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maintain a closed herd | calf management | vaccination | reducing stress | disinfectants, sanitation | controlling general access to the herd | separating animals into different groups

Introduction: Biosecurity by definition means to create an environment where infectious diseases are removed and prevented from spreading. A failure or "break" in biosecurity can result in disease, decreased production, death, and ultimately profit loss. In general, adequate biosecurity can be accomplished when two major categories are understood and then addressed. These categories, along with appropriate subcategories are listed below:

  1. Remove the source or potential host for the infectious disease by:
  1. Maintaining a closed herd or carefully monitoring new additions to the herd.
  2. Maintaining a superior calf management program.
  3. Developing a written and consistent herd vaccination, de-worming, and parasite control program. This can help prevent any outside source of infection from entering the herd.
  4. Controlling the amount of stress placed on each animal.
  5. Providing adequate nutrition and water for the various stages of production and growth.
  1. Prevent the spread of infectious disease by:
  1. Using proper disinfection, sanitation, and handling techniques with potentially infectious areas, equipment, or animals.
  2. Controlling the access that people, vehicles, rodents, and other animals have to the herd.
  3. Separating animals into different groups.
  4. Utilizing artificial insemination (A.I.) instead of natural service.

Each of the above areas are given additional detail in the following information and should be modified under the direction of the local veterinarian to fit each operation’s needs and goals.


Remove the Source of the Infectious Diseases

  1. Maintain a closed herd:
  1. To prevent new diseases from entering a herd, it is highly recommended to maintain a closed herd. A closed herd is one that does not receive any replacement animals from an outside source, and replacement heifers/bulls are raised.
  2. If it is not possible to maintain a closed herd, certain precautions are essential:
  1. Replacement heifers and bulls should be purchased before they reach sexual maturity.
  2. All new animals should be examined by a veterinarian for any signs of infectious disease. Tests should be run to ensure that the cow is free of Johnes disease, bovine leukosis (BLV), Mycoplasma, Staph. aureus, brucellosis, bovine viral diarrhea (BVD), and others.
  3. All new animals should be placed in an isolation pen for 3-4 weeks. During this time, the animal should be examined for signs of disease. This may involve taking the temperature, listening to the lungs, drawing blood samples for testing, and observing the general attitude of the animal. If no signs of disease have occurred after the 3-4 weeks of isolation, the cow can be placed with the other animals in the herd.
  4. Bulls over 4 years of age have the tendency to harbor trichomoniasis; therefore, older bulls should be culled. All bulls should be tested for trichomoniasis every year and all new bulls should have a breeding soundness evaluation (BSE) performed (see page A712).
  1. Newborn calves and calf management:
  1. All pregnant animals should be moved to a close-up dry pen or a maternity pen prior to calving. This pen should be designed for calving and should be used for only this purpose. It should be clean, dry, and have the necessary climate control elements to avoid temperature extremes. All animals should be removed from this area after calving.
  2. Depending on management issues, there are two ways of handling calves after birth. One method dictates that the calves should be immediately removed from the mother. This is important in situations where the mother has poor colostrum (a heifer) or has an infectious disease that can be shed in the milk (Johnes disease, BLV, BVD, etc.). Separation is also important when animals are born in a dirty environment where the mother’s teats have the potential to be contaminated with manure. These calves will require colostrum that is force fed. Another method of calf management requires that the calf be left with the mother long enough to receive colostrum from the mother. In these situations, cleanliness of the mother (udder, legs, tail) and surrounding environment are critical.
  3. All calves should receive 2 quarts of colostrum in the first 6 hours of life. For additional suggestions see page A122.
  4. Each calf should have the navel dipped immediately after birth. Povidone iodine (betadine) is recommended and can be administered in two ways: the entire umbilical cord and opening into the abdomen can be submerged in the iodine, or the iodine can be sprayed onto the cord and surrounding structures. Do not inject the iodine into the umbilical veinSee page B156 for instructions on dipping navels.
  5. Each calf should have its own hutch/pen/area. This topic is given more attention under "separating animals according to age."
  6. A vaccination program should be in place for the entire herd. For vaccination recommendations for calves, refer to page A905.
  1. Vaccination, de-worming, and parasite control programs:
  1. These programs should address the diseases and parasites that are commonly found in the area or on the farm.
  2. These programs should be developed under the direction of a local veterinarian and should be modified every 6 months.
  3. Each program should have specific protocols for each age and type of animal. The information should be written down and followed exactly. The programs should identify what products are used, how they are administered, and how often they are given.

* For additional information on handling vaccines, and developing a vaccination or de-worming program, refer to pages A900, A905, and A620 respectively.

