TECHNICAL FIELD OF THE INVENTION
The present invention relates to the field of animal husbandry,
and more particularly to a detector apparatus used to detect when an animal is in
estrus (heat), and more particularly to a pressure responsive detector that can
be reset, such that the detector is reusable.
BACKGROUND OF THE INVENTION
It is typically desirable in the field of animal husbandry
to selectively breed livestock. This breeding may be done by mating selected animals,
artificially inseminating an animal, or any other suitable method. However, any
breeding method used entails determining when the animal is in heat in order for
insemination to fertilize the animal. The heat cycle is of a short duration and
insemination must occur during the cycle. The accurate detection of estrus is a
long recognized problem. If a pregnant cow is inseminated she is very apt to abort
her calf. This problem makes false positives very expensive. With a false negative,
the hot cow's breeding is delayed 21 days. This problem costs the dairyman $3.00
per day or $60.00 on each false negative.
Typically, when an animal, for example, a cow, is not in
heat, she will not allow herself to be mounted. Conversely, when a cow is in heat,
the cow will show an increased tendency to stand and permit itself to be mounted
by other animals for an appreciable time. When the mounted animal allows the mounting
animal to remain for about five seconds, a "standing mount" has occurred and the
cow is classified as in standing heat. This condition occurs in the early stages
of estrus. The most frequent mountings occur by bulls, but mountings are also made
by other cows. Accordingly, the repeated mounting of a cow by any other such animal
is a good indication that the cow is in heat. Cows must be mounted at least three
times before safe to breed.
The identification of cows in heat has traditionally been
accomplished by observation, the cows seen to allow mounting by other cows being
separated from the herd. While visual inspection and observation of a herd may be
employed to identify and segregate females in heat, because the heat cycle is of
short duration, such visual observation must be conducted multiple times during
a day and accompanied by immediate segregation or marking of the animals to be inseminated.
Visual observation of the herd, which is often widely dispersed, is typically inefficient.
Further, if no indicating device is used, unless the herd is maintained under constant
visual observation, the heat cycle may go undetected in many animals.
A variety of devices have been developed for indicating
when an animal is in heat by detecting when the animal has been mounted. Automatic
indicators have been used that are attached to the top rear section of the animal
between the hip-bone and spine and are set off by other animals mounting the animal
in heat. Typically, the indicators rely on the pressure exerted by the chest or
brisket of the mounting animal. A common indicator of this type includes a passive
apparatus including a reservoir of marker fluid which is compressed by the mounting
pressure to discharge some or all fluid and thereby mark the mounted animal. Frequently,
these devices suffer from incidental seepage of the marker fluid. This seepage can
result in an undesirably short shelf-life of the product. Further, the prior devices
involve complicated dye packet devices that are undesirably complex and expensive.
A need has thus arisen for a detector for determining when
a cow is in heat, wherein the detector is automatic and accurate for indicating
when a cow has been mounted for a time equal to or greater than a predetermined
time. A need has further arisen for a pressure responsive estrus detector which
can be reset whereby the detector can be reused multiple times.
SUMMARY OF THE INVENTION
In accordance with the present invention, a pressure responsive
estrus detector adapted to be secured to a first animal in a position to be contacted
by a mounting animal for indicating when the first animal is in heat is provided.
The detector includes a housing having a first and second oppositely disposed side
walls. A first interior wall is disposed within the housing and connected to the
first side wall to create a first fluid chamber. The first interior wall has a top
and bottom and an aperture disposed adjacent to the top. A second interior wall
is disposed within the housing and connected to the second side wall to create a
second fluid chamber. The second interior side wall is disposed adjacent to the
first interior side wall. The second interior side wall has a top and bottom, aligned
with the top and bottom of the first interior side wall. The second interior side
wall includes an aperture disposed adjacent to the bottom. Fluid is disposed within
the housing and flowable between the first and second fluid chambers via the first
and second interior wall apertures by pressure applied to either one of said side
walls by the mounting animal.
BRIEF DESCRIPTION OF THE DRAWINGS
For a more complete understanding of the present invention
and for further advantages thereof, references is now made to the following Description
of the Preferred Embodiments taken in conjunction with the accompanying Drawings
DESCRIPTION OF THE PREFERRED EMBODIMENTS
- FIG. 1 is an illustration of a rear view of a cow including the present detector
secured in position for use:
- FIG. 2 is a top plan view of the present detector;
- FIG. 3 is an exploded perspective view of the present detector illustrated in
Fig. 2; and
- FIG. 4 is a cross-sectional view taken generally along section lines 4-4 of
Referring to the Figures, Figure 1 illustrates the rear
view of a cow 10 on which the present estrus detector, generally identified by the
numeral 12 is mounted. Detector 12 is positionally and selectively insertable within
a holder 14 which is secured in a position near the backbone and above the rump
of cow 10 using a double sided adhesive canvas pad 14a, it being understood that
other methods of affixation can be utilized to affix holder 14 to cow 10. Detector
12 is mounted in a position such that when cow 10 is mounted , the relatively hard
brisket of the mounting animal compresses detector 12 against the backbone area
of cow 10, and such that gravity acts on the fluid contained within detector 12.
