Biosecurity depends on a set of programs and procedures that will limit the buildup and spread of harmful microorganisms and pests on farm. The goal is to inhibit the movement of infectious agents that are harmful to animal production.
With respect to manure management, biosecurity depends on a set of programs and procedures that will limit the buildup and spread of harmful microorganisms and pests on farm. The goal is to inhibit the movement of infectious agents that are harmful to animal production. The following article is an in-depth examination of biosecurity issues in manure management. While every farm may not be able to implement all of the suggestions in this article, potential problem areas can be determined.
Facility site selection is the most important aspect of manure management. Unfortunately, for many producers, the site was selected long-ago. While most biosecurity efforts deal with protection of a particular farm’s cattle, farms should also strive to reduce the impact of their manure on the neighbors.
For additional or new facilities, the old adage “out of site, out of mind” is a good one to remember. Avoid adjacent lands with residential development, commercial facilities, recreational use areas, near waterways and other non-agricultural lands. If avoidance is impossible, siting of other facilities or using crops or trees as natural screens can help.
Odor is a major source of neighbor complaints. Remember that non-farm neighbors often equate odor with a health risk. Evaluate warm season direction of airflow to control smells and insects from the public venue. Tree barriers and hedgerows may help diminish air movements, allowing gases a greater chance to rise vertically and enter the atmosphere.
Soil properties are important in manure application and lagoon construction. An erosion control plan to stabilize the soil is essential. Depending on local regulations, a nutrient management plan to balance manure application with crop needs might be required. Seasonal restrictions on manure spreading may also be legislated for some or all soil types. Location of the manure facilities should be determined by a number of factors including; soil type both at the facility site and in fields, storage structure, method and timing of manure applications, constraints due to custom operator or labor availability, and minimizing the structure’s visual and odor impact on the surrounding community. In many cases, some of these factors will conflict. In such cases, farm management must decide where to compromise.
Pollution control and manure management facilities must be maintained away from environmentally sensitive areas like streams, drainage canals, lakes and wetlands. Farm facilities constructed on high ground will allow more wastewater management options. Biosecurity failures can occur any time manure-contaminated run-off enters cattle housing or feeding areas. Accidental contamination of the cow’s water source with manure has also be implicated in a number of disease outbreaks.
Manure Storage and Treatment
Manure needs to be evaluated from two perspectives. The first is nutrient conservation for maximum fertilizer value. The other is nutrient reduction and/or concentration for increased efficiency as well as reduced storage and spreading costs. In both cases, it is important to recognize the possibility that spreading manure helps to spread one or more diseases throughout the farm.
Systems that focus on nutrient conservation frequently employ manure lagoons or other long-term storage facilities. Settling and/or holding basins may be placed prior to lagoons for the separation of solids and/or sand bedding. Liquid manure spreaders or slurry irrigation systems move the nutrients to crop acreages for application. Application systems that expose manure to UV light can diminish the disease load.
Manure systems concerned with nutrient reduction frequently employ solids separation as a way to export nutrients off-farm. Manure solids which are properly composted have a greatly reduced pathogen load. Anaerobic lagoons, storage basins and holding ponds may be used to concentrate nutrients or convert their chemical form. Under some management schemes, lagoons can reduce odor levels. Long-term manure storage allows for scheduling of manure application to coincide with crop needs. This will, in turn, decrease the effect of manure nitrogen and disease agents on ground water.
Anaerobic bio-gas generation systems are frequently employed to reduce odors. In addition, there is some evidence that the process of bio-gas generation will reduce pathogen loads in the manure.
Agronomic plans are generally concerned with getting the correct amount of nutrients to field crops at the proper time. With increasing levels of regulation, balancing nutrient application rates with crop uptakes is becoming more important. A number of factors go into producing an agronomic plan, including:
- Manure characteristics
- Soil types
- Application rates
- Manure application timing
- Manure application equipment
- Crop utilization
- Field prioritization
Biosecurity and disease control are generally not considered to be part of the agronomic plan. However, manure applied to cropland must be viewed as a potential source of pathogens that can undo management efforts to control disease incidence. Therefore, agronomic plans must also consider whether manure application to a particular crop at a particular time poses a biosecurity or disease control risk.
Scheduling Manure Application
Apply nutrients as near to the period of plant uptake as possible while avoiding potential contamination of feed with manure-borne pathogens. Each farm’s pathogen concerns will differ, so this becomes a farm by farm and field by field decision.
