CA2163593A1 - Separating pigs of a required market weight - Google Patents

Abstract

A system for separating pigs which achieve market weight from a group of pigs comprises a pen which is located at the regular drinking water trough for the pigs within the raising pen. The pen is arranged so that when the animals are approaching market weight they must enter the pen for drinking and the pen includes a floor plate with a load cell for detecting the weight of the animal. The pen is dimensioned so that only a single animal at a time can enter the pen and is then weighed. The pen includes a first gate which is normally closed and a second gate which is normally open so that the animal backs out when finished drinking. When the animal achieves a weight greater than the required market weight, this is detected by the load cell and the gates are moved to open the first gate and close the second gate to allow the animal to pass through into a holding pen.

Description

`- 2163~93 SEPARATING PIGS OF A REQUIRED MARKET WEIGHT
BACKGROUND OF THE INVENTION
This invention relates to an apparatus and method for selecting and separating those pigs from a group of pigs which have achieved a required market weight.
It is important in today's high productivity, high efficiency hog producing facilities that the hog when sent to market is at the required market weight. FYcess weight is generally achieved in excess fat which is undesirable for today's health conscious marketing. FYcess weight is achieved using increased food supply and increased production time both of which are inefficient and lead to financial losses. Marketing a pig that is underweight ofcourse leads to financial penalties.
It is important therefore to have a system for detecting those animals which have achieved the required market weight and to ensure that the detection occurs very shortly after the market weight is achieved.
At the present time it is difficult to detect the time that the hog reaches the required market weight and often this is done simply on the basis of age of the pig regardless of the actual weight that the pig has achieved.
SUMMARY OF THE INVENTION
It is one object of the present invention, therefore, to provide an apparatus and method for selecting and separating those pigs from a group of pigs which have achieved the required market weight.
According to one aspect of the invention there is provided a method for selecting and separating those pigs from a group of pigs which have achieved a required market weight comprising providing a pen having two parallel pen sides arranged to confine a pig therebetween, a first open end and a second open end, spacing the two sides and the two ends so as to receive within the pen only one pig at a time from the group of pigs with that pig 2 2163~93 -standing longitudinally of the pen between the sides with its nose at the first end and its tail at the second end, providin~ at each of said first and second ends a gate which can be opened to allow entry into the pen and exit from the pen by the pig and can be closed to confine the pig within the pen, providing 5 at the first end supply means for providing a consumable product to the pig inthe pen, providing means for detecting the weight of said one pig while in the pen, initially maintaining the gate at the first end closed while the gate at the second end is maintained open to allow said one pig to enter the pen, detecting the weight of the pig standing in the pen, in response to the weight 10 being less than said required market weight maintaining said gate at the first end closed and the gate at the second end open so that the pig is caused to exit by backing up through the gate at the second end, in response to the weight exceeding said required market weight closing the gate at the first end and opening the gate at the second end so that said one pig is caused to exit 15 from the pen by moving forward through the gate at the first end, and in response to detec~ion of a weight indicating said one pig having left the pen closing the gate at the first end and opening the gate at the second end.
According to a second aspect of the invention there is provided an apparatus for selecting and separating those pigs from a group of pigs 20 which have achieved a required market weight comprising a pen having two parallel pen sides arranged to confine a pig therebetween, an open first end and an open second end, the two sides and the two ends being spaced so as to receive within the pen only one pig at a time from the group of pigs with that pig standing longitudinally of the pen between the sides with its nose at 25 the first end and its tail at the second end, a gate at each of said first and second ends which can be opened to allow entry into the pen and exit from the pen by the pig and can be closed to confine the pig within the pen, supply means at the first end for providing a consumable product to the pig in the pen, weighing means including a floor panel of the pen for detecting the weight of said one pig, and control means responsive to the weight of the pig for controlling opening and closing of the gates.
One embodiment of the invention will now be described in conjunction with the accompanying drawings in which:
BRIEF DESCRIPTION OF THE DRAWINGS
Figure 1 is an isometric view of a pen for use in selecting and separating pigs according to the present invention.
Figure 2 is a longitudinal cross sectional view through the pen generally as shown in Figure 1 but including a number of minor modifications.
Figure 3 is a top plan view of the pen insitu in a hog production facility.
Figure 4 is a transverse cross-sectional view of a modified embodiment of the pen of Figure 1.
Figure 5 is a longitudinal cross-sectional view of the pen of Figure 4.
In the drawings like characters of reference indicate corresponding parts in the different figures.
DETAILED DESCRIPTION
A penning system for hogs in an intensive hog farming production facility is shown schematically in plan view in Figure 3 and includes a divider wall 10 separating a holding pen 11 from a raising pen 12. The pen 12 is intended to house a number of pigs in the growing stage up to the required market weight which can vary in accordance with market requirements and with the breed of animal. The pen 12 is intended as a raising or living pen for the animals and includes feeding systems (not shown), suitable dividing walls and a water trough generally indicated at 13. The water trough is arranged along the side wall 10 dividing the raising pen 12 from the holding pen 11.

