Column by Russ Daly, Professor, SDSU Extension Veterinarian, State Public Health Veterinarian
Imagine 10 percent of the nation's beef and dairy cattle herd infected with a contagious disease causing pregnancy loss and reproductive failure.
What's more, that same contagious disease makes people sick, sometimes with long-term repercussions.
This was the situation in the mid-1930's with brucellosis, a bacterial reproductive disease of cattle.
Implicated for decades as a significant animal and public health problem, in 1934 the U.S. Department of Agriculture (USDA), in conjunction with state officials, embarked on a brucellosis eradication program, remnants of which continue today.
Early eradication efforts consisted of blood testing and slaughtering infected animals.
While this helped rid herds of a source of infection, it did not prevent those infected cows from spreading the bacteria before they were detected.
That all changed in the early 1940s with the development of a brucellosis vaccine, sometimes called the "Bangs vaccine," for cattle.
Named the "Strain 19" vaccine, it quickly proved to be effective. Even if it did not prevent 100 percent of infections, it greatly reduced abortions and therefore disease spread.
In the mid-1990s, Strain 19 was replaced as the approved vaccine by "RB51," which offers similar protection but fewer problems with blood test interference.
It took time, but the U.S. brucellosis eradication program can now be considered a success.
Cattle brucellosis has been eradicated across the country, except for areas surrounding Yellowstone National Park, where wildlife remains a reservoir. As a result, many states have dropped requirements for brucellosis vaccination of heifers for their resident cattle and for animals entering from other states.
If most brucellosis vaccination requirements are no longer in effect, why should cattle producers continue to make the effort?
1. Bangs vaccination time is a good time for other heifer management practices as well.
Rules restrict brucellosis vaccination to heifers between the ages of 4 and 12 months of age.
During this time, heifers identified as replacements can also be given their first dose of pre-breeding reproductive vaccine, palpated for reproductive score, pelvic measured, retagged and have their udders examined.
In addition, since brucellosis vaccine must be administered by an accredited veterinarian, it gives the operation a built-in opportunity to utilize veterinary expertise to help select and prepare replacement heifers.
2. Bangs vaccination automatically gives heifers a USDA official identification. Vaccinated heifers receive an official tattoo designating the year of vaccination as well as a metal - or possibly RFID (Radio-frequency identification) official identification tag.
Even though brucellosis vaccination is not required to cross most state lines anymore, official identification is.
3. Bangs vaccination makes state officials' jobs easier. Brucellosis-vaccinated heifers have their official identification recorded and sent to the state veterinarian's office for storage.
Those records and identifications can become invaluable in investigations of disease outbreaks such as tuberculosis.
Having identification such as the Bang's tag number might mean the difference between an operation being declared "all clear" and having to test their animals when it comes to these disease tracebacks.
4. Bangs vaccination still holds value for many heifer purchasers. At the very least, it indicates that the heifers have at least had a chance to be examined and managed more closely than those not vaccinated against brucellosis.
5. Brucellosis hasn't been eradicated from the face of the earth. Yes, the chance of a dairy or beef cow in a South Dakota herd encountering brucellosis is low. But, as long as a source of the disease exists in the greater Yellowstone area - and other countries - protection is not a bad idea.
If the day ever comes when brucellosis vaccination is a rarity, we could have a cattle population once again quite susceptible to that important disease.
For beef and dairy producers, the best source of information on how brucellosis vaccination fits into an operation is their local veterinarian.
In South Dakota, the Animal Industry Board has a great deal of useful information on brucellosis. To learn more, visit aib.sd.gov