General Farm Biosecurity Practices

Bacteria, viruses, or other microscopic organisms (microbes) are called infectious when they are capable of causing disease in exposed animals. Follow these biosecure farm practices to reduce the risks of transmitting disease at your farm. Manure handling Many infectious agents pass in feces or urine of infected animals. To reduce the risk of spreading disease via manure, prevent contamination of feed and water, and clean resting areas daily.

 Plan and install a manure system to prevent environmental contamination and comply with Vermont’s Acceptable Agricultural Practices.

 Maintain clean water troughs, water bowls, and feed mangers.

 Use a separate skidsteer or loader bucket for manure and feed operations.

 Use separate shovels and forks for feeding and manure handling.

 Compost or store manure under conditions that destroy most disease- producing bacteria.

 Remove manure frequently from barns, yards, and holding areas to prevent completion of life cycles by intestinal parasites and flies.

 Control the fly population. Methods include flypaper, parasitic wasps, and insecticides.

 Store manure so it is inaccessible to livestock, especially young stock.

 Prevent runoff of adult manure to young stock rearing areas or contamination of feed fed to young animals. (This is especially important for Johne’s control.)

 Do not feed refusals from older animals to youngstock.

 Keep dogs and cats out of feeding areas.

 Clean teats and udders of livestock immediately before or after parturition (birthing) so nursing young will not ingest manure if birth is unattended.

 Remove young from dam as soon as possible, i.e. before a dairy calf or kid nurses.  Clean maternity areas between births. Equipment sanitation

 Clean and disinfect any equipment used on sick animals prior to use on healthy herd mates.

 Clean and disinfect dehorners, hoof knives, and clippers between animals.

 Use your own halters and clippers rather than borrowing them.

 Sanitize nursing bottles and buckets after each feeding. Employee sanitation

 Wash farm clothing with detergents and bleach or washing soda.

 Insist workers wash their hands before milking dairy animals and after working with sick animals. Nitrile gloves are recommended when frequent cleaning between animals is necessary.

 Insist workers wear protective plastic or rubber gloves when assisting with births. Farm traffic, animal transport, and sanitation

 Keep visitor and service vehicles from driving over feed delivery or manure handling routes if at all possible.

 Keep visiting vehicles out of areas accessible to livestock.

 Locate holding pens for animal pickups near the road and away from the barns or livestock areas.

 Use only clean well-bedded trucks to move livestock to avoid introducing diseases and to avoid injuries during transport.

 Thoroughly wash and disinfect the inside, outside, and tires of livestock-hauling trucks or other implements of husbandry shared with neighbors. Housing for different animal groups Young animals acquire infectious diseases primarily through exposure with older infected or carrier animals. To minimize disease transmission, housing and management systems should minimize contact between young stock and older animals. Younger animals need time to develop immunity to diseases. Although the following recommendations are written for cattle, similar principles apply to all livestock.

 Separate pre-weaned dairy calves from all other age groups.

 House each dairy calf in an individual pen or hutch.

 Place hutches away from dairy barn exhaust fans.

 House 4- to 8-month-old dairy calves in small groups separate from older heifers.

 House yearling and breeding age dairy heifers separately.

 Separate replacement heifers from cows.

 Separate dry dairy cows from milking cows.

 If overwintered on pasture, move cows to a clean pasture for calving.

 Milk mastitic, treated, or sick cows last, and disinfect the milking claw between such animals.

 Provide adequate pen, stall, or bedded area per animal.

 Provide adequate feed bunk length and water trough access per animal.

 Organize chore routines to feed and milk isolated cattle after the main herd.

 Make sure farm dogs and cats are vaccinated against rabies.

 Prevent fence-line contact between your stock and other animals. Maternity and sick pens

 Use maternity pens only for birthing animals.

 Move pregnant animals to clean pastures or paddocks prior to birthing.

 Use sick pens only for sick animals

 Segregate sick animals and prevent animal-to-animal contact between sick pens and maternity pens.

 Provide a clean environment for birthing. In cattle, this is important to prevent the spread of Johne’s and Salmonella, calf scours, and fresh cow mastitis.

 Clean all manure from the pens after use.

 Disinfect the walls and floors after use.

