Patent Publication Number: US-2007101943-A1

Title: Electromagnetic Control of Pathogens in Poultry Production Facilities

Description:
BACKGROUND OF THE INVENTION  
      This invention relates to the method and apparatus for the treatment of poultry litter and other animal wastes to reduce the number of pathogens (bacteria, viruses, fungi, etc.) that affect poultry and/or human health and wellbeing. More specifically to the in place treatment of poultry litter by the use of electromagnetic energy in the frequency range of microwave, radio frequency or both to remove and/or reduce pathogens in the litter. This invention is a continuation in part of patent application Ser. No. 10/189,730 filed Jul. 3, 2002 and claims the benefit thereof.  
      Poultry and other livestock are commonly reared in confinement on a bedding material. The bedding material can consist of wood shavings, sawdust, rice hulls, peanut hulls, straw and recycled paper products, materials which are cellulosic in nature, in different mixtures and compositions. When animals are reared on this material the resultant combination of manure, bedding material, feathers, spilt food, etc., is referred to as “litter”. If broilers (meat chickens) are being grown, then broiler litter is produced. Similarly, if turkeys are being produced, then turkey litter is produced.  
      In a typical production facility about five or six flocks are grown each year on the same litter. In the spring the litter is cleaned out and applied to land as fertilizer, fresh bedding is placed into the houses, and the cycle is repeated. This reuse of the litter leads to a buildup of high levels of bacteria, viruses and fungi. These pathogens, such as  E. coli, Salmonella, Clostridium,  and  Camplyebacter,  are not only detrimental to the health and well being of the birds, many of them also pose a significant risk to human health. Food borne illness is a major problem in the U.S., particularly with poultry, and there are very few methods for controlling pathogen levels in poultry litter.  
      The litter may be buried, but this results in the possibility of contamination of the environs and ground water supplies. Steam sterilization of the litter before further processing is expensive and time consuming. The monitoring of the process for effectiveness is difficult and expensive. Dodd in U.S. Pat. No. 2,731,208 teaches a method of treating medical waste by shredding the waste and blowing steam into a container full of the waste. This is effective only for limited volumes and has an additional complication of depositing the shredded mixture into a sewer.  
      There are systems for treating waste utilizing microwaves. One system described in  The Wall Street Journal  (pg. B33, Apr. 10, 1989) picks up the waste, shreds it, sprays it with water and exposes it to microwaves in a chamber long enough to raise the temperature to 205 degrees C. This approach will not work for poultry litter because of the need to move the litter into an exposure chamber and then depositing it back into the beds. This increases the exposure to infectious particles and is expensive.  
      Kartchner in U.S. Pat. No. 5,980,824 describes a device to apply microwaves to animal waste in the form of semi-liquid manures. The device taught in this patent suffers from the same restriction as above as it requires movement of the pathogen laden material into an apparatus to treat with energy and then disposing of the treated material by such means as incorporating it into fertilizers. The present invention solves the need for movement of the waste and is capable of treating solid as well as semi-liquid waste in place.  
      Microwaves are limited in their penetration but are highly effective in the sterilization of the poultry litter. Their use has the advantage of control without leaving harmful residues or causing environmental pollution. There remains the problem of a contaminated floor that can re-infest the litter. Thus, there is a need for treatment of the floor that has the same advantage as the microwave treatment of the litter. Such treatment of the floor is well beyond the teaching of Karthner above as well as Geisler and Slone below.  
      Geisler, U.S. Pat. No. 6,872,927, teaches the generation of electromagnetic fields and application of the fields for processing pathogen-contaminated mail pieces. Thus the Geisler treatment requires the movement of the items to be treated. The present invention treats the target items in place.  
      Slone, U.S. Patent Publication No. 2003/021105, teaches a method for neutralizing anthrax and other bioagents with radio frequency and microwave electromagnetic fields. However, Slone is limited to situations utilizing an organic semiconductor in what is taught as being selected from the group of polydiazoaminityrosine (DAT) and diazoluminomelamine (DALM). The present invention solves the problem of neutralizing bioagents without depending upon the use of an organic semiconductor.  
