Background of the Invention One of the most significant problems faced by the dairy industry is the cleaning and sanitizing of the equipment involved in the process of milking. The sanitizing is necessary to ensure not only the health of the consumers who drink the milk but also the health of the cows and other mammals who provide the milk. The physical environment of cows and other milk-producing mammals is far from being clean; they are often covered with mud, insects, agricultural debris and the like, and are constantly exposed to a wide variety of bacteria and other pathogens. As a consequence, the mammals themselves, in particular the udders and the teats, must be cleansed and sanitized prior to milking, to minimize the contamination of the milk drawn from them and to prevent infection of the mammary gland (mastitis) by bacterial contamination. In addition, the equipment used in the milking process, in particular the"teat cups"that are attached to the teats and which are part of standard pneumatic/mechanical automatic milking apparatus must also be properly cleaned and sanitized, so as to prevent the transfer of bacteria and other pathogens from one animal to the next and to prevent contamination of the milk as it is being conveyed to storage tanks.

Various methods are known and used in the dairy industry in connection with the cleansing and sanitizing of the equipment involved in the milking process. These include the washing of the udders utilizing streams of water under pressure, dipping or spraying the udders and teats with one or more bactericides, and the flushing and "back-washing"of the milking apparatus with water, detergents and the like.

However, at least two serious drawbacks have been encountered in the dairy industry when utilizing the known methods for sanitizing udders and associated

milking equipment. The first drawback stems from the fact that the various bactericides that have been certified for use by health authorities have a long "contact time", i. e. they must remain on the udders and other surfaces to which they are applied for a minimum of 25 seconds if they are to be effective. The second drawback stems from the fact that the bactericides and any other substance applied to the udders must be completely washed off prior to the milking, so as to prevent any residues from entering the milk itself. Both the long contact time of the certified bactericides and the need to wash off the bactericides from the udders and the associated milking equipment before each cow is attached to the milking machine result in a significant lengthening of the actual milking time of an average herd of cows (which may well number in the hundreds). For many dairy farmers, whose margin of profit is very small, this lengthening of the milking process is economically unacceptable. As a consequence, many dairy farmers do not sanitize their cows prior to milking, and merely rinse the udders with water. For the same reason, many dairy farmers do not sanitize the claws, teat cups and teat cup liners which come into contact with the cows, between the milking of one cow and another, and do so only after the whole herd has been milked. This practise significantly increases the probabilities that mastitis (infection of the mammary glands) or other diseases may be spread from one animal to another.

US Patent 5,211,961 describes a gel composition for cleaning and sanitizing the teats and udder of an agricultural animal for machine milking. In accordance with this patent, residual surface water, which is a source of milk contamination and mastitis, is eliminated from the teats and udder by use of the gel composition. The gel composition comprises water, a germicide added to the water in concentration sufficient to kill environmental bacteria which cause mastitis, an aqueous gelling agent, a soap or a detergent, and a skin softener. The composition is applied to the teats and acts as a cleansing and sanitizing agent; however, prior to milking, the gel must be wiped from the teats and the teats thoroughly cleaned prior to attachment to the milking machine.

US Patent 5,567,444 (to Ecolab) describes a method for cleaning and sanitizing soiled solid surfaces, especially in-place process facilities. The method involves contacting the soiled surfaces with an aqueous ozone cleaning composition

having a pH of at least 8 and comprising an effective ozone composition sufficient to produce an oxidation-reduction potential of at least +550mV with respect to an Ag/Agcl reference electrode, and then circulating an aqueous sanitizing composition containing hydrogen peroxide, a Cl-Clo peroxyaliphatic carboxylic acid or a mixture thereof sufficient to reduce the oxidation-reduction potential below about +400 mV.

One of the process facilities stated to be suitable for the use of such a method is a milk-line dairy.

Summary of the Invention The present invention provides a novel method for sanitizing the teats and udders of milk-producing mammals, as well as for sanitizing equipment utilized in the milking process, which overcomes the drawbacks inherent in the methods utilized today in the dairy industry. In particular, the present invention enables the sanitizing of the teats and udders, as well as the sanitizing of the milking equipment which comes into contact with the bodies of the mammals being milked, without the need to substantially interrupt the milking process so as to carry out the sanitizing process. The"contact time"is very brief and there are no traces or residues of potentially harmful bactericides. The method is particularly beneficial in enabling the sanitizing process to be carried out between the attachment of each cow to the milking machine, thereby assuring a much greater level of sanitizing than is obtained using conventional techniques. In addition, when using the present invention, it is possible to cut back significantly on the amount of water and detergents that need to be used in the cleansing and back-flushing of the milk line, such that the present invention is also economically advantageous for dairy farmers.

