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:
- Maintaining a closed herd or carefully monitoring new additions to the herd.
- Maintaining a superior calf management program.
- 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.
- Controlling the amount of stress placed on each animal.
- Providing adequate nutrition and water for the various stages of production and growth.
- Using proper disinfection, sanitation, and handling techniques with potentially infectious areas, equipment, or animals.
- Controlling the access that people, vehicles, rodents, and other animals have to the herd.
- Separating animals into different groups.
- 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
- 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.
- If it is not possible to maintain a closed herd, certain precautions are essential:
- Replacement heifers and bulls should be purchased before they reach sexual maturity.
- 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.
- 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.
- 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.
- All calves should receive 2 quarts of colostrum in the first 6 hours of life. For additional suggestions see page A122.
- 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 vein. See page B156 for instructions on dipping navels.
- Each calf should have its own hutch/pen/area. This topic is given more attention under "separating animals according to age."
- A vaccination program should be in place for the entire herd. For vaccination recommendations for calves, refer to page A905.
- These programs should address the diseases and parasites that are commonly found in the area or on the farm.
- These programs should be developed under the direction of a local veterinarian and should be modified every 6 months.
- 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.
- Avoid heat stress by:
- 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.
- Providing plenty of shade. Placing shade over feed bunks and troughs will increase consumption during the hotter times of the day.
- Allowing adequate air circulation and ventilation.
- Avoiding over-crowding in holding and feeding areas.
- 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.
- Avoid cold stress by:
- Maintaining optimal indoor winter temperatures around 45°F.
- Calves may require a higher temperature depending on protection and draft control.
- Providing sufficient wind breaks and shelter as the environment dictates.
- Not performing several stressful procedures (moving pens, shipping, vaccinating, dehorning, hoof trimming, etc.) at the same time.
- Handling the animals in a calm and quiet manner. Excessive yelling, kicking, and prodding only compounds the amount of stress placed on the animal.
- Avoiding over-crowding.
- Allowing adequate space and time to move/exercise.
Prevent the Spread of Infectious Disease
- A nutritionist familiar with the particular farm should be utilized for all nutrition decisions.
- The average water consumption can be calculated using the information found under "avoiding heat stress" on the previous pages.
- 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.
- 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.
- When handling any animal with diarrhea (scours) or pneumonia, the use of latex gloves is highly recommended.
- 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.
- 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.
Table #1: Calf housing requirements
Age of Calf (months) |
Number of Calves per pen |
Recommended square feet per animal |
0-2 |
1 |
24 |
2-4 |
3-5 |
30 |
4-6 |
6-12 |
30 |
6-18 |
10-20 |
30 |
- 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.
- 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.
The following table lists some of the common disinfectants that can be used to kill most bacteria and viruses:
Product | Mixing Instructions | Final Dilutions |
Chlorhexidine (Nolvasan) |
Follow label directions | Varies |
Acetic acid (vinegar) |
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% |
Virkon-S (Antec) |
Follow label directions | 1% |