      Wayland in U.S. Pat. No. 5,060,414 (Oct. 29, 1991) teaches the use of multiple frequencies in the control of unwanted vegetation. The underlying concept of the Wayland teaching is that, by combining in a specific application of multiple frequency electromagnetic fields, the destructive physiological response will be enhanced due to a more effective disruption of biological process. The present invention does not depend upon this effect as there is no biological process such as seed sprouting to disrupt in the litter. The use of multiple frequencies as taught in this invention is for the purpose of insuring that sufficient electromagnetic energy will be deposited in each segment of a litter bed and substrate (floor) to maintain control of unwanted pathogens in place without requiring removal of the litter before treatment and to solve the problem caused by the current treatment of applying a blow torch to the litter and/or substrate after the litter is removed which sometimes results in the burning down of the poultry facility.  
     SUMMARY OF THE INVENTION  
      Accordingly, it is an object of the present invention to provide a new and improved method of and apparatus for the reduction and control of unwanted pathogens in poultry litter and in the floor substrate without requiring the removal of the litter before treatment. To insure the necessary control in both the litter and the floor, two or more different frequencies of electromagnetic energy are used. At least one frequency in the microwave frequency band and another in the radio frequency band. A method and apparatus will be described that may be tuned to provide a preferred mixture of frequencies and energy levels for the reduction and control of unwanted pathogens in poultry litter and in the floor.  
      The control is achieved by two or more sets of transmitters and radiators, one in the radio frequency spectrum and at least a second in the microwave region. The radiators are set to apply directly, and in close distance, the electromagnetic field to the poultry litter. They are mounted on a cart or vehicle to allow positioning of the radiators over selected portions to be treated where they may remain for the selected duration without disturbing the litter. The power levels and duration of exposure are adjustable by the user to accommodate particular litter configuration and conditions. This application teaches that by using a combination of frequencies, treatment of both the litter and its floor can provide the reduction and control of unwanted pathogens in poultry litter. Depending upon the condition of the litter and floor, the frequencies chosen will be optimized to produce the most effective treatment. Thus, there maybe two, three or more frequencies applied in any given treatment.  
      Additional aspects and advantages of the invention will be set forth in part of the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. The advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims. It is understood that both the foregoing general description and the followed detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed. 
    
    
     DESCRIPTION OF THE INVENTION  
      The above and other embodiments of the present invention may be more fully understood from the following description and accompanying drawings.  
       FIG. 1  block diagram of a device that performs the method of applying at least two electromagnetic fields to poultry litter;  
       FIG. 2  flow diagram of the analysis for the proper configuration of the electromagnetic field applicator. 
    
    
      Referring to the drawing  FIG. 1 , a diagrammatic view illustrating the electromagnetic field generating equipment,  2  and  3 , the radiating elements,  6  and  7 , and the process control network,  10  for effective control of the application according to the teaching of this invention.  
      The products built according to the teachings of this invention may utilize standard radio frequency networks and devices, and standard microwave networks and devices well known in the art shown in  FIG. 1 .  
      The microwave (MW) electromagnetic fields (EMF) may be generated by means of magnetrons. The control and transmission of the energy and coupling into a radiator are well known in the art. It is critical that good safety practices are followed. The radio frequency (RF) EMF can be generated using standard commercial equipment. Depending upon the RF radiator employed, the RF EMF may be radiated as a uniform EMF over relative large areas. However, the MW EMF is highly directional and the radiator must be designed carefully to apply the MW EMF directly into the litter/floor media. The depth of penetration into the litter/floor is a function of wavelength and the electromagnetic properties of the litter/floor. The moisture content of the litter/floor is an important variable in determining the distribution of absorbed energy in the litter/floor. This invention teaches that the frequencies and radiation patterns of the applied EMFs should be chosen to optimize the absorption of energy so that the control of pathogens is maximized. Depending upon the conditions in the litter/floor, it may be important to deposit more EMF energy in either the litter or the floor.  