There is therefore provided in accordance with a preferred embodiment of the present invention a method for sanitizing the teats and udders of milk-producing mammals comprising the steps of (a) rinsing the teats and udders with water; and (b) applying a solution of ozonated water to the teats and udders. In accordance with a preferred embodiment of the invention, the ozonated water is applied by dipping the teats and udders in a solution of ozonated water or by the spraying of the teats and udders with a solution of ozonated water. Further in accordance with a preferred embodiment of the invention, the effective concentration of ozone in the ozonated water is between the range of 0.01 mg and 5 mg ozone per liter of water;

alternatively, between the range of 0.05 mg and 1 mg ozone per liter of water. In accordance with a preferred embodiment of the invention, the teats and udders of each mammal in the herd of mammals being milked is sanitized with the ozonated water immediately prior to the attachment of the mammal to the milking machine, and optionally also immediately after detachment from the milking machine.

As more fully described herein, the present invention also encompasses the use of ozonated water for the sanitizing of teats and udders of milk-producing mammals.

In accordance with a preferred embodiment of the invention, the ozonated water is applied by dipping the teats and udders in a solution of ozonated water or by the spraying of the teats and udders with a solution of ozonated water. Further in accordance with a preferred embodiment of the invention, the effective concentration of ozone in the ozonated water is between the range of 0.01 mg and <BR> <BR> <BR> <BR> 5 mg ozone per liter of water; alternatively, between the range of 0.05 mg and 1 mg ozone per liter of water. In accordance with a preferred embodiment of the invention, the teats and udders of each mammal in the herd of mammals being milked is sanitized with the ozonated water immediately prior to the attachment of the mammal to the milking machine, and optionally also immediately after detachment from the milking machine.

The present invention also provides a simple, effective method for preventing mastitis and other diseases of the mammary glands of milk-producing mammals, the method comprising the steps of (a) rinsing the mammary glands with water; and (b) applying a solution of ozonated water to the mammary glands. In accordance with a preferred embodiment of the invention, the ozonated water is applied by dipping the teats and udders in a solution of ozonated water or by the spraying of the teats and udders with a solution of ozonated water. Further in accordance with a preferred embodiment of the invention, the effective concentration of ozone in the ozonated water is between the range of 0.01 mg and 5 mg ozone per liter of water; <BR> <BR> <BR> alternatively, between the range of 0.05 mg and 1 mg ozone per liter of water. In accordance with a preferred embodiment of the invention, the teats and udders of each mammal in the herd of mammals being milked are rinsed with the ozonated water immediately prior to the attachment of the mammal to the milking machine, and optionally also immediately after detachment from the milking machine.

The present invention also provides an efficient method for sanitizing the teat cups and/or other components of a milking machine, the method comprising flushing the teat cups and/or other components with ozonated water. In accordance with a preferred embodiment of the invention the concentration of ozone in the water is between the range of 0.01 mg and 5 mg ozone per liter of water ; alternatively, between the range of 0.05 mg and 1 mg ozone per liter of water.

Detailed Description of the Invention The present invention utilizes the knowledge that has been developed concerning the powerful effect of ozone as an oxidizer and disinfectant, and applies this knowledge to the dairy industry. Ozone (CAS No. 10028-15-6) is a naturally occurring triatomic form of oxygen. It is a gas at both ambient and refrigerated temperatures. Ozone is produced naturally by the effect of solar ultraviolet radiation on atmospheric oxygen. The stable bonds of an oxygen molecule are cleaved into two short-lived oxygen atoms which react almost immediately with another oxygen molecule to form ozone. At ground level, ozone is produced when lightning is discharged through the atmosphere, and this is the cause of the familiar, fresh, clean smell of air following a thunderstorm.

Commercially, ozone has been in use for well over a hundred years in connection with the treatment of drinking water. As of 1993, there were more than 2,500 large scale water-treatment installations which utilized ozone as a means for purifying and treating water. Ozone is also used in the treatment of swimming-pool water and in the treatment of odors from industrial processes and municipal secondary effluents. Industrial high quality water supplies also are often treated with ozone, for example in breweries and in the production of soft-drinks Ozone is a powerful oxidant and as such is very useful as a disinfectant. It is considered to be the most efficient disinfecting agent for water, being more efficient than substances such as chlorine dioxide, hypochlorous acid, hypochlorite ion, dichloramine, and monochloramine.

Ozone is also a powerful bactericide. It attacks the bacterial membrane at the glycoproteins and glycolipids, or at certain amino acids such as tryptophan. It also acts on the sulfbydryl groups of certain enzymes, resulting in the disruption of normal cellular enzymatic activity. Bacterial death is rapid and has been attributed to

changes in cellular permeability in consequence of the high oxidant concentration.

Ozone further acts on the nuclear material of the bacterial cell by modifying the purine and the pyrimidine bases of nucleic acids. Ozone has been found to be effective against Gram-positive (including spore-formers) and Gram-negative bacteria, viruses, and protozoa.