 Allow the pens to dry after disinfection.

 Bed the pens before the next animal enters. Pen/hutch disinfection

 Remove all bedding.

 Remove sidewalls, gates, hog wire, if applicable.

 Power wash or steam clean all wood, metal, or concrete surfaces.  Note: ammonia compounds should not be mixed with chlorine because the combination releases a harmful gas; acid compounds mixed with chlorine release toxic chlorine gas.  The hot water or steam will inactivate most pathogens.  Protect yourself from aerosolized material; wear goggles and a respirator.  Rinse with a chlorox solution for additional sanitization.

 If a high-temperature pressure washer is not available, scrub all surfaces with detergent, rinse, and rinse again with a chlorox solution.

 Let dry before bedding for next use. Feed storage and bunk management

 Make sure that feed bunks and storage areas are inaccessible to rodents, birds, dogs, cats, and other wildlife.

 Protect all feeding areas from animal carcasses and manure.

 Follow optimal feed management practices.

 Use smooth feeding bunks to minimize the surface area that could be colonized by pathogens.

 Dispose of feed refusals if not eaten within 24 hours. Do not feed refusals from adult animals to youngstock. This is an important Johne’s control measure.

 Check for and dispose of moldy or spoiled material in silos, bunks, and bins.

 Clean in and around storage areas between batches of feed.

 Rotate inventory to limit the amount of pathogens in stored feeds.

 Keep covers on barrels and bins; make sure water is not getting into storage areas.

 Address any moisture problems periodically. Ensure that the storage environment is appropriate for feed.

 Apply manure to forages well before harvest.

 Use optimal procedures for harvesting, handling, and storage of all crops. Water quality and trough management

 Clean water troughs, buckets, or cups daily or weekly. Replace with ones that are easier to clean if this is a bottleneck.

 Protect all water sources from animal carcasses and manure.

 Make sure a regular cleaning schedule of water troughs and tanks is being followed. Facility maintenance

 Replace fly tape if necessary.

 Be aware of hiding and denning places for rodents. Set baits or traps accordingly. Use caution if dogs access same area.

 Inspect and repair holes in buildings to prevent rodents from living there.

 Remove piles of boards, wood, or other junk.

 Check for rain and storm water damage.

 Identify and correct manure runoff problems.

 Remove standing water, which can be a breeding ground for mosquitoes.

 Prevent standing water on the ground near water systems in pastures.

 Check fences along farm and pasture perimeters; repair any damage. Use electric fence wherever possible, if appropriate.

 Make changes to bird detractors and fly tape or other control methods as needed.

 Replace bird netting where needed and change bird detractors so that birds do not ignore their presence. Boot cleaning and disinfection Farms set up footbaths with the goal of preventing mechanical transmission of pathogens among groups of animals. However, boot bath maintenance on most facilities is poor, with gross contamination by organic matter frequently observed. People commonly avoid stepping into boot baths or simply step through the bath without stopping to clean their boots. Organic material frequently inactivates or decreases the activity of disinfectants. Thus, it is important to remove visible contamination with soap and water to optimize the effectiveness of disinfection. Adopting the following best management practices will minimize the risk of tracking pathogens on footwear.

 Clean visible dirt off of boots before disinfecting.

 Use water and a brush over a well-drained area. A boot cleaning station (as pictured at right), in which a hose is hooked up to a brush, is an option.

 Soak boots in a clean solution of an appropriate disinfectant.

 Use label recommendations for dilution rate and exposure time.

 Select disinfectants based on on-farm efficacy, cost, ease of use, and environmental friendliness. (See guide to disinfectants on next 5 pages.)

Disposable boots work well if protection is only needed for brief time periods.

Photo: http://www.biosecuritycenter.org/bootdispr.htm Disinfection in On-Farm Biosecurity

Choosing a disinfectant is a complex process. There is no one best product for all situations. You must consider the disease risks about which you are concerned, the type of surface you wish to disinfect, the conditions under which the disinfectant will be used, and then select a disinfectant that best suits your needs. When using a disinfectant, it is important to consider the following points:

1. Most disinfectants won't work if the surface to be disinfected isn't clean before applying the disinfectant.  Organic materials such as soil, plant debris (like straw), milk, blood, pus, and manure often inactivate some disinfectants or protect germs from the disinfectant's active ingredients.

