Animal litter

An absorbent material suitable for animal litter includes a mixture of (a) from about 10% to about 65% by weight pine wood; (b) from about 5% to about 60% by weight alfalfa; and/ (c) from about 15% to about 75% by weight poplar wood, preferably aspen.

FIELD OF THE INVENTION 
This invention relates generally to the field of animal litter mixtures, 
and, more particularly, to an absorbent material that includes a mixture 
of pine wood, poplar wood and alfalfa. The absorbent litter material is 
characterized by a pleasant odor, durability, good absorption, and is 
especially suitable for use as a small animal litter, which effectively 
absorbs animal waste materials and neutralizes associated unpleasant 
odors. 
BACKGROUND OF THE INVENTION 
Previously, it has been known to use aspen particles, chips, shavings etc 
as a litter for animals. However, this material has traditionally often 
been composed of all aspen, without other woods or substances introduced. 
Further, these 100% aspen litters were composed of essentially all 
portions of the tree, including the bark. Although such "litters" are 
suitable for use as horticultural mulch, the inclusion of the tree bark 
causes an appearance which is considered to be unsightly when the material 
is used as a litter, and particularly a litter for small animals, such as 
those which would be kept in a person's home, or for use in places of 
display, such as pet shops. 
Other litter compositions including alfalfa or related forage crops are 
known for their utility as animal litters which effectively absorb animal 
waste materials and neutralize associated unpleasant odors. For example, 
alfalfa has been pelletized with starch, as disclosed in U.S. Pat. No. 
3,923,005. Such pellets overcome the disadvantage of earlier pelletized 
alfalfa by reducing the problem of disintegration of the pellets, which 
caused the litter material to cling to the animal's feet. 
A further improvement of alfalfa pellets was disclosed in U.S. Pat. No. 
3,941,090 which discusses pelletizing cedar in combination with alfalfa 
binders. 
U.S. Pat. No. 4,788,936 discloses pelleted bedding for livestock, which 
bedding includes 4 to 45% by volume of aspen bark, with the balance being 
a combination of sawdust, ground wood chips and ground lumber. U.S. Pat. 
No. 5,271,355 discloses absorbent material formed of pelleted poplar wood, 
preferably aspen, including the tree bark, and peat. Optionally, the 
material may also include cedar wood. 
All of the above references involve absorbent materials that are completely 
pelletized. However, the process of pelletization is complex and thus 
expensive. Aspen is especially difficult to pelletize, because it is a 
hard, dry wood which exacts a toll on the extruding equipment used for the 
pelletizing process, by causing greater amounts of wear on the equipment 
parts, resulting in the expense of frequent maintenance and replacement. 
SUMMARY OF THE INVENTION 
Thus, because of the above less-than-ideal characteristics, which are 
common in known small animal litter mixtures, it is among the objects of 
the present invention to provide an absorbent material which is useful as 
an animal litter particularly well-suited for small household pets, which 
is simple to prepare, and thus relatively inexpensive, while also being 
highly absorbent of both liquids and odors and having an aesthetically 
pleasing appearance. 
It has been discovered that a particular mixture of certain known 
substances results in a litter which, while useful for large animals as 
well, is surprisingly well-suited for use with small animals, such as the 
type often considered for household pets, such as guinea pigs, monkeys, 
mice, gerbils, birds, hamsters, etc. The presently conceived small animal 
litter is a mixture of alfalfa, optionally in the form of pellets, and 
pine wood chips, shavings or the like (particularly yellow pine which has 
been dyed green in color), and, most advantageously, barkless aspen chips, 
shreds or shavings. 
This particular blend of ingredients has a pleasing "natural" green and 
white appearance and is light-weight, and highly absorbent of odors and 
fluids. This ability to absorb fluids and odors is particularly high as a 
relative ratio of fluids and odors per weight unit of the new litter 
mixture, when compared to known litters. This advantage of the new litter 
is attainable, in large part, because of the use of aspen and even more 
especially because of the use of barkless aspen wood, which is unusually 
lightweight. Thus, the new litter mixture is more pleasant to have in a 
home environment for use with pets, particularly when the person caring 
for the animal happens to be a small child or an elderly or other 
individual who cannot readily lift heavy containers of known pet litters. 
The new litter mixture is also well-suited, for example, for pet stores, 
zoological parks or other displays frequented by many people, some of whom 
may be especially easily offended by the odor of animal urine or the 
appearance of soiled cage litter. 
Accordingly, in order to accomplish the above goals, the present invention 
is, briefly, an absorbent material suitable for use as an animal litter 
and which is composed of a mixture of: 
(a) from about 10% to about 65% by weight pine wood; 
(b) from about 5% to about 60% by weight alfalfa; and 
(c) from about 15% to about 75% by weight poplar wood. 
Other goals and advantages will be in part apparent and in part pointed out 
hereinbelow.