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-The holding pen 11 is intended for housing those pigs which have achieved market weight and thus are ready for the next shipment to the hog killing plant.
The trough 13 comprises simply a flat base 14 with an upstanding 5 front wall 15 and an upstanding rear wall 16 for containing water on the base.The depth of the water is controlled by a float valve system schematically indicated at 17. The trough also has ends 18 and 19. The trough is divided by a number of vertical divider members 20 which extend outwardly from the front of the trough and separate the trough into separate stalls each for 10 receiving a separate pig. The spacing between the divider membe~s 20 is arranged to define stalls 20A and 20B with the latter being wider than the former and arranged at the right hand end of the trough. The stalls 20A are of a narrower width so that the pigs which are some distance from the market weight can readily pass between the divider members 20 into the stalls 20A
15 for accessing the trough. Those pigs which are however at or approaching the market weight are too wide to comfortably reach between the divider members 20 into the stalls 20A to access the water in the trough and hence must enter into the wider stalls 20B.
A separating pen is generally indicated at 21 and is shown in 20 more detail in Fi~ures 1 and 2. The separating pen is arranged at one end 18 of the trough so that that one end just projects into the pen 21 sufficiently toallow the animal in the pen 21 to ~ccess the water in the trough. Those animals that are therefore at or approaching the market weight must enter either the stalls 20B or the pen 21, which is of approximately equal width, to 25 access the water in the trough. The regular drinking which the pig requires therefore causes the larger pigs to regularly enter the pen to become used to it. The stalls 20B are arranged closely adjacent the pen so that the larger animals drink at that end of the trough. The stalls 20B include manually -actuable gates 20C by which they can be closed off when it is required to separate the pigs thus requiring them only to enter the pen for drinking.
The pen 21 comprises two side walls 22 and 23 arranged to confine the animal between the side walls 22 and 23 with the spacing 5 between the side walls sufficient just to receive the width of one pig which is at or adjacent the market weight. The side walls thus prevent more than one pig entering the pen at a time in the side by side orientation. The length of the side walls 22 and 23 is arranged so that a first or discharge end 24 of the pen is spaced from a second or entry/exit end 25 of the pen by a distance just 10 sufficient to receive the single pig with its nose at the first end and its tail at the second end thus inhibiting further pigs from entering the pen behind the single pig allowed into the pen. The first and second ends of the pen are open to allow the pig to enter and leave the pen between the side walls. The first and second ends are closed by a gate 26 at the first end and a second gate 27 15 at the second end. Each of the gates can be raised and lowered in a vertical direction so as to move from a closed position shown in the figures 1 and 2 at the first end of the pen to a raised position shown at the second end of the pen.
Each of the side walls 22 and 23 of the pen comprises a top rail 20 28 and a bottom rail 29 each of which is formed from tubular metal of square cross section with these top and bottom rails being interconnected by elements which prevent the escape of the animal to the side of the pen. In Figure 1 the conne~ling elements between the top and bottom rails are shown as a plurality of vertical bars or rods for example of 1 /2" steel connected 25 between the rails. In the embodiment shown in Figure 2, the sides include an intermediate rail 30 approximately at mid height of the pen with a bottom part of the side being formed by sheet metal 31 and a top part of the side being formed by bars 32 similar to the bars 33 of Figure 1.

