Bruce Schultz | 5/10/2006 1:56:09 AM
ROSEPINE – A veterinarian told cattle producers at the recent LSU AgCenter Rosepine Research Station Field Day that they should be on the lookout for bovine viral diarrhea virus (BVD) because it suppresses immunity to other diseases and can cause pneumonia and abortions.
That was one of the reports during the May 4 field day that was designed to provide area cattle producers with the latest information on cattle and forage production.
In that report on BVD, Dr. Christine Navarre, LSU AgCenter state extension veterinarian, said stillbirths and fertility problems are also caused by the virus.
The disease is highly contagious, but vaccines are available, Navarre said, adding that spot testing of the herd should be conducted to see if the disease is present before testing all individual animals.
Pregnant cows can carry an infected fetus, and tests won’t pick these infections up, she said, and buying pregnant females opens a pathway for exposing a herd.
"That is one of the most common ways BVD gets into a herd," she said.
If a pregnant cow in the first half of gestation gets exposed to BVD, the fetus gets infected, Navarre explained.
Animals are exposed to the disease upon birth of a calf. An early fetus’ immune system doesn’t fight BVD because it doesn’t recognize the disease as an infection, she said.
"Once these infected calves are born, they can look perfectly normal but can shed the disease, exposing the rest of the herd" she said.
In other precautions about ways the disease could enter a herd, Navarre said cattle that are show animals should be isolated from the rest of a herd for 30 days after being brought home.
She also cautioned that cattle mixed with other herds in the evacuation following Hurricane Rita also are at increased risk.
Vaccines won’t eliminate the problem, but they will reduce the problem, she said. Vaccines for cows labeled for fetal protection are available but are not 100 percent effective, either.
"Vaccines only work in healthy animals," she said.
Navarre urged producers to use a fresh needle for every animal to reduce chances of spreading diseases when injecting vaccines.
"It’s cheap insurance," she said. "It’s not that expensive."
Turning to another disease, Navarre said some states are dropping requirements for brucellosis vaccines, but she recommended producers continue the safeguard, which is still required in Louisiana.
"It just leaves your options open," she said.
As for other disease precautions, the LSU AgCenter veterinarian also said calves become susceptible to Blackleg disease as soon as they start grazing. And she said while anthrax has not been reported recently in Louisiana, it has been found in Texas. Navarre said she doesn’t recommend routinely vaccinating for anthrax unless the disease has occurred on a farm previously.
In other reports during the field day, cattle producers also heard from Dr. David Sanson, resident scientist at the Rosepine station, about a research program of feed supplements in a heifer development project. They also heard talks on forage research, ryegrass grazing, pasture weed control and hornfly control.
Dr. David Boethel, LSU AgCenter vice chancellor for research, said many cattle farmers in South Louisiana were affected by last year’s hurricanes.
"I certainly think our cattle research programs will add to their knowledge and help them get back on their feet," Boethel said.
Writer: Bruce Schultz at (337) 788-8821 or firstname.lastname@example.org