DETAILED DESCRIPTION OF THE INVENTION 
The present invention involves an absorbent material made of a mixture of 
pine wood, alfalfa and poplar wood. 
The pine wood of the present invention is splinters, chips, saw dust, wood 
particles, pine shavings or other wood waste material. The preferred pine 
wood is pine shavings. Optionally, all or part of the pine shavings can be 
dyed, usually green, to provide a more aesthetic appearance. The amount of 
pine wood in the absorbent material is from about 10% to 65% by weight. 
The preferred range is from about 10% to about 40% by weight. The most 
preferred range is from about 15% to about 30% by weight. 
The alfalfa of the present invention is optionally, but not necessarily, 
pelleted, with the size of the pellets in the range of about 0.50 to about 
0.05 inches in diameter. Preferably, the pellets of from about 0.20 to 
about 0.10 inches in diameter. The amount of alfalfa in the absorbent 
material is from about 5% to 60% by weight. The preferred range is from 
about 5% to 40% by weight. The most preferred range is from about 15% to 
30% by weight. 
The poplar wood of the present invention can be any poplar-type wood, for 
adequate results. However, the preferred poplar wood is aspen, because of 
the exceptional absorbency of this particular poplar. The most preferred 
poplar wood is debarked aspen particles, or pieces, which have greater 
absorbency than aspen bark, are lighter in weight, and have a more 
pleasing appearance for a litter, being lighter in color. Aspen is also 
known to be lower in oil content than other woods and provides a less 
fertile ground for bacterial growth, thus keep odors in soiled litter to a 
minimum. The preferred aspen particles are of a large enough size to not 
adhere to the animal's feet, yet small enough to provide sufficient 
surface area for enhanced absorbency. The preferred size of the particles 
is in the range of about 10 to 30 mesh. The most preferred range is from 
about 15 to 25 mesh. This preferred size is the most well suited for small 
caged animals. 
The preferred range of aspen or other poplar wood in the new animal litter 
is from about 15% to about 75%. The particularly preferred range of aspen 
is from about 20% to about 45% by weight. 
The absorbent material of the present invention is a mixture of the above 
three components, aspen, alfalfa and pine. Optionally, components such as 
cedar wood, deodorants, perfumes, dyes, or additional absorbent components 
can be added to the absorbent material. However, for purposes of economy, 
the new litter mixture can used without any additional components, with 
more than satisfactory results. 
The following example is provided as an illustration of a typical 
embodiment of the product of this invention and is not intended in any way 
to limit the scope of the invention to the specific constraints therein 
described. 
EXAMPLE 
An absorbent material is made of the following components (all components 
are by weight): 
______________________________________ 
50 parts of pine shavings, dyed green - 
9% 
50 parts of pine shavings - 
9% 
308 parts of aspen particles - 
57% 
133 parts of alfalfa pellets - 
25% 
______________________________________ 
The aspen particles are formed of debarked aspen wood and 85% of such 
particles are greater in size than 20 mesh. The alfalfa pellets are 0.187 
inch in diameter. Such a mixture will give a highly suitable result for 
use as a litter for small caged animals in absorbency of both liquids and 
odors, and is very light in weight. 
In view of the foregoing, it will be seen that the several objects of the 
invention are achieved and other advantages are attained. 
Although the foregoing includes a description of the best mode contemplated 
for carrying out the invention, various modifications are contemplated. 
As various modifications could be made in the composition herein described, 
without departing from the scope of the invention, it is intended that all 
matter contained in the foregoing description shall be interpreted as 
illustrative rather than limiting.