      To accomplish the best distribution of energy in the litter/floor a process similar to the flow chart shown in  FIG. 2  should be followed. Step  1 , will be to establish the environmental conditions in the production facility. These will include such data as the layout, the thickness of the litter, moisture content of the litter and of the floor, etc. Samples of the litter and the floor, as indicated in step  2  and  3 , will be assayed to determine what pathogens are present. These samples will then be prepared for testing in a controlled laboratory apparatus for exposure to Electromagnetic fields, step  4 . The exposure chambers used for testing must have the necessary environmental controls and the ability to make exposures over appropriate frequency ranges and power levels. Then using values from the open literature or from archives, database  6 , of previous tests as a starting point, determine, as indicated in step  5 , the electromagnetic properties of the samples as a function of frequency, composition, moisture content, etc. These measured values are archived, in database  6 , for use in future tests. Simultaneously or after these tests are run, a series of exposures should be made to determine the lethal dose,  7 , to kill 95% to 100%, i.e., the LD 100  of the pathogens. (LD 100  is the Lethal Dose to kill 100% of the pathogens.) These tests will be guided by the information in database  8 . At times this will be an overkill and a lesser kill percentage may suffice. These results are archived in the database  8  for use in future tests as the starting point in the next application.  
      The next steps,  9  and  10 , require the solution of Maxwell&#39;s equations. Depending upon the geometry of the radiating element, there are a number of standard analytic solutions (see J. R. Wait,  Electromagnetic Waves in Stratified Media,  New York: Pergamon, 2 nd  Edition 1970). It is also possible to obtain numerical solutions of the fundamental equations using computer integration techniques. Again, the results are archived in database  11  for future use. The databases  6 ,  8  and  11  are the accumulated. The results of this calculation will instruct the operator on the proper application of this technique to insure needed control of pathogens in the production facility.  
      As an example, when the above procedure was applied to a typical poultry raising facility it was found that a frequency of 433 MHz at 50 KWatts/SqFt followed by an application of 2450 MHz at 30 KWatts/SqFt at a speed of 4 Ft/sec would provide good control. Of course, this would not be the same for all applications. Each application would require analysis.  
      Clearly, after a body of knowledge is accumulated, not all of the above steps will be needed for each application. Only when new and uninvestigated situations are encountered will this entire lengthy procedure be necessary.  
      The toxicity of radio frequencies and microwave fields to pathogens (bacteria, viruses, fungi, etc.) is well known in the art. There are many possible mechanisms for this result. There is certainly a component associated with the increase in temperature, but there are also non-thermal effects. The actual mechanism of the phenomena is not well understood. Without specifying the precise mechanism it is the teaching of this patent that effective control of pathogens, in poultry litter and the floor upon which the litter rests, can be accomplished by the proper application of a multiple frequency electromagnetic field.  
      Since certain changes may be made in the above apparatus without departing from the scope of the invention herein involved, it is intended that all matter contained in the above description, as shown in the accompanying drawings, shall be interpreted in an illustrative, and not a limiting sense.  
     References  
      Greca et al., “Effect of radiofrequency energy on bacterial spores” Bacteriol. Proc., p.145 (1964); Fleming, P., “Effect of High Frequency Fields on Micro-Organisms,” Elec. Eng., Vol. 63(1), pp. 18-21 (1944); Chipley, J., “Effects of Microwave Irradiation on Microorganisms”, Adv. Appl. Microbio., vol. 26, pp. 129-145 (1980); Wait, J. R., “Electromagnetic Waves in Stratified Media”, Pergamon Press, 1970; Kaufman, A. A. and Keller, G. V., “Frequency and Transient Soundings”, Elserier Sci. Pub., 1983: Wait, J. R., “Geo-electromagnetism”, Academic Press, 1982; Lechowich, et al., “Procedure for Evaluating the Effects of 2,450 MHz Microwaves upon Streptococcus faecalis and Saccharomyes cereislae”, Applied Microbiology, vol 17, pp. 106-110, 1969; Wayland, et al., “On the Interdependence of Thermal and Electromagnetic Effects in the Response of Bacillus subtilis Spores to Microwave Exposure, Radiation Research, vol. 71, pp. 251-258 (1977)