Biosecurity Issues for Virginia Cattle Operations: Preventing a Disease Outbreak
Livestock Update, March 2002
W. Dee Whittier, D.V.M., MS., Prof., VA-MD Regional College of Veterinary Medicine
All successful cattle producers must have keeping their cattle healthy as a major objective. There are a number of approaches to accomplishing this goal. Vaccination programs, keeping resistance high through good nutrition, early detection and treatment of disease and a number of other management techniques are keys to keeping cattle healthy. One very important area of management that is key to disease prevention is biosecurity. The goal of biosecurity is to stop transmission of disease-causing agents by preventing, minimizing or controlling cross-contamination of body fluids (feces, urine, saliva, etc.) between animals, animals to feed and animals to equipment that may directly or indirectly contact animals. Biosecurity management practices are designed to prevent the spread of disease by minimizing the movement of biologic organisms and their vectors (viruses, bacteria, rodents, flies, etc.) onto and within your operation.
When animals develop infectious diseases, the source of the infectious agent (virus, bacteria, parasite, etc.) is often unknown. Typical sources for the agents include:
Biosescurity measure can be completely effective in preventing disease from some of these sources, somewhat effective with others, and completely ineffective with still others. Biosecurity can be very difficult to maintain because the interrelationships between management, biologic organisms and biosecurity are very complex. While developing and maintaining biosecurity is difficult, it can be the cheapest, most effective means of disease control available, and no disease prevention program will work without some biosecurity measures.
Of all the possible breakdowns in biosecurity, the introduction of new cattle and traffic pose the greatest risks to cattle health. Properly managing these two factors should be a top priority in your operation. Biosecurity plans should be developed to meet the specific needs of each operation.
Biosecurity has three major components:
When effectively managed these components meet the principle biosecurity objective of preventing or minimizing cross-contamination of body fluids (feces, urine, saliva, respiratory secretions, etc.) between animals, animals to feed and animals to equipment.
Isolation prevents contact between animals within a controlled environment. The most important step in disease control is to minimize commingling and movement of cattle. This includes all new purchases as well as commingling between established groups of cattle. Even in operations that have high cattle turnover, such as feedlots, keeping feeding groups from mixing is an important biosecurity measure. Isolate feedlot hospital cattle and return them to their home pen as soon as possible. Long-acting therapies have improved our ability to minimize movement of infectious organisms between groups. An important biosecurity action on farms is to separate cattle by age and/or production groups. Facilities should be cleaned and disinfected appropriately between groups. Visit with your veterinarian about specific isolation management procedures and how they can be applied to control targeted diseases.
Traffic control includes traffic onto your operation and traffic patterns within your operation. It is important to understand traffic includes more than vehicles. All animals and people must be considered. Animals other than cattle include dogs, cats, horses, wildlife, rodents and birds. The degree of control will be dictated by the biology and ecology of the infectious organism being addressed, and the control must be equally applied. Stopping a truck hauling cattle from driving onto your operation as a biosecurity measure for controlling BVD may not be beneficial since the virus is spread from animal to animal. Buying cattle from herds that have a verifiable quality vaccination program would be more important in maximizing biosecurity. However, it would be important for the truck to have been adequately cleaned before hauling the cattle. Traffic control can be built into the facilities design. An example would be placing cattle loading facilities on the perimeter of the operation.
If possible, separate equipment should be used for handling feedstuffs and manure. Vehicles and employees should not travel from the dead cattle area without cleaning and disinfecting. The dead animal removal area should be placed in a location that allows rendering trucks access without cross-contaminating healthy cattle. Vehicle cleaning areas are becoming more common in commercial feedlots. Unfortunately they are frequently used only for trucks and heavy equipment. Management should consider extending a decontamination policy to other vehicles (especially tires) that are used across biosecurity control areas on the operation. Ask your biosecurity resource team to help you evaluate traffic control on your operation.
Sanitation addresses the disinfection of materials, people and equipment entering the operation and the cleanliness of the people and equipment on the operation. The main objective of sanitation is to prevent fecal contaminates from entering the oral cavity of cattle (fecal - oral cross contamination). Equipment used which may contact cattle's oral cavity or cattle feed should be a special target. The first step in sanitation is to remove organic matter, especially feces. Blood, saliva, and urine from sick or dead cattle should also be targeted. All equipment that handles feed or is introduced into the mouth of cattle should be cleaned, including disinfection as appropriate, before use.
Loaders used for manure or dead cattle handling must be cleaned thoroughly before using for feedstuff. It would be best to use different equipment. Minimize the use of oral equipment and instruments such as balling guns, drench equipment and tubes. If used at processing and treatment, thoroughly clean and disinfect between animals. Store cleaned equipment in clean, dry areas. Avoid storage in tanks or containers containing disinfectants because most disinfectants are neutralized by organic material. Disease transmission is commonly traced to the use of those storage tanks.
All beef cattle producers should develop a biosecurity plan and commit to its implementation. Committing to a biosecurity plan is a vital step toward controlling of infectious disease. Keeping pathogens out of a herd improves production efficiency, lowers costs and reduces risks to employees and family.