WO2001050843A2

WO2001050843A2 - Low dust litter composition

Info

Publication number: WO2001050843A2
Application number: PCT/US2001/000774
Authority: WO
Inventors: S. Michael Hughes
Original assignee: Pet Care Systems
Priority date: 2000-01-11
Filing date: 2001-01-10
Publication date: 2001-07-19
Also published as: WO2001050843A3

Abstract

The present invention provides a litter composition that includes a particulate material and a dust reducing agent, the dust reducing agent being a vegetable oil. The invention also provides a method for reducing dusting tendency in a litter composition including selecting a particulate material and adding a dust reducing agent to the particulate material, the dust reducing agent being a vegetable oil. The invention further provides a corresponding litter arrangement for sorbing liquid animal waste, and a method for sorbing an aqueous liquid utilizing a litter composition.

Description

LOW DUST LITTER COMPOSITION

This application is being filed as a PCT International Patent application in the name of Pet Care Systems, a U.S. national corporation and resident, on 10 January 2001, designating Europe, Canada and Japan.

Field of the Invention

The present invention pertains to a low dust litter composition as a sorbent for aqueous liquids, as well as a method of reducing dusting tendency in a litter composition, and a method for sorbing aqueous liquids using a litter composition.

Background

The use of litter as a sorbent for pet animal urine and other waste liquids has been known for years. Typically, the litter is placed into a container or in an area which the pet has been trained to use for urinating and defecating. Many prior art litters have been derived from sand, clay, and other minimally sorbent materials. More recently the useful life and sorbency of these litters has been increased by addition of binders and other additives which cause a clump to form from litter soiled by urine and fecal liquids. See e.g., U.S. Patent Nos. 5,216,980 and 5,176,107. Formation of soiled litter into a clump, in part, minimizes the spread of urine or fecal liquids thus reducing bacterial contamination of the unsoiled litter surrounding the excreted waste liquids. At the same time, however, litters based upon such materials as clay often forms clumps that settle and consequently block sewer or septic lines when flushed down a commode. More recently, natural products such as grains, or cellulosic products such as sawdust, woodchips or plant hulls have been used as a litter. See e.g., U.S. Patents No. 4,206,718; 4,727,824; 4,883,021; 5,109,804; 5,152,250. These products were developed in an effort to enhance the sorbency of the litter as well as provide a biodegradable litter which could be flushed down a commode attached to a septic or sewer system. However, although biodegradable, some natural product litters tend to swell excessively when contacted with aqueous liquids and thus cause problems such as blocking the sewer or septic lines when flushed down a commode. In addition, after wetting, some prior art litters do not form a clump from the wetted (soiled) litter. The failure of soiled litter to form a clump makes it difficult to separate the soiled litter from the unsoiled litter, thus tending to cause greater contamination of the unsoiled litter. Therefore, analogous to the use of binders in minimally sorbent litters, some natural product litters have also relied on binders to cause formation of a clump. See e.g., U.S. Patent No. 5,152,250. However, the clumps formed by some of these litters often have a high tendency to crumble after drying. A litter which forms a clump which crumbles easily tends to leave soiled litter particles in the unsoiled litter during removal of the clump from the litter container or by the weight of a pet stepping on the clump prior to removal. This obviously increases the chances for contamination of the unsoiled litter.

Moreover, the clumps formed by some prior art litters often have poor attrition resistance. Poor attrition resistance may cause contamination of the unsoiled litter by soiled particles which are abraded from the solid clumps during removal of the clump from the litter container. Also, certain litters, after being wetted and dried, may not reform into a clump if broken and rewetted. The repeated contamination of unsoiled litter by particles of soiled litter results in a decreased useful life of the litter.

Furthermore, the process used to prepare some natural product litters causes the litter to take on a noticeable odor which may be unpleasant for the pet owner. An odor emanating from the litter may also prevent an animal from voiding in the litter container resulting in urination or defecation at places other than the litter container. This obviously can create problems for a pet owner sharing the same living space as the pet. Many prior art litters have a tendency to generate fine particles or dust. Such dust generation is undesirable for several reasons, such as health risks posed to the pet and owner, complications in the packaging processes, and build-up of dust in the home or office. Health risks posed by the generation of dust or fine particles can result from the inhalation or ingestion of the dust or particles. For example, clay- based litters generate silica dust, which is a known carcinogen. The inhalation of silica dust by the pet and/or owner thus poses risks associated with cancer. Pine- based litters, on the other hand, shed fine particles (e.g., that resemble small toothpicks) that can become embedded in the digestive tract of animals. Additionally, the dust generated by litters can create problems in the packaging process as a result of build-up of particles or dust on packaging machinery. Moreover, the generation of dust or particles in the living space is undesirable for both the pet and pet owner.