Lagoon liquids are more efficiently used when there are several smaller applications throughout the season. Bare land application should be minimized as risk for pollution of ground water and run off is high. In addition, local regulations may restrict or prohibit manure application to bare ground. Cropping plans should strive to allow for a more or less season-long application of manure.
Incorporating Biosecurity Concerns in Manure Management Planning
When most dairy managers think about how to apply manure, they focus on the equipment side and how equipment choice will impact costs, hauling time, soil compaction and odor. Custom application may be considered from a cost, convenience or timeliness perspective. Biosecurity concerns add a further layer of considerations; specifically that manure application does not increase the cows’ exposure to pathogens.
Farm biosecurity plans document diseases that are present on the farm and which of these diseases are targeted for eradication. From a biosecurity perspective, manure management plans are specifically concerned with those diseases that can be spread by contact with manure. Don’t forget that manure may contaminate water, pasture, and forage. Be aware of the potential for neighboring farm(s) manure to contaminate adjacent fields or water sources.
In developing your plan, consider the following:
- Which manure-borne pathogens are you trying to control?
- Which classes of animals (calves, heifers, cows) are at risk?
- Where might each class of animal be exposed to manure that might contain disease causing agents?
- Is the pathogen in question likely to be eradicated by UV light, drying, storage and/or composting of manure, ensiling of feedstuffs, etc.?
- How long is the pathogen likely to persist in the environment?
Bovine Diseases Spread Via Manure:
- E. coli
- Johne’s disease
Bovine Diseases Spread by Manure-Contaminated Water:
- E. coli
- Johne’s disease
Bovine Diseases Spread by Manure-Contaminated Pasture or Forages:
- E. coli
- Johne’s disease
Manure and Disease:
Feedstuffs can introduce disease by fecal contamination. Do not use manure-handling equipment to handle feed. High pressure washers are important in the cleaning of equipment, since effective disinfection requires a CLEAN surface. Zoonotics diseases (animal diseases which can cause disease in people) are a particular concern with contaminated feedstuffs and water.
Application of manure and lagoon water to growing forages can cause contamination of animal feeds. Therefore, manure application should be limited to time periods to well before harvest. This will reduce the transmission of Salmonella, E. coli and Johne’s disease. Composting manure can be an additional help in reducing contamination of crops with disease-causing organisms.
Bacteria can survive for one year in un-composted manure. If possible, apply manure on crop fields not hay fields. Manure from trucks of unknown status should be avoided.
Manure from exhibitions or other dairies should not be spread on hay or pasture fields
Biosecurity Control Points for Dairy Manure
In developing a biosecurity plan that deals with manure application, here are some points to consider:
- Maintain a truck/tractor log of where vehicles have been in the last 48 hours
- Establish a traffic pattern for vehicles between farms
- Wash and disinfect the tires of vehicles before entering livestock areas
- Recognize and report disease
- Manure and manure hauling is the highest risk for disease transmission
- Vehicles should be clean and free from visible manure on tires and wheel wells
- Spreading equipment should be completely cleaned and disinfected between farms
- Disposable gloves, boot covers and coveralls can help keep equipment clean and prevent the spread of zoonotic diseases
- Hands and forearms washed with disinfecting soap
- In sensitive areas, consider a wash/disinfect in and wash/disinfect out procedure
- Manure hauling equipment should not be shared between farms without through cleaning and disinfecting
Total Cleaning and Disinfection Procedure
The basics of disinfection are:
- Manure and organics removed
- All equipment should be cleaned and disinfected before and after use
- Scrape, scrub and clean all equipment
- Remove all dirt, debris and manure
- Always clean and disinfect with approved products at the recommended dose; increasing concentration will not increase effectiveness
- Spray clean at a minimum of 200PSI (200-600)
- For disinfection and rinsing, remember to start at the top and work towards the bottom – don’t let potentially contaminated liquid drip onto clean areas
General Summary of Biosecurity Guidelines
A written plan or program is the first step to an effective biosecurity program. Your biosecurity program must be emphasized with ALL employees and custom operators. Biosecurity plans generally increase the amount of time spent on tasks; understand that continuous monitoring for adherence will be necessary. Educate workers to understand that good sanitization practices means good biosecurity. Include systematic cleaning and disinfection of equipment, as well as cleaning and maintenance schedules in your sanitization/biosecurity procedures.