 Chlorine-based products are especially subject to this problem.

 Wash boots, equipment, or housing areas first with water and detergent.

 Use steam and high-pressure washers to clean porous surfaces.

2. Disinfectants vary considerably in their activity against the assorted germs—bacteria, viruses, fungi, and protozoa—associated with livestock.  Plain vinegar (4% acetic acid) will readily kill the Foot and Mouth Disease virus, but is not effective against Mycobacterium avium paratuberculosis (MAP), the cause of Johne's disease.

 Most commonly used disinfectants are not active against bacterial spores, which are the environmentally hardy life form of the germs that cause tetanus, blackleg, botulism, and anthrax.

 The spectrum of activity of various classes of disinfectants is shown in a chart later in this section. 3. It is important to select a disinfectant that will be active across a wide spectrum of germs under the conditions in which it will usually be used.

 Check the pH (acidity or alkalinity) of your water. Hard water can reduce or destroy the activity of some disinfectants.

 Use the recommended water temperature for dilution or maintain at the recommended ambient temperature to ensure optimal activity.

 Know the shelf life of the chemical or the age of the mixture. Some lose activity fairly quickly after being diluted.

 Record when you mix each solution of disinfectant and refresh regularly. A solution that has been contaminated by organic material like manure, will have decreased effectiveness.

 Wear protective equipment if indicated. Some chemicals, especially at full strength, may be toxic or cause damage to skin, clothing, or environmental surfaces.

4. Disinfectants must have sufficient contact time with the surfaces to allow them to kill the germs. The required contact time varies with the product and the germ. In any case, a quick splash of a dirty boot in a footbath is not likely to accomplish anything except to give a false sense of security.

 Allow sufficient contact time for the disinfectant to do its job.

 Follow label directions closely and do not mix different classes of disinfectants.

5. Disinfectants are not to be applied to animals directly, unless labeled for such use.

 Consult the label to make sure there are no warnings against using them around feeders and in animal quarters.

 Rinse disinfectants off after the appropriate amount of contact time if animals will have contact with the disinfected surfaces. Guide to Disinfectants

On most farms, disinfectants will be used in footbaths or for cleaning equipment and livestock premises. The most commonly used disinfectants fall into the following six classes. Iodophors (e.g., Betadine® and Weladol®)  Iodine compounds have been used as antiseptics and disinfectants for many years.  They are good disinfectants but are not as effective in the presence of organic debris.  Iodophors are generally less toxic than other disinfectants but can stain clothes and some surfaces.

 Keep away from metals and out of sunlight. These may inactivate iodophor compounds.

 Do not mix iodophors with quaternary ammonium disinfectants. This will inactivate them.

Chlorine & Chloramines (e.g., bleach, Halazone®)  Chlorine compounds are good disinfectants on clean surfaces and have a broad spectrum of activity.  They generally are more active in warm water.  They can be somewhat irritating and can be harmful to clothing, rubber goods, and some metals.  Chlorine-based disinfectants are generally compatible with soaps but should never be mixed with acids.

 Use only after removing organic matter to optimize their activity.

 Mix a new solution of chlorine at least every 24 hours. Most chlorine solutions are unstable and lose activity over time.

Chlorhexidine (e.g., Nolvasan® -S)  Active against many bacteria and viruses.  Not effective against spore-forming bacteria.  Use the formulation appropriate for what you are disinfecting. There are formulations appropriate for hand washing and sanitizing equipment such as Nolvasan® Skin and Wound Cleanser or Surgical Scrub and Nolvasan® Solution respectively.

Quaternary ammonium (e.g., Roccal DT)  The older quaternary ammonium compounds are good for some situations and relatively clean surfaces.  They will not be particularly effective against the Foot and Mouth Disease (FMD) virus or the cause of Johne's disease and have markedly reduced activity in the presence of organic material.  Some of the newer quaternary ammonium preparations have improved activity.  Compounds in this class usually have some detergent action; however, most are inactivated by contact with soaps or soap residues.

