Released Feb. 18, 2008
ST. PAUL, Minn. — Livestock manure contains many microorganisms such as bacteria, viruses and protozoa. Some microorganisms don’t cause sickness in animals or humans, while others are pathogens, meaning they’re capable of causing disease.
All livestock producers—regardless of the size of their farm—have an obligation to prevent the spread of pathogens from their operations to the environment. Human illness, and in rare instances death, can be caused by exposure to livestock manure.
Not all pathogens are the same. Some can survive for long periods of time in manure, while others are susceptible to temperature extremes and manure processing. That means multiple methods for reducing pathogens may be needed in a manure management system.
Producers can reduce pathogens at three stages in the manure management cycle:
- In the animal, through animal management and housing, and diet modifications.
- In manure collection and storage, through production management and chemical or biological treatments.
- By proper land application of manure.
Livestock operations of all sizes need to control runoff and leaching from stockpiled manure and open lots. Many producers already use biological treatments such an anaerobic storage in deep pits and composting that reduce pathogen survival in manure.
Diet modifications, installing vegetative filter strips, eliminating livestock access to open water, changes in animal housing and treating manure with lime may be economical for some producers, and should be evaluated on an individual basis. Other systems such as aeration of stored manure, anaerobic digesters and use of chemical treatments may not be feasible for small to mid-sized producers. Large producers may find these management practices more economical.
No matter what systems a producer is able to use, some simple practices should be added to routines. The best way to control pathogens from livestock operations may be to make sure that manure doesn’t get into surface waters. This is best done by not spreading manure too close to waters or tile inlets and incorporating the manure into the soil after application.
More information is available in a University of Minnesota Extension publication titled “Best Management Practices for Pathogen Control in Manure Management Systems.” You’ll find that publication and other information on manure management at http://www.extension.umn.edu/manure. Click on “Water Quality and Agriculture.”
Contacts: David Schmidt is an agricultural engineering specialist with University of Minnesota Extension.
Catherine Dehdashti, (612) 625-0237, firstname.lastname@example.org