Thus, there exists a need for a litter composition that includes a dust reducing agent to reduce dust or other fine particles generated by the litter, wherein such desirable characteristics of the litter such as the appearance, odor, clumping, and the like are not adversely affected by the dust reducing agent.

Summary of the Invention The present invention provides a litter composition comprising a particulate material and a dust reducing agent, the dust reducing agent comprising a vegetable oil. Preferably, the vegetable oil is a grain oil, and more preferably, the vegetable oil is soybean oil.

The particulate material of the litter composition comprises a grain or non- grain material. In one embodiment, the particulate material is provided in the form of ground grain. In this embodiment, the invention provides a litter that has a low tendency for generating dust, odor and swelling. Additionally, the litter is scoopable, flushable, and has a low tendency for attrition. The litter is harmless if ingested by animals, and is non-irritating to pets, e.g., animals that have recently undergone surgery.

According to the invention, a litter includes a dust reducing agent comprising a vegetable oil. The dust reducing agent provides such advantages as substantial reduction of dust or fine particles generated by the litter, without adversely affecting such desired characteristics of the litter as the appearance, odor, and/or clumping ability. Moreover, the vegetable oil is edible.

The dust reducing agent of the invention can be used with virtually any particulate material in litter compositions. In one embodiment, a litter is composed of a particulate material that comprises a ground grain. Preferably, the ground grain is derived from wheat varieties including white wheat, spring wheat, winter wheat, durum and combinations thereof. In another embodiment, the particulate material comprises non-grain material, such as sand, clay, natural grass compositions, cellulosic compositions, wood, newspaper, and the like.

The present invention can be used to sorb liquids, for example, aqueous liquids, oils, animal wastes, and human fluids. In a preferred embodiment, the litter of the invention may be used to sorb aqueous animal waste of a pet which lives in a home, apartment, office space or other building structure which may be shared with humans.

The invention further provides a method for making a low dust litter composition, as well as an arrangement for sorption of aqueous animal waste which is composed of a litter container having the litter contained therein.

Detailed Description

The present invention provides a litter composition that includes a particulate material and a dust reducing agent. The invention includes the use of a litter composed of a dust reducing agent which causes the litter to have a tendency to generate low dust. This in turn makes the litter safer and more appealing to the pet and pet owner. Moreover, the shelf life of the litter composition is preferably extended by the inclusion of the dust reducing agent, since the dust reducing agent can prevent the litter composition from drying out. Preferably, the litter is composed of a particulate material that is prepared by a process which causes the litter to have a low odor. When soiled by an aqueous liquid, the particulate material of the invention tends to form a low attrition clump which is easily separated from the surrounding unwetted litter. Moreover, when contacted with aqueous liquids, the particulate material of the litter has a lower tendency to swell thus making it less likely to plug sewer or septic systems when flushed down a commode.

As used herein, the phrase "particulate material" means a major sorbent material that is a base material. As discussed in more detail below, the particulate material includes grain and non-grain materials. Particulate materials can be used with or without binders and other additives which cause a clump to form from litter soiled by liquids, e.g., urine and fecal liquids. Preferred litter contains a majority, for example, at least about 50% by weight, more preferably about 70% by weight, and most preferably about 75 % by weight, of particulate materials that are in a size range between about 250 and about 25,000 microns.

In one embodiment, the litter product can include a natural agent to reduce the dusting tendency of the ground grain litter, for example, milo. Milo can be provided as a modified whole grain such as IGP Polymer RD-3330 which can be obtained from Industrial Grain Products, P.O. Box 3520, Lubbock, Texas 79452.

In an alternative embodiment, the litter composition can include a "dust reducing agent." As used herein, "dust reducing agent" means a compound that substantially reduces the dusting tendency of the litter. According to the invention, using the methods described in the examples as well as comparable measuring methods, the dust content of the litter composition is preferably about 0.5% by weight or less, more preferably, 0.1% by weight or less.