  1. Reducing Stress - Stress comes in many different forms for a cow or calf. Stress in an animal can come from an internal source (sickness, poor nutrition, etc.) or an outside source (hot and cold extremes, overcrowding, etc.). Any stress will cause the cow’s internal disease defenses (immune system) to malfunction. This renders the cow more susceptible to disease and infection. Many of the internal causes of stress have been or will be addressed in other areas of this discussion. The following will identify the major causes of stress from an outside source and identify some recommendations.
  1. Avoid heat stress by:
  1. Providing adequate fresh, cool drinking water. An easy way of calculating the amount of water a milking cow will require is by taking the pounds of milk she produces per day and dividing that number in half. This number is the gallons of water the cow is likely to consume each day. For example, a cow that is producing 50 lbs. of milk per day will consume approximately 25 gallons of water.
  2. Providing plenty of shade. Placing shade over feed bunks and troughs will increase consumption during the hotter times of the day.
  3. Allowing adequate air circulation and ventilation.
  4. Avoiding over-crowding in holding and feeding areas.
  5. Using sprinkler systems. These systems should NOT be designed to soak the cow or create wet, muddy areas. The goal of sprinkling cows is to wet the surface of the skin and allow proper ventilation and air exchange to evaporate the water, taking heat away from the body.
  1. Avoid cold stress by:
  1. Maintaining optimal indoor winter temperatures around 45°F.
  2. Calves may require a higher temperature depending on protection and draft control.
  3. Providing sufficient wind breaks and shelter as the environment dictates.
  4. Some key areas to consider include insulation, ventilation, concentration of animals, and heating sources.
  1. Minimize stressful events by:
  1. Not performing several stressful procedures (moving pens, shipping, vaccinating, dehorning, hoof trimming, etc.) at the same time.
  2. Handling the animals in a calm and quiet manner. Excessive yelling, kicking, and prodding only compounds the amount of stress placed on the animal.
  1. Relieving stress in general by:
  1. Avoiding over-crowding.
  2. Allowing adequate space and time to move/exercise.
  1. Provide proper nutrition and plenty of clean, fresh water:
  1. A nutritionist familiar with the particular farm should be utilized for all nutrition decisions.
  2. The average water consumption can be calculated using the information found under "avoiding heat stress" on the previous pages.

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Prevent the Spread of Infectious Disease

  1. Disinfectants, sanitation, and proper handling techniques with potentially infectious areas, equipment, and animals:
  1. Some of the common disinfectants include chlorhexidine (Nolvasan), betadine (iodine), and bleach (Clorox). Each of these solutions should be diluted before use. Equipment such as calf pullers, chains, tube feeders, over boots, etc. should be soaked in one of these products for at least ten minutes before use. These products are generally effective against most bacteria and viruses.
  2. When using any piece of equipment on multiple animals, it should always be sanitized between each animal. This is particularly important when treating any animal with an infectious disease. Coveralls, boots, gloves, and all equipment should be cleaned immediately after use. The slightest contamination (manure, saliva, etc.) on any item can spread disease to another animal. For cleaning smaller equipment, chlorhexidine is the product most often recommended.
  3. When handling any animal with diarrhea (scours) or pneumonia, the use of latex gloves is highly recommended.
  4. All pens, hutches, stalls, lots, etc. should be kept clean, manure free, and as dry as possible. In dry lot situations, it is often helpful to disk or till the area on a regular basis. This exposes the bacteria and other organisms to the sun and speeds their destruction.
  1. Controlling general access to the herd - Vehicles, humans, rodents, and other animal species can bring many infectious diseases onto a farm.
  1. It is critical that access to the herd be limited to those people and vehicles that are essential. It is not uncommon to have a veterinarian or nutritionist wash their boots and even truck tires before they enter a premises.
  2. Rodent and bird populations should be kept under control.
  3. Dogs, deer, and other animal species should not be allowed to mingle with the herd.
  1. Separating animals into different groups - This is most commonly done during the growing stages.

Table #1: Calf housing requirements

Age of Calf (months)

Number of Calves per pen

Recommended square feet per animal













  1. In the 0-2 month age group, the calves should be separated in a way that any nose to nose contact with other calves is prohibited.
  2. All individual calf hutches/pens should be moved to new locations on a regular basis. This allows for adequate cleaning and exposes disease causing organisms to sunlight and disinfectants.
  3. A separate maternity pen should also be established. This pen should:
  • be manure free and well bedded with clean straw.
  • be warm in the winter and cool in the summer.
  • be dry and have plenty of ventilation.
  • contain a head catch for handling animals with problems.
  1. These maternity pens should only contain cows that are ready to calve. Once they have calved, the cows and calves should immediately be moved to the appropriate locations outside of the maternity pen area.
  2. Maintain a sick or treated cow milking string and milk this string last. This will reduce the spread of infection to other cows in the herd.
  1. Artificial insemination vs. natural service:
  1. A.I. breeding will help reduce the chance of spreading most diseases if proper insemination techniques are followed. If A.I. is not used, all bulls should be tested for trichomoniasis every year and all new bulls should have a breeding soundness exam (BSE) performed.
  1. Whenever large groups of animals and people are in one location, the chance of spreading disease increases dramatically. It is important to understand that people can spread infectious diseases from one animal to another through contaminated shoes, hands, brushes, halters, etc. The following are suggestions for organizers and those that participate in shows or fairs where large numbers of animals and people interact:
    1. Implement and practice effective biosecurity measures at the event site.
    2. Veterinary exams of all animals participating or being shown in the event should be required.
    3. All international travelers who have returned within the last 5 days should avoid animal exhibits and any other interaction with animals at the event.
    4. Discourage visitors (through the use of fencing, signs, and monitors) from touching or petting exhibited animals, except at designated petting areas.
    5. Prohibit the public from eating and drinking in animal exhibit areas.
    6. Prohibit and prevent the public from feeding human food to animals.
    7. Throughout the duration of the event, have a veterinarian routinely examine the animals for clinical signs of disease.
    8. Advise producers and owners to isolate their animals for a minimum of 5 days after the event. Have the owners review the recommendations on maintaining a closed flock/herd discussed above, and consult with their veterinarian on the proper ways of reintroducing the animals into established flocks/herds.

The following table lists some of the common disinfectants that can be used to kill most bacteria and viruses:

Product    Mixing Instructions    Final Dilutions
Follow label directions    Varies
Acetic acid
Add 4.6 ounces (138 mLs or 1/2 cup) of acetic acid to 1 gallon of water - then mix thoroughly    4%
Bleach    Add 3 ounces of bleach to 2 gallons of water - then mix thoroughly    3%
Follow label directions    1%

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More Dairy Info

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