Ozone has many applications in the food industry. It is used to increase the yield of certain crops, to protect raw agricultural commodities during storage and transit, and to sanitize water used for washing food equipment, foods, and packaging materials.

Ozonation is classifie by the United States Food and Drug Administration (FDA) as Generally Recognized As Safe (GRAS) for the treatment of bottled drinking water, when used in accordance with good manufacturing practices. The approved maximum residual level at the time of bottling is 0.4 mg of ozone per liter of bottled water. The use of gaseous ozone up to 0.1 ppm in meat-aging coolers has also been accepted by FDA. In 1997, an Expert Panel Report provided an unequivocal declaration of GRAS status for ozone for use in food processing.

One of the most important characteristics of ozone that make it attractive for use as a sanitizer in the food industry and elsewhere is that it does not leave any residues, since it does not remain in water for a very long period of time. As a consequence, ozonation may be considered to be a process rather than a food additive, with no safety concerns about possible consumption of residual ozone in food products. Any by-products that ozone may produce in the treatment of foodstuffs are similar to normal oxidation products, and thus are not likely to have deleterious health effects.

The inventors have discovered that ozonated water can also be used both efficiently and effectively as a sanitizer for the dairy industry, in particular in the sanitizing of the teats and udders of cows and other milk-producing mammals, and the sanitizing of the milking apparatus itself. Ozonated water, at a concentration of up to 5 mg/liter, is very effective in destroying the bacteria and other pathogens that are found on the udders of milk-producing mammals, and therefore is a highly effective sanitizer. The bactericide effect of ozonated water is almost immediate, such that it may be applied to the udders and teats immediately prior to the milking,

thereby assuring a very high level of sanitizing, without any concomitant lengthening of the milking process. In addition, as a consequence of the fact that ozonated water does not leave any undesirable residues, there is no basis for concern lest any artifact or other by-product of the sanitizing by ozonated water will contaminate the milk. In principle, there is no need to remove the ozonated water after it has been applied to the teats and udders; however, a simple rinsing with plain water may be done, if this is found to be desirable. Furthermore, because it is possible to apply the ozonated water to the udders with relative ease and speed, it is possible to do the sanitizing before each and every cow is attached to the milking machine, thereby achieving a degree of sanitizing that is not obtainable currently by conventional methods.

Optionally, so as to provide an additional degree of sanitizing, the udders and teats of each mammal may be rinsed again with ozonated water, after the conclusion of the milking and the separation from the teat cups.

The present invention is particularly advantageous in that it does not necessitate any substantive alteration of the milking process or of the milking machines currently in use. There are many commercially available ozone generators, such as Azcozon VMUS-4, manufactured by Azco Industries Limited (Surrey, British Columbia, Canada), and these may readily be adapted for use in the implementation of the present invention. The ozone generator may simply be attached by an injector in a conventional manner to the source of water that is used both for the cleansing of the mammals and the cleansing of the milking apparatus.

Prior to the attachment of each mammal to the teat cups, the udders and teats of the mammal are first thoroughly washed with plain water, and then thoroughly washed with ozonated water, with the ozonated water having a concentration of ozone sufficient to be an effective bactericide. A minimum concentration of 0.01 mg ozone per liter of water has been found to be necessary, and a concentration of up to 5 mg/liter is more than sufficient; preferably, the concentration is between 0.05 mg and 1 mg ozone per liter of water. The pre-milking washing and sanitizing may be done in any conventional manner, in the holding area, the sprinkler pen of the milking parlor or in the milking parlor itself, either by dipping the udder and teats in the ozonated water or by spraying the ozonated water on the teats and udders. In parallel, the teat cups themselves, including the liners, pipes and other hardware

associated with them are also thoroughly flushed with the ozonated water, thereby assuring that the equipment which comes into immediate contact with the mammals is thoroughly sanitized.

Ozonated water, in accordance with the invention, as described above, may be used effectively either in addition to or in place of other means of sanitizing currently used in the dairy industry. Because ozonated water is such an efficient bactericide, the use of ozonated water in accordance with the invention is also beneficial in the prevention of mastitis, and in preventing the spread of disease from one animal to the other, which often occurs today due to the fact that the teat cups are not sanitized after being use by each animal.

Ozonated water, in accordance with the invention, may also be used most effectively in sanitizing other component parts of the milking apparatus. Thus, after the whole herd has been milked and the collected milk has been emptied from the collection tank, ozonated water can be used to flush the whole system (including the bulk tank), preferably after a prior cleaning of the system with a detergent, as is conventionally done. And because ozonated water is such an efficient bactericide, when using ozonated water in accordance with the invention, significantly less water and detergents are needed for the proper cleansing and back-flushing of the milk line. Thus, the present invention not only provides a simple and efficient method of sanitizing, but it also provides significant economic benefits for the dairy industry.