In the past two articles, we discussed controlling BVD. Farm biosecurity best management practices is an integral part of controlling not only BVD, but any disease that can enter your farm through foreign sources. Biosecurity is the cheapest and most effective method of disease control since vaccinations cannot eliminate disease and treatment can only reduce losses. Most cattle diseases are spread by cattle blood, saliva, manure, urine or exhaled air and special attention needs to be paid to reducing contact from animal to animal or animal to object to animal. This is best done by a combination of animal isolation, control of movement onto and around the farm, proper insect control, as well as and cleaning and disinfection.
Cattle disease is most frequently spread by contact between cattle and limiting this contact is the most important part of biosecurity. Newly arriving cattle should be isolated from other cattle for a minimum of 30 days. The isolation area should be separated from any other cattle housing areas and is best located where drainage and prevailing wind direction is away from the rest of the farm. Health records should be requested for all incoming animals and they should be watched closely each day for early signs of disease. Testing for common diseases, such as BVD, Anaplasmosis, and Johne’s disease, should be done early in the isolation period so the results will be available before the animal is put with other cattle on the farm. Deworming and vaccinating these animals are also worthwhile. Sick animals should also be isolated until all signs of disease are gone for at least one week. Weaned, younger cattle are best kept separated from older animals since they are still building immunity and are generally more susceptible to disease. Animals in isolation should be handled only after all other animals are handled for the day. Dead animals should be disposed of by rendering, burning, deep burial or composting so that they do not serve as a source of disease to live animals. If there is any question as to why the animal died, a necropsy (an animal autopsy) should be performed to determine the cause of death. This service is offered by Ellington Lab in Nashville as well as The University of Tennessee CVM.
Traffic onto the farm must be controlled for biosecurity to be effective. Disease can be spread by people, other domestic animals, rodents such as rats or mice, birds such as pigeons, insects such as flies and vehicles. The farm should be posted and gates should be locked when no one is around. A single entrance into the farm is easier to monitor and control than several entrances. Visitors to the farm should wear clean clothes and footwear that is free of manure. Plastic disposable boots should be available, if needed. Anyone handling animals should wash their hands before handling each animal and between animals, or wear disposable gloves. Vehicles that have been on other farms should not be allowed into barn lots or pastures. Pets from outside should be kept away from animals and feed sources. Feed and agricultural chemicals should be stored in a secure location. Finally, an effective program of pest control should be in place. This may include fences, screens traps or baits.
Cleaning and Disinfection
Disinfection means to render an object free of germs. Some common examples of objects that can spread disease are handling facilities such as chutes, balling guns, stomach tubes, dehorners, castration equipment and any other object that is used on more than one animal without proper disinfecting. It is best to dispose of disposable syringes and needles after they are used once. Non-disposable syringes and needles are best boiled, rinsed, dried and stored in plastic bags until their next use. Do not use disinfectant on needles and syringes as this will render vaccines useless. For disinfection to be effective, the object to be disinfected must be clean. A thorough scrubbing with soap and water followed by rinsing will remove most germs. The presence of manure or other body fluids such as saliva will make disinfectants ineffective. Several good disinfectants are available from animal’s health product suppliers and are very effective if used as directed. A good disinfectant that is commonly available is chlorohexidine, available as a 2% solution.
Disinfectants will work well if:
- The object to be disinfected is clean. Remove any manure, blood or saliva on the object to be disinfected.
- The disinfectant is designed to be effective against the germs to be killed. Always buy a disinfectant that is effective against a wide variety of common germs.
- The disinfectant is mixed properly. Too little or too much disinfectant in a solution will cause the disinfectant to work less well. Always follow label directions for mixing.
- The disinfectant is in contact with the object for at least 5 to 10 minutes.
Hypochloric acid (bleach) is a commonly used, inexpensive and effective disinfectant for which directions for use are not available on the label. Some points to remember about the use of bleach as a disinfectant include:
- Bleach can produce annoying or even toxic fumes and should always be used outside. Never mix bleach with ammonia or vinegar as a very toxic gas is produced.
- Bleach is often used in too concentrated a form and one eighth to one half cup per gallon of water is all that is needed.
- Bleach solution for disinfection cannot be stored and must be made fresh daily.
- Bleach is corrosive to metals, deteriorates fabrics, irritates skin and some individuals are very sensitive to bleach fumes.
An effective program of biosecurity, including isolation, control of movement into and around the farm and disinfection of items used on more than one animal is the cheapest and most effective form of disease control for the beef herd. Even small management changes directed towards disease control can yield a healthier beef herd. If you have any questions about designing a biosecurity program for your farm, please contact your local veterinarian, Extension agent, or Lew Strickland at firstname.lastname@example.org, or 865-974-3538.