WSU Regional Livestock and Dairy Extension Specialist
While developing a national biosecurity curriculum for youth, four veterinarians (one each from VT, WI, MT, and WA, including yours truly) recently engaged in a prolonged discussion of a biosecurity article written by another veterinarian. The article compared the costs of various poultry farm biosecurity practices by relative effectiveness. Our discussion focused on this foundation, but we added factors relevant to livestock premises. Now, without the hours of discussion that preceded it (you are welcome!), is our list of the most cost-effective biosecurity practices for livestock farms.
Keep a Closed Herd
Herd additions pose the greatest threat of disease introduction to a farm. If possible, grow your own herd replacements, use artificial insemination, and do not take livestock to and from shows and sales. A closed herd reduces biosecurity risks tremendously.
You could allow no visitors whatsoever, or you could restrict their access to various parts of your farm. For example, visitors could see livestock in pastures from afar. There is no need for most visitors to go into barns, walk through feeding areas, touch animals, etc. Visitors who have contact with the same livestock species as you are of special concern; they should wear clean clothing and disinfected footwear if they visit your farm (Photo 1).
Photo 1. With visitors like this, biosecurity risks are elevated.
Photo credit: Dr. Jeanne Rankin.
Make Cleaning and Disinfection Easy
Establish and maintain handwashing sites and areas where it is easy to clean and disinfect boots, equipment, feed tubs, etc. Top-of-the-line facilities also have vehicle washing areas and shower-in/shower-out capability. Do not rely on footbaths—they are usually poorly maintained and spread infectious agents instead of control them. They do not provide the contact time needed to kill germs and are completely ineffective on dirty boots. Instead, clean footwear with soap and water first, then apply an effective disinfectant for the required contact time to kill pathogens. Discuss with your veterinarian what disinfectant to use.
Protect Feed and Water from Contamination
Any pathogens getting into animals’ feed or water have easy entry into their next host. Investigate designs for feed, water, and mineral access that prevent contamination with livestock manure, exclude vermin, and keep contents as clean as possible. Discourage cats from defecating in hay or grain by maintaining a litter box in the barn. Use exclusion netting or other devices to dissuade birds from roosting in barn rafters. Do not let animals drink directly from surface water that could contain pathogens or contaminants from upstream. Keep stored grains dry and store in rodent-proof containers.
Do Not Borrow Anything
Sharing equipment and tools with other livestock owners increases the risk of bringing a pathogen onto your farm. Borrowing equipment is a good way to import foot rot, sore mouth, ringworm, caseous lymphadenitis, winter dysentery, porcine epidemic diarrhea, and many other problems. This also goes for sharing bulls or other breeding males—they can introduce many more things than just new genetics.
Establish Quarantine and Isolation Areas
Every farm needs an area where sick animals can be isolated and treated, reducing disease spread throughout the herd. If you have decided to have an open herd, you will also need a quarantine area for herd additions and animals returning from shows, breeding, etc. Quarantine areas should be downwind from the herd; animals should remain there for at least 30 days and be checked daily for signs of contagious disease. Do herd chores first, then care for the animals in the quarantine area—better yet, assign one person to care for just the quarantined animals.
Rodents, birds, flies, other insects, etc. can passively spread some diseases and are required for the transmission of other diseases (Photo 2). For example, flies can spread pinkeye, E. coli and Salmonella on their feet or in their feces. Controlling vermin keeps feed, water, and farm premises cleaner; reduces damage to facilities; and reduces disease spread.
Get Two of Everything
Have barn and non-barn footwear; barn and non-barn clothing; equipment for healthy animals and sick animals; and tools for feed and separate tools for manure handling. Having specific clothing, footwear, and tools designated for certain uses will reduce the risk of moving pathogens around.
Cull (kill or sell at auction) any sick animals that do not respond to treatment or are chronic poor doers. Also cull animals that test positive for diseases but show no signs of illness; asymptomatic carriers are one of the most common sources of disease exposure for herdmates. One example: individual cattle persistently infected with the bovine viral diarrhea virus (BVD-PI) may appear healthy, but they are a reservoir for this serious pathogen that can cause pneumonia, abortions, diarrhea, fetal malformations, and reproductive dysfunction. Every cattle producer should know the BVD status of his/her herd, starting with testing for BVD-PI animals and immediately culling any positives.
Maintain a Line of Separation
Use gates, fences, and signs to keep things where they belong. Traffic such as delivery trucks should be controlled and routed through specific areas of a farm to reduce disease transmission risk. Likewise, parking areas should be situated to reduce the risk from vehicle tires and foot traffic. Keep gates locked to prevent unnecessary access and increased risk. Fences help prevent nose-to-nose contact between neighboring animals and among various groups of animals, such as youngstock and adults.
Do Not Purchase Diseases
If you purchase herd additions, know the disease status of the herd of origin and the individuals you intend to purchase. Discuss with your veterinarian which diseases are of concern and what tests should be done before you import new animals to your herd. NEVER purchase herd additions from livestock auctions or sale yards—you won’t know their history, disease status, or reason they are being sold. Don’t buy someone else’s problems!
Remember the Basics
Ensuring good air quality through effective barn ventilation, removing manure and dirty bedding promptly, and vaccinating against diseases of concern are good animal husbandry practices that will reduce disease risks. Perform daily chores from lowest to highest risk animals, such as healthy young, healthy older, quarantined, then hospitalized, washing hands and changing clothing in between as needed.
Preventing animal disease saves so many things—time, labor, money, worry, product loss, medication costs, veterinary expenses… and of course, animal illness and suffering. There are many more biosecurity steps possible in addition to those recommended here, but these practical and often low-cost suggestions should reduce the risk of disease introduction and spread significantly. An excellent web site with more disease control information is http://www.cfsph.iastate.edu/Infection_Control/index.php.