More on the Age of Ranch Biosecurity
By Lisa Duffey, Montana Beef Network Coordinator with Clint Peck, Senior editor, BEEF Magazine.
We’ve all grown up with the common sense adage that good fences make good neighbors. That’s probably as good an approach to ranch biosecurity, literally and figuratively as we can suggest. Good fences are the best way to keep out unwanted "visitors."
Go into town, and there’s hardly a business enterprise today that doesn’t have some type of intrusion deterring system. Certainly, locked doors are a fact of life. You might also find security fencing, surveillance cameras and even regular patrols included in a business’ security plan. But, few ranching operations have gone beyond the "good fences" concept − and put barriers in place to keep out organisms smaller then the wife’s cousin’s toy poodle.
But, some ranchers and cattle feeders are beginning to take the concept of "fences" to a new level. They are thinking more in terms of forming a (bio) security shield around their operations. "Biosecurity and security are different production issues, but both are important and must be properly addressed to protect the health of livestock in an operation," says Dr. Dee Griffin of the University of Nebraska-Lincoln Great Plains Veterinary Educational Center.
"The introduction of disease−causing organisms into a livestock operation can either be intentionally, as would be the situation in bioterrorism," Dr. Griffin says. "Or, it can be unintentionally introduced, as is often the case with improper biosecurity application procedures." The biosecurity and security needs of each production location should be reevaluated on a regularly scheduled basis.
"Biosecurity management and practices are designed to prevent the spread of disease by minimizing the movement of biologic organisms (viruses, bacteria, rodents, etc.) onto and within an operation. "Biosecurity can be very difficult to maintain because the interrelationships between management, biologic organisms and biosecurity are very complex," Dr. Griffin adds.
"While developing and maintaining biosecurity is difficult, it is the cheapest, most effective means of disease control available and no disease prevention program will work without it."
The BVD Virus Example
The bovine viral diarrhea (BVD) virus is a major viral disease impacting beef cattle reproduction and performance. The key source of BVD virus infection is the persistently infected (PI) animal. PI’s are the result of fetal exposure to the virus prior to the development of its immune system. BVD not only lessens reproductive performance but also produces disease in cattle including diarrhea, respiratory insult, mucosal ulcers and death.
Increasingly, veterinarians and cattle feeders are finding that the BVD virus suppresses the immune system, making the animal more susceptible to infection by other viruses and bacteria. There has been only limited work done on associating an economic cost with herds infected with BVD. But, feedlot studies suggest the cost $7.60/cwt. or approximately $30/animal that is expected to gain 400 lbs. during the feeding period. PI calves are very efficient at spreading the BVD virus to other animals. Current initiatives to develop effective BVD control programs are underway by the American Association of Bovine Practitioners, the Academy of Veterinary Consultants and state livestock associations.
The Colorado "PI−Free" Program
The Colorado State University Veterinary Diagnostic Laboratory and Colorado Department of Agriculture have been working with Colorado ranchers and cattle feeders to bring this disease under control. Two years ago, Colorado initiated a multilevel program hinging on removal of the PI animal to eliminate the most important source of exposure, effective vaccination programs and herd level biosecurity. This voluntary program is garnering significant attention around the cattle feeding community as a vehicle providing a source of "certified BVD PI−free" calves.
The architect of Colorado’s BVD Control Program is Dr. Jim Kennedy, director of the Veterinary Diagnostic Lab, College of Veterinary Medicine and Biomedical Sciences, at Rocky Ford, Colo. He says that when implementing a BVD control program some assumptions have to be made.
- First: The assumption that BVD is economically important to the cattle industry in a state or region. With the variability of market conditions and the predicted downturn in cattle prices, the need to return every dollar back to an operation during lean times is equally important as during robust market conditions.
- Second: The assumption that the PI animal is the primary source of BVD infection. The current hypothesis of BVD researchers is that without the PI there would be no BVD virus present. If we accept this hypothesis then a test and slaughter process would eliminate BVD virus infections from our cowherds.
- Third: The assumption that we can design a biosecurity program that can protect the cowherd from infection. A BVD biosecurity program should include quarantining and testing new entries, minimizing contact with other animals including the neighbors’ and wildlife, effective vaccinations and monitoring and evaluating our herd for the success of the program.
- Fourth: The assumption we can test effectively in a timely and affordable manner forBVD and most importantly BVD PI’s. Because of the low prevalence figures ( only 1 percent of all cattle in the U.S. and 4 percent of all herds contain PI’s), large numbers of cattle are tested without identifying any PI’s.
Montana Agroterrorism Briefing
When compared to other states, Montana has been identified as being uniquely vulnerable to acts of agroterrorism due to:
- The length and porosity of the sparsely−populated Montana/Canada border.
- Significant portions of Montana’s agricultural output are exported.
- Few firewalls are in place in to detect or contain an agroterrorism event.
Be alert to the possibility of agroterrorism, but don’t panic. This was the bottom−line message repeated often at a national conference recently held on agroterrorism.