In one embodiment, the dust reducing agent of the litter comprises vegetable oil. Preferred vegetable oil is grain oil. As used herein, "grain oil" is any oil product that is produced from a grain source. A preferred grain oil is soybean oil. The application of a dust reducing agent provides benefits in the processing plant (e.g., by improving plant and employee safety, as well as reducing operating costs), and in the home (e.g., by reducing the amount of dust in the litter box). The present inventor has observed a reduction in the "free floating flour" in the processing plant. After the dust reducing agent was applied to the particulate material, the plant was much cleaner, which provided employees a more safe work environment and greatly reduced the time needed to clean the plant each day.

The application of the dust reducing agent also reduced the amount of flour that was exhausted out through the processing plant's negative air system. Each machine and bin has a negative air flow which draws flour out of the processing into the screenings bin. The present inventor has observed that the amount of flour that is drawn into the bin has been reduced approximately 50% to approximately 65% (this amount varies based upon the moisture content of the wheat being processed). This in turn provides a more cost effective process for producing a low dust litter composition, as the screenings tanks are emptied less often, and employee time is saved. The present invention also provides important benefits in the home. The application of the dust reducing agent allows flour particles in the litter composition to adhere to the particulate material and fractured starch particles contained in the litter composition. The application of the dust reducing agent thus substantially reduces dust in the litter box.

Suitable dust reducing agents provide such characteristics as substantial reduction of dust from the litter, edibility, and wide application to all types of litter compositions. Moreover, the dust reducmg agent does not adversely affect such desired characteristics of the litter as appearance, odor, and clumping ability. By reducing the dusting tendency of the litter composition, the invention also provides an improved method of packaging litter products.

Suitable vegetable oils are grain oils. Suitable grain oils include soybean oil, corn oil, canola, sunflower oil, and the like. A preferred grain oil is soybean oil, and in a particularly preferred embodiment, the soybean oil is provided as an extruded soybean oil, such as commercially available from Hi-Fat Specialties Company, Jasper, Minnesota.

The dust reducing agent can be added to the litter in any suitable manner, for example by spraying, coating, rinsing, and the like. In a particularly preferred embodiment, the dust reducing agent is applied to the litter composition as a fog under air pressure and oil pressure. The air and oil pressures applied during application of the dust reducing agent vary depending upon such variables as the moisture content of the material being processed.

In one preferred embodiment, for example, soybean oil can be applied to 2,000 pounds of a ground grain litter as a fog under air and oil pressure. The soybean oil is applied to the ground grain to reach an equivalent of 0.25 % by weight of the litter product. Pressure conditions for this application are approximately 30 psi (air) and approximately 36 psi (oil). Alternatively, when the dust reducing agent is added to 3,000 pounds of ground grain, to reach an equivalent of 0.25% by weight of the litter product, conditions are approximately 48 psi (air) and approximately 42 psi (oil). Optimally, the dust reducing agent is applied to the particulate material as the litter composition enters the bagging bin. In this embodiment, the dust reducing agent is added as the last step prior to bagging the final litter composition product. The amount of dust reducing agent included in the litter product can be adapted for particular applications. For example, the amount of dust reducing agent included in the litter composition can vary depending upon moisture content of the particulate material comprising the litter. For particulate materials such as wheat or corn, which have a variable moisture content that is relatively high, less dust reducmg agent may be required. On the other hand, for a particulate material such as clay, which has a relatively lower variable moisture content than the above materials, less dust reducing agent may be required.

Preferably, when the particulate material comprises a wheat material, the dust reducing agent content of the litter composition is approximately 0.1 % to approximately 2% by weight. More preferably, the dust reducing agent content is approximately 0.25% to approximately 1.5% by weight. Most preferably, the dust reducing agent content is approximately 0.25% to approximately 1% by weight. While it may be appreciated that higher amounts of dust reducing agent may be used, the amount of dust reducing agent included in the litter composition may be limited to the extent that the agent causes undesirable characteristics, such as excessive clumping of the litter. Additionally, it will be appreciated that lower amounts of dust reducing agents may be used than the above stated amounts.

