the National Cattlemen’s Beef Association (NCBA) Emerging Health and Research Issues Working Group, hosted during the 2017 Cattle Industry Convention in Nashville, Tenn. Three guest speakers led discussions regarding the recently implemented veterinary feed directive (VFD) requirement, the economic consequences of a foot-and-mouth disease (FMD) outbreak and the incidence of pneumonia among preweaned calves.
Chlortetracycline and the VFD
Veterinarian Mike Apley, a professor at the Kansas State University (K-State) College of Veterinary Medicine, noted that despite efforts to educate producers and feed distributors over many months prior to the implementation of the federal VFD rule on Jan. 1, 2017, veterinarians still receive many questions about VFD requirements. Apley said he had fielded 10 to 12 questions per day during the first month following implementation.
Apley reminded his audience that a VFD is now required for administration through livestock feed of “medically important” antibiotics — those antibiotics of a type also used to treat disease in humans. Among them are tetracyclines. Many producer questions are related to use of chlortetracycline (CTC).
“Over time, there has been increased use of CTC to treat food animals. That’s the likely driver of the VFD rule,” stated Apley.
Apley noted that administration of CTC through salt and mineral supplements had become a go-to remedy for pinkeye and foot rot in cattle. He explained that veterinarians cannot write a VFD for CTC use in treating either ailment. Treatment of pinkeye and foot rot constitute extra-label uses of CTC, which is prohibited under the new rule.
Preparing for an FMD outbreak
Treatment of pinkeye and foot rot constitute extra-label uses of CTC, which is prohibited under the new VFD rule.Discussing the potential economic impact of an outbreak of FMD was K-State agricultural economist Dustin Pendell. He noted that the last outbreak in the United States was in 1929 and, despite safeguards against introduction from a foreign source, producers and animal health officials should not become overconfident and discount the potential for reemergence.
“FMD is not a public health hazard and [an] outbreak’s impact to consumer demand (for meat and animal products) should be relatively small and short-lived,” said Pendell. “However, the economic loss to agriculture has been estimated at from $16 to $140 billion, with producers bearing most of the burden.”
Pendell and his colleagues have been examining the feasibility of an FMD response plan implemented on a regional basis, relative to where an outbreak occurs, the kind of operation where FMD is detected, and the potential for infection to spread to other operations within a certain radius of the first site of infection.
Calfhood pneumonia
Working group members also heard from Mississippi State University research veterinarian Amelia Woolums, who talked about the incidence of pneumonia among nursing calves. She cited 20 years of data from the U.S. Meat Animal Research Center (USMARC) at Clay Center, Neb., suggesting that pneumonia may affect 4% to 23% of calves in any given year, or an average of 11% annually.
In many affected calves, suggested Woolums, pneumonia is likely the result of failed passive transfer of immunity from the dam. Infection may also be introduced through the introduction of calves from outside the herd that are grafted onto cows having lost their own calves. Older weaned calves introduced to an operation may also introduce the infection.
Woolums said management practices that may enhance opportunity for infection to spread include any that bring calves into close contact, even temporarily, and particularly if accompanied by stress. Such practices could include creep-feeding, handling of pairs in association with estrus synchronization and artificial insemination, transportation to other sites, or intensive grazing systems.
“I’m not saying these practices should not be used; they can be extremely valuable,” stated Woolums, “but if pneumonia in preweaned calves is a problem, we need to think about how we might adapt management to mediate the problem. In some cases, the value of certain practices — creep-feeding for example — may need to be reconsidered.”
Editor’s Note: Troy Smith is a freelance writer and cattleman from Sargent, Neb. This article was written as part of Angus Media’s coverage of the 2017 Cattle Industry Convention.