Should this compression continue for a predetermined time, detector 12 will provide
a visible indication which may be observed to indicate that cow 10 is in heat. The
use of detector 12 makes it possible to mark cow 10 without the continued presence
of an attendant to observe a herd, time the mounting, and mark cows.
Referring to Figures 2-4, detector 12 includes a housing,
generally identified by the numeral 16 having a top 16a and bottom 16b. Housing
16 is positioned within holder 14 in one of two positions with top 16a toward the
head of cow 10 or with bottom 16b positioned toward the head of cow 10. Housing
16 includes a first side wall 18 and second side wall 20 which are joined together
to form a fluid tight enclosure for a fluid 28. Side walls 18 and 20 comprise a
transparent material of plastic, or other suitable flexible material. Side walls
18 or 20 come in contact with the mounting animal, mounting cow 10.
Disposed within housing 16 and adjacent to first side wall
18 is a first interior wall 22. Interior wall 22 and side wall 18 are sealed to
form a first fluid chamber 24 within housing 16. First interior wall 22 includes
a top 22a and a bottom 22b. Adjacent to top 22a of first interior wall 22 is an
aperture 26. Aperture 26 allows fluid 28 present within housing 16 to flow into
and out of chamber 24. Fluid 28 may comprise, for example, colored ethylene glycol.
Also disposed within housing 16 is a second interior wall
30. Second interior wall 30 and second side wall 20 are sealed to form a second
fluid chamber 32 disposed within housing 16. Second interior wall 30 includes a
top 30a and a bottom 30b. Disposed adjacent to bottom 30b of second interior wall
30 is an aperture 34. Aperture 34 allows fluid 28 to flow into and out of chamber
32 within housing 16.
Fluid 28 flows within housing 16 from chamber 32 outwardly
via aperture 34 and into chamber 24 via aperture 26 upon pressure being applied
to first side wall 18. Conversely, when fluid is present within chamber 24, fluid
flows outwardly from aperture 26 into chamber 32 via aperture 34 when pressure is
applied to side wall 20. The present detector 14 is reusable do to the ability of
fluid to flow between chambers 24 and 32, and the selective repositioning of housing
16 within holder 14.
In operation, with housing 16 mounted within holder 14
such that top 16a is positioned in the direction of the head of cow 10, fluid is
retained within the bottom portion of second chamber 32. Second side wall 20 is
positioned adjacent to cow 10, and first side wall 18 is exposed to pressure exerted
by the mounting cow. When pressure is exerted on first side wall 18, fluid is forced
out of second fluid chamber 32 via aperture 34, and enters first fluid chamber 24
via aperture 26 to collect at the bottom portion of fluid chamber 24. Each time
the mounting cow exerts pressure on first side wall 18, a predetermined amount of
fluid flows from second chamber 32 into first chamber 24 thereby allowing first
fluid chamber 24 to fill up, and thereby provide an indication of the number of
times cow 10 has been mounted. First side wall 18 and second side wall 20 include
measurement indicia 40 which can be used to provide a visual indication of the number
of times cow 10 has been mounted. Fluid flowing into first fluid chamber 24 fills
first fluid chamber 24 from the bottom near indicia 40 towards the top 16a of housing
When cow 10 has been mounted a sufficient number of times,
all or most of fluid 28 will be depleted from second fluid chamber 32 and will be
stored within first fluid chamber 24. When it is desired to reset detector 12 for
reuse, detector 12 is removed from holder 14 via slot 14b and replaced into holder
14 such that bottom 16b of housing 16 is positioned towards the head of cow 10.
In this position, fluid 28 is positioned in the bottom portion of fluid chamber
24, first side wall 18 is positioned adjacent to cow 10, and second side wall 20
is positioned to receive pressure from a mounting cow. As cow 10 is mounted, fluid
28 flows from first fluid chamber 24 via aperture 26 into second fluid chamber 32
via aperture 34. Second fluid chamber 32 now fills as cow 10 is mounted due to pressure
being exerted by the mounting cow on second side wall 20 each time cow 10 is mounted.
Detector 12 is reusable because fluid 28 flows between chambers 24 and 32. Detector
12 is reset by presenting a fluid chamber 24 or 32 in an empty condition for contact
with the mounting cow, such that fluid is forced from the full chamber 24 or 32
adjacent to cow 10 when pressure is exerted on the opposing, empty, chamber 24 or
32 by the mounting cow.
Other alteration and modification of the invention will
likewise become apparent to those of ordinary skill in the art and upon reading
the present disclosure, and it is intended that the scope of the invention disclosed
herein be limited only by the broadest interpretation of the appended claims to
which the inventor is legally entitled.