The particulate material of the invention can be provided in the form of a grain or a non-grain material. In one preferred embodiment, the particulate material of the litter is provided as a ground grain. In this embodiment, the ground grain utilized in a litter of the present invention is not used as a binder which is added to another litter material to cause clumping. However, it will be appreciated that the present invention can be used with such particulate materials as those disclosed in U.S. Patent No. 5,361,719 which discloses a litter composition which is composed of a ground grain liquid permeable base and a high gluten hydrating media.

The ground grain litter of the invention is suitable for sorbing any aqueous liquid. In a preferred embodiment, the ground grain litter is useful for sorbing aqueous animal waste. As used herein, the phrase "aqueous animal waste" means animal urine and aqueous liquids associated with fecal material which are voided by an animal. Typically, litters of the present field of the invention are used for sorption of pet animal wastes, for example, a cat. In a preferred embodiment, the litter is placed into a litter container in which the pet has been trained to enter to urinate or defecate. The litter container, which contains the ground grain litter, is situated such that it may be contacted by an aqueous liquid. In practical terms, this means that the litter container is placed in a location accessible for the pet to void whenever necessary when housed in a home, apartment, office space or other building structure where humans and pets share the same space.

The litter container may be made of any material which is impervious to aqueous animal waste. The size and shape of the container is variable, but usually it is at least large enough for the pet to enter into and move around, but is not so large as to prevent lifting of the container by a person for disposal of the soiled litter. Usually the container has a bottom and sides which are high enough to maintain a depth of litter sufficient to surround the litter and sorb the voided aqueous animal waste.

Typically, a container has a volume capacity of 1 to 5 liters. As used herein, a "ground grain litter" is a litter composition containing ground grain. The ground grain is provided in the litter at greater than 30% by weight ground grain, preferably greater than 80% by weight ground grain. If the ground grain litter is made up of less than 100% of ground grain, the nonground grain portion of the litter may be composed of any other known or later discovered litter material. The nonground grain litter component may also contain compounds which function to mask or neutralize waste odors, provide an attractant for the animal, inhibit bacterial growth, or other similar nonsorbent function.

As used herein, the phrase "ground grain" means whole raw grain which is prepared using a process which is described in detail below. As used herein, the phrase "whole raw grain" refers to a whole grain kernel as it comes out of a harvesting device typically used in harvesting agricultural products, for example, combines and threshers. Often the whole grain kernel coming out of a harvesting device will have associated with it chaff and stalk remnants. These remnant materials may or may not becOme part of the ground grain litter. Whole raw grains which may be selected for use as a ground grain of the invention include, for example, cereal grains such as wheat, sorghum, barley, rice, oats, rye, triticale, millet, corn and other grains for which "cereal grain" is a generic term. The ground grain may be prepared from a single whole raw grain or combinations of one or more whole raw grains which may be combined before or after the grinding process. Preferred cereal grains of the invention may be selected from the group of wheat varieties including white wheat, spring wheat, winter wheat and durum. A particularly preferred wheat variety is hard red spring wheat.

The ground grain litter is prepared by grinding whole raw grain, and optionally combining the ground grain with another litter material and/or other nonsorbent compounds. According to the invention, the ground grain is prepared from whole raw grain which has a moisture content of up to 20% by weight, preferably about 10-17% by weight, most preferably about 13% by weight.

Prior to grinding, the whole raw grain is put through a cleaning device to remove foreign materials including stones, rocks, metal, dirt, dust, weed seed and other nongrain material. Such cleaning devices are known in the grain grinding art and include, for example, magnets, disk cleaning mills, sieve cleaning mills and similar devices. The grain may then optionally be subjected to deinfestation using an infestation destroyer. The order in which the grain is cleaned and deinfested is not important. Infestation destroyers are known in the art.

After the grain is cleaned and deinfested it is subjected to a single or dual head roller or a hammer mill to crash the whole grain into a smaller particle size. When using a roller mill, the rollers are set apart at about 0.002 to 0.025 inch, preferably about 0.008 to 0.0018 inch. This amount of spacing between rollers tends to produce a majority of particles which are in a size range between 250 - 2,500 microns. If a hammer mill is used, an appropriate mesh size is used to produce ground grain having a majority of particles in a size range between 250 - 2,500 microns. After the grain is crushed (ground) it moves into a sifter where large particles are separated by passing through a mesh sieve and returned to the roller or hammer mill until the proper particle size is achieved.