Phenolic compounds (e.g., One Stroke Environ®, Osyl®, Amphyl®).  Phenolics have good activity in hard water and in the presence of some organic material.  They are considered active against many bacteria, viruses, and fungi, including the bacteria that cause tuberculosis and Johne's disease.  They are not effective against the FMD virus.  They are good all-purpose disinfectants for farm use.

Per-oxygen compounds (e.g., Virkon S®, Oxy-Sept 333®  Oxidizing agents such as Virkon S® appear to have a wide spectrum of activity against many kinds of germs (including the FMD virus). They are relatively stable in the presence of some organic material.  Oxy-Sept 333®, based on peroxyacetic acid, has been EPA- approved for killing the FMD virus and is reportedly active against a broad spectrum of germs. General Use Disinfectants The following chart outlines the properties of disinfectants that are legal for general use in Vermont.

Chlorine & Quanternary Per-oxy Iodophors Phenols Chlorhexidine Chloramines ammoniums compounds

Gram + Good Good Good Good Some activity Good (Anthrax)

Gram – Some Good Good Good Some activity Good (Brucella) activity

Acid-fast Some Some Bad Good Some activity Good (TB) activity activity

Spores Some Some Bad Bad Some activity Good (Tetanus) activity activity

Viruses Some Good Variable Some activity Good Good (FMD) activity

Fungi Some Good Good Some activity Some activity Good (Ringworm) activity

Best pH Acid Acid Basic Acid Wide Range Acid

Activity with Fair to poor Very Poor Very Poor Excellent Good Good Organic Material

Residual Yes Yes No Yes Good Good activity (Bleach : no)

On equipment On equipment On equipment Common On clean On clean On clean On premises On premises On premises uses equipment equipment equipment In footbaths In footbaths In footbaths

This table has been compiled from information gathered from the following three sites. Virginia Polytechnic Institute and State University and Virginia State University http://www.ext.vt.edu/pubs/poultry/408-310/table1.html The Veterinary Service in Northern Ireland http://www.dardni.gov.uk/vetservice/biosecurity/biodisinfectanttable.htm Purdue University Cooperative Extension Bulletin PIH-80; reprints can be ordered through http://www.agriculture.purdue.edu/agcomm/campus/other/mdc/order.html FMD Disinfectants The USDA has compiled the following table for field use in the event of a Foot and Mouth Disease (FMD) outbreak.

Product Dilution Mixing Instructions Notes 5.25% Sodium 3% Add 3 gallons of Hypochlorite (NaOCI) chlorine bleach to 2 (household bleach) gallons of water; mix thoroughly. Acetic acid* 4-5% Add 6.5 ounces of Vinegar is a 4% solutions glacial acetic acid to 1 of acetic acid gallon of water; mix thoroughly. Potassium 1% Follow label instructions Virkon-S Peroxymonosulfate and Sodium Chloride (i.e Virkon-S) Sodium Carbonate 4% Add 5.33 ounces of The solution is mildly (soda ash)* sodium carbonate to 1 caustic but can dull paint gallon of hot water (or 1 and varnished surfaces. pound to 3 gallons of hot water); mix thoroughly Sodium Hydroxide 2% Add 1/3 cup of NaOH This solution is highly (NaOH) pellets (2.7 ounces of the caustic. Use protective (lye)* lye) to 1 gallon of cold rubber clothing, gloves water; mix thoroughly and safety glasses. WARNING: Always add the lye to the water. Never pour the water over the lye. * Section 18 application submitted and EPA approval pending. ** From National Emergency Response to a Highly Contagious Animal Disease, Executive Summary, March 30, 2001.

Although common household bleach would be an effective disinfectant for the FMD virus, the recommended concentration (3% sodium hypochlorite) is 60% of full strength as it comes from the bottle. This concentration would damage clothing, shoes, and rubber goods and is mildly corrosive to steel surfaces. It can be used on an infected premise in an outbreak of FMD, but probably wouldn't be a good choice as a general-purpose disinfectant for equipment and footbaths. Vinegar will also kill the virus, but wouldn't be a good choice for general use because of its lack of effectiveness against many other important germs. Obviously, lye is too caustic for general use. See the table on the previous page for disinfectants good for general use.