The sieve mesh size used in the sifter is 8-100 mesh, preferably 10-12 mesh. The mesh sizes are in terms of U.S. Standard Sieve Series, Fine Series of 1940 (10 mesh = 2000 microns sieve opening, 50 mesh = 297 microns, 100 mesh 149 microns). Typically, the oversized ground grain is returned to the mill about 2-4 times to achieve a homogeneous particle size. In a preferred embodiment, at least 75% by weight of the particles are from about 250-2500 microns. Once the desired particle size is achieved the ground grain is ready for use in a ground grain litter of the invention.

Unlike processes used to prepare some natural grain litter products, the process used to prepare the ground grain of the present invention does not add moisture during grinding. However, if the whole raw grain used to prepare the ground grain is at a moisture level below about 10%, water may be added to the whole raw grain prior to grinding to minimize the dust content of the final product. Similar to U.S. Patent No. 5,230,305, a ground grain of the present invention typically has a bulk density of about 350 kg/M³ to 900 kg/M³. When a preferred ground grain is prepared according to the invention, it will generally have a bulk density of about 550kg/M³. Also, a ground grain prepared according to the invention generally has a reducing sugar content of about 0.1% by weight to about 2.5% by weight. A preferred ground grain prepared according to the invention generally has a reducing sugar content of about 0.5% by weight. The cold water solubles content of a ground grain prepared according to the invention is about 10-70% by weight. A preferred ground grain prepared according to the invention has a cold water solubles content of about 30%) by weight.

The method used for determining the bulk density of the ground grain of the invention is described in Example 1. The method used to determine the reducing sugar content is known in the art and described in " AOAC Official Methods of Analysis," Association of Analytical Chemists, Method 925.42 (15th ed.). The method used to determine the percentage of cold water solubles is known in the art and described in "Standard Analytical Methods of the Member Companies of the Corn Refiners Association, Inc.," Standard B-56, Corn Refiners Association, Inc., 1100 Connecticut Avenue, N.W., Washington, D.C. 20036 (6th ed.)

Upon contact with aqueous liquids, the ground grain of the present invention tends to form a low attrition clump. As used herein, the phrase "low attrition clump" means a clump which, after drying, loses less than about 15% of its weight, preferably less than about 10% of its weight, when subjected to attrition testing. The test used to determine the percent attrition of a clump formed by the ground grain of the invention is described in Example 6. Low attrition clumps are advantageous because they are less likely to lose particles of soiled litter when the clump is removed from the surrounding unsoiled litter in a litter container. This property of a litter is also advantageous in preventing particles of dry soiled litter from breaking off of a soiled clump if subjected to compression by an animal stepping on the clumps while moving around in the litter, h addition, the clumps formed by the ground grain of the invention are capable of reforming on contact with an aqueous liquid if broken after forming. A low attrition clump provides a significant advantage over prior art litters by increasing the useful life of the litter through decreased contamination of unsoiled litter by particles falling away from the soiled clump into the unsoiled litter.

It has been observed by the inventor that when a preferred litter composition is prepared according to the process used in the invention, the litter composition emits a minimal odor. It may be theorized that a high odor litter composition is due to certain specific agents or compounds present in the material. It may be further theorized that reducing and/or removing compounds used in preparing a litter which are responsible for the odor will result in an improved litter. For example, a wheat grain litter prepared according to a method disclosed in U.S. Patent No. 5,230,305 has a characteristic "burnt wheat" smell. Removal or prevention of forming of agents responsible for such smells provides an improvement over such prior art litters.

The identification, isolation and quantification of an odor from a litter product can be a very complex process. That process becomes even more complex when it is desirable to standardize and correlate subjective sensory evaluation data with quantitative analytical data. However, certain methods are known and usable to reliably accomplish this task. Such methods are known and have been described, for example, in U.S. Patent No. 5,137,744, column 5, line 51 through column 7, line 48 which is incorporated herein by reference. Although testing was not performed, it is believed that by using such methods, the litter composition of the present invention will be found to have a lower odor relative to some prior art litters. It is further believed that this feature enhances the desirability for household use of a litter product. Also, when contacted with aqueous liquids, the litter of the invention tends to swell less than some other ground grain based litters. As used herein, "swell" means the tendency of the litter to increase in volume when contacted with an aqueous liquid. This attribute is particularly beneficial if the soiled litter is flushed down a commode attached to a sewer or septic system. By using a litter which swells less upon contact with aqueous liquids, sewer or septic systems have less tendency to become blocked or plugged when the litter is flushed down a commode. The ground grain litter of the present invention has been certified as flushable by the SGS U.S.

Testing Company, Inc., Tulsa, Oklahoma. The method used to determine the swelling of a preferred ground grain of the invention is described in Example 5. A ground grain litter of the invention tends to swell less than about 100% when contacted with aqueous liquids, preferably, less than 70%. As used herein, a ground grain which swells 100% means that the ground grain doubles in volume upon contact with water using the method described in Example 5. While the inventors do not wish to be held to any single theory, it is believed that many of the properties of the present litter are, in part, a result of the milling process used to prepare the litter. Unlike some milling processes which may impregnate the particulate material with gas and moisture prior to grinding, the preferred process used to prepare the litter composition of the present litter is, relatively speaking, a drier process which causes an increased amount of damaged starch post grinding. It is believed that the high quantities of fractured starch provide, in part, the advantageous properties.

Other suitable grain-based particulate materials include grains that have a similar starch and protein content to the above-described grain. The starch content can provide clumping characteristics of the litter composition, while the protein content can provide low odor characteristics of the litter. Suitable grain-based particulate materials include grain sorgum and the like.

In an alternative embodiment, the litter of the invention comprises a non- grain material. As used herein, "non-grain material" is a material containing compounds that are not grain based compounds. Examples of non-grain materials include sand, clay, gravel, natural grass compositions, sawdust, woodchips, or cellulosic products. Examples of suitable natural grass compositions include alfalfa and other chlorophyll-containing compositions. According to the invention, cellulosic products include cereal grain kernels, such as oat, rice, wheat, rye or corn hulls; peanut hulls; soybean; rapeseed; sunflower; cottonseed hulls; corn cobs; corn kernels; corn stover; and the like.

The following examples will further describe the method for preparing a ground grain litter of the invention and the tests performed to determine the various characteristics of the litter.

EXAMPLES EXAMPLE 1

Preparation of a ground grain litter and determination of ground grain particle size in microns.

500 lbs. of raw whole red spring wheat was cleaned. The wheat was put through a single head roller mill with the rollers having a gap of 0.010 inch. The resulting grain was passed through a sifter contaimng a 10 mesh sieve 3 times. The resulting ground grain was then analyzed to determine particle size, bulk density, percentage cold water solubility and reducing sugar content. Table 1 shows the particle size distribution of a 200 gram sample of the ground grain litter. As seen in Table 1, approximately 95%> of the particles are within a size range of about 250 to 2,500 microns.

TABLE 1 PARTICLE SIZE DISTRIBUTION

EXAMPLE 2

Determination of ground grain litter particle size in terms of sieve mesh size.

Ground grain was prepared from raw whole hard red spring wheat as described in Example 1. The particle size of the ground grain litter was determined using various sieve mesh sizes. The resulting particle distribution is shown in Table 2.

TABLE 2

EXAMPLE 3

Determination of bulk density of a ground grain litter.

The bulk density for the ground grain litter prepared in Example 1 was determined by dividing the weight in grams of a sample by the volume of the sample in milliliters. After the sample was weighed, it was put into a measuring cylinder and tapped gently until no further settling was observed. The volume was then read. Three different bulk densities were determined from different locations in the sample and are shown in Table 3.

TABLE 3

BULK DENSITY OF GROUND GRAIN LITTER

The average bulk density of this sample is about 552.6 kg/m³.

EXAMPLE 4

Determination of % cold water solubility.

The percentage cold water solubility for the sample prepared in Example 1 was determined using Standard B-56 in "Standard Analytical Methods of the Member Companies of the Corn Refiners Association" (6th ed.). The test was run four times on a single sample and an average value calculated.

TABLE 4 PERCENTAGE COLD WATER SOLUBILITY

The average cold water solubility for the 4 samples was 29.02 + 1.73.

EXAMPLE 5

Determination of percentage swelling of ground grain litter when contacted with water.

For purposes of describing the percent swelling of the ground grain of the invention, the following method was used. A pre-weighted glass or plastic container was filled to a predetermined volume (41 ml), with a ground grain sample. The sample and container were weighed and water was added intermittently as it was sorbed until an excess of water laid over the grain sample. The sample was allowed to sit for 20 minutes. Final volume of the ground grain in the container was measured in milliliters and the wetted grain was then removed from the container without disturbing any remaining nonwetted grain. The container was then inverted and the dry grain removed, screened through a 10 mesh sieve, and weighed. The dry volume of wetted litter was calculated. From this the percent volume increase due to wetting was calculated. Results are shown in Table 5.

TABLE 5

EXAMPLE 6

Determination of the attrition of clumps of hydrated litter.

For purposes of describing the attrition resistance of the clumps of ground grain formed on wetting the grain, the following method was used. Clumps of hydrated ground grain were formed by wetting the litter with 6 grams of water and allowing the sorbed water to set for five minutes. Thereafter the clumps formed were carefully removed from the nonwetted litter and dried. The dried clumps were weighed. The attrition was then determined by carefully removing the bonded but poorly adhering particles on the surface of the clumps by gently rubbing a finger across the surface and weighing the particles removed. The results are shown in Table 6. TABLE 6

All patents in the specification are indicative of the level of ordinary skill in the art to which this invention pertains. All patents are herein incorporated by reference to the same extent as if each individual patent and publication was specifically and individually indicated by reference.

EXAMPLE 7

Addition of Vegetable Oil to Litter. Vegetable oil was added to a particulate material to make a litter composition of the present invention as follows. Particulate material was provided in the form of hard red spring and hard red winter wheat. Extruded soybean oil (available from Hi- Fat Specialties Company, Jasper, Minnesota) was added to the particulate material in amounts equal to 0.25% by weight, 0.50%> by weight, 0.75% by weight, and 1.00% by weight of the litter product.

The oil, particulate material, and the combined oil/particulate material samples were divided into three samples each. A representative sample was maintained at room temperature (approximately 25°C) and two others af a controlled temperature (approximately 60°C) (Schaal Test). These samples were sniffed on a daily basis to detect any odor exuded by the litter product.

Oxidation of the soybean oil was measured by evaluation of peroxide value (PV) of the oil. One sample of the oil was kept at room temperature (25°C) and the other was held at the controlled temperature (60°C). Peroxide values were not evaluated on the oil/particulate material samples due to the small percentage of oil in each sample, as well as the possibility that the starch in the wheat could interfere with the results.

Results indicated that there was little difference noted regarding odor in the oil/particulate material samples throughout the week, whether room temperature or oven temperature. However, both the 1.00% and 0.75% oil inclusion samples appeared wet (darker hue) whereas the 0.50% and 0.25% oil inclusion samples did not.

As expected, the heated oil sample developed a roasted nut (but not foul) odor. The peroxide value (PV) analyses showed low oxidation of the oil. Generally, in soy oil, 1.0-5.0 PV is considered low oxidation, 5.0-10.0 PV is considered moderate oxidation, and 10+ PV is considered high oxidation. The initial PV of the extruded oil was 3.05 meq. peroxide/kg fat. By the end of the week, the PV was 3.73 meq. peroxide/kg fat (room temperature), and the heated oil PV was 25.65 meq. peroxide/kg fat. The extruded oil was not stabilized via chemical means, and therefore degradation of the oil was expected at 60°C.

From the results, it was determined that for optimal results using the hard red spring and hard red winter wheat ground grain litters, 0.25% by weight soybean oil be included with the particulate material. This percentage of oil sprayed on the product appears to suppress the dust without adversely affecting the appearance, odor, and clumping ability of the litter composition.

EXAMPLE 8

Determination of dust content in litter composition containing dust reducing agent.

For purposes of describing the dust content of the litter composition of the invention, the following method is used. A pre- weighed measuring cylinder is filled to a predetermined volume with a litter composition sample. The filling process is achieved by gently pouring the litter composition into the measuring cylinder, to avoid agitating the litter and thereby generating dust. The sample and cylinder are weighed. The cylinder is placed under a vacuum hood, the vacuum hood including a screening chamber having a removable, pre-weighed screen. A negative air pressure is generated in the vacuum hood, and the litter composition is poured from the measuring cylinder into a second, empty and clean measuring cylinder. While the litter composition is poured, therefore, the negative air pressure pulls the air and dust through the screening chamber. The negative air pressure generated in the vacuum hood is sufficient to pull air and dust in the hood, thereby collecting the dust generated by the litter composition in the screening chamber. The negative pressure can be from about 10 to about 100 torr.

After waiting ten (10) minutes, a visual inspection is performed to ensure that the litter composition is no longer generating dust. Once it has been confirmed that no dust is being generated, the negative air pressure is turned off, and the screen from the screening chamber is removed and weighed. The dust content of the litter composition is calculated by dividing the amount of dust captured by the screen, by the amount of litter measured in the first measuring cylinder.

According to the invention, the dust content of the litter composition is preferably about 0.5 % by weight or less, more preferably, 0.1% by weight or less.

It will be apparent to one of ordinary skill in the art that many changes and modifications can be made in the invention without departing from the spirit or scope of the appended claims.

Claims

WHAT IS CLAIMED IS:

1. A litter composition comprising:

(a) a particulate material, and

(b) a dust reducing agent, the dust reducing agent comprising a vegetable oil.

2. The composition according to claim 1 wherein the particulate material is of a particle size such that at least 75% by weight of the particulate material consists of particles in a size range of 250-25,000 microns.

3. The composition according to claim 1 wherein the particulate material comprises ground grain.

4. The composition according to claim 3 wherein the ground grain is selected from white wheat, spring wheat, winter wheat, durum, or combinations thereof.

5. The composition according to claim 1 wherein the particulate material comprises non-grain material.

6. The composition according to claim 1 wherein the vegetable oil comprises grain oil.

7. The composition according to claim 6 wherein the grain oil is selected from soybean oil, corn oil, canola, or sunflower oil.

8. The composition according to claim 1 wherein the dust reducing agent comprises 0.25% to 1% by weight of the litter composition.

9. The composition according to claim 1 wherein the litter composition has a peroxide value of 1 to 5.

10. The composition according to claim 1 wherein the dust reducing agent is edible.

11. A method of reducing dusting tendency in a litter composition, the method comprising:

(a) selecting a particulate material; and

(b) adding a dust reducing agent to the particulate material, wherein the dust reducing agent comprises vegetable oil.

12. The method according to claim 11 wherein the particulate material comprises ground grain.

13. The method according to claim 12 wherein the ground grain is selected from white wheat, spring wheat, winter wheat, durum, or combinations thereof.

14. The method according to claim 11 wherein the particulate material comprises a non-grain material.

15. The method according to claim 11 wherein the vegetable oil comprises grain oil.

16. The method according to claim 15 wherein the grain oil is selected from soybean oil, corn oil, canola, or sunflower oil.

17. A litter arrangement for sorbing liquid animal waste, the arrangement comprising:

(a) a litter container; and

(b) a litter composition comprising particulate material and a dust reducing agent comprising vegetable oil, the litter composition being contained in the litter container.

18. The litter arrangement according to claim 17, wherein the particulate material comprises ground grain.

19. The litter arrangement according to claim 18, wherein the ground grain is selected from white wheat, spring wheat, winter wheat, durum, or combinations thereof.

20. The litter arrangement according to claim 17 wherein the particulate material comprises a non-grain material.

21. The litter arrangement according to claim 17 wherein the vegetable oil comprises grain oil.

22. The litter arrangement according to claim 21 wherein the grain oil is selected from soybean oil, corn oil, canola, or sunflower oil.

23. A method for sorbing an aqueous liquid utilizing a litter composition, the method comprising the steps of:

(a) selecting a particulate material;

(b) providing a dust reducing agent into the particulate material of step (a), the dust reducing agent comprising a vegetable oil; and

(c) situating the particulate material of step (b) to be contacted by an aqueous liquid to be sorbed.

24. The method according to claim 23 wherein the particulate material comprises ground grain.

25. The method according to claim 24 wherein the ground grain is selected from white wheat, spring wheat, winter wheat, durum, or combinations thereof.

26. The method according to claim 23 wherein the particulate material comprises a non-grain material.

27. The method according to claim 26 wherein the vegetable oil comprises grain oil.

28. The method according to claim 27 wherein the grain oil is selected from soybean oil, corn oil, canola, or sunflower oil.

29. The method according to claim 23, wherein the aqueous liquid contacted with the ground wheat grain litter in the step (d) is aqueous animal waste.