-Each of the sides has at its forward and rearward end a vertical channel member. Thus the side 22 has a first channel member 34 and a second channel member 35. The side 23 has a first channel member 36 and a second channel member 37. The channel members 34 and 36 at the front of 5 the pen face inwardly to define a slide guide arrangement for the first gate 26.
The second channel members 35 and 37 similarly face inwardly and define a slide guide arrangement for the second gate 27.
Each of the gates is formed from a top rail 38 and a bottom rail 39. In the embodiment shown in Figure 1, the rails 38 and 39 are 10 interconnected by vertical bars 40 similar to the bars 33. In the embodiment shown in Figure 2, the second gate 27 includes the bars 40 whereas the first gate 26 includes an intermediate transverse rail 42 and a covering layer of sheet metal 43 so that the first gate is fully closed and does not allow viewingby the animal through the gate and thus through the opening in the wall 10 at 15 which the gate is locateJ. This arrangement prevents the animals from loitering in the pen to view happenin~s in the holding pen 11 so that the animal is more inclined to back out of the pen when finished drinking.
In Figure 1 both sides of the pen are constructed with an opening adjacent the first gate for receiving the trough 13. This opening is formed by a20 horizontal bar 44 which is raised from the bottom rail 29 with shorter bars 33A
extending from the horizontal bar 44 to the top rail 28. The horizontal bar 44 is raised above the top edge of the trough so that the animal can access the water in the trough without getting its head stuck and without the necessity for the trou~h to extend across a significant part of the width of the pen. In 25 pra~lice, therefore, the trough will normally extend into the pen by the distance of the order of three inches with the bar 44 raised above the trough by a distance of the order of seven or eight inches.

_ Each of the sides 22 and 23 of the pen are mounted on a base section 50 of the pen which is formed by two channel members 51 and 52 extending along the length of the pen each underneath a respective one of the botlG~Y) rails of the sides. The channel members are interconnected across a 5 bottom of the channel members by a base plate 53 which closes a bottom of the base 50. A skid or runner 54 is located underneath a bottom flange of each of the channel members so as to support the base 50 of the pen upwardly from the ground and to allow ready transportation of the pen. The base supports a floor plate 55 of the pen which is a rectangular plate of rigid 10 sheet metal of sufficient thickness to accommodate the weight of the animal without bending with that plate being pivoted at one end to the upper flanges of the channel members and supported adjacent its opposed end by a load cell schematically indicated at 60. The floor plate thus includes a bolt 61 which passes through the floor plate and engages onto a spacer 62 of the load cell so 15 to apply force downwardly onto the load cell from the floor plate in responseto an animal standing on the floor plate. The floor plate is dimensioned so thatit defines a full floor for the interior of the pen so that all four feet of theanimal rest upon the floor plate and apply weight onto the load cell to determine the weight of the animal. A pivoting arrangement for the floor plate 20 can be used in view of the fact that the animal is located within the pen by the dimensions of the pen so that it reaches a particular position along the length of the floor plate each time it enters the pen. The load cell can thus be calibrated to accommodate the weight of the floor plate itself and to accommodate the position of the animal on the plate and to accurately 25 determine the weight of each animal entering the pen.
The floor plate 55 is thus located at the top of the base and thus is raised from the ground by a distance of the order of six to eight inches. If necess~ry, therefore, a ramp 63 can be provided at the second end of the pen 8 2163~93 to assist the animals in entering the pen without inhibition due to any form of step at the second end of the pen.
The pen includes a control and operation system mounted within a housing 65 on top of the pen mounted on two of a plurality of cross beams 66. The housing contains an electronic control unit 67 and a drive motor 68.
The drive motor 68 includes a sprocket 69 coupling with an elongate chain 70.
The chain passes from the sprocket 69 forwardly of the housing to an idler sprocket 71 adjacent the gate 26 and to a second idler sprocket 75 adjacent the gate 27. The chain 70 p~sses over the sprocket 71 and extends downwardly along the gate 26 to a position adjacent the bottom of the ~ate.
Similarly the chain p~sses over the sprocket 72 and extends to a bottom of the gate 27.
In operation, the pen is mounted in the opening in the wall 10 at the end of the trough 13 and is normally maintained in the position where the first gate is closed and the second gate is open.
As previously stated the animals when they are smaller initially drink at the trough in the stalls 20A between the dividers 20 since this part ofthe trough is much more readily accessible than the portions of trough at the end 18. Only when the animals are approaching the market weight are they inhibited from drinking from the trough in the stalls 20A and thus very quickly learn that they must move to the right hand end of the trough to drink from the compartments 20B or within the pen 21 at the end 18 of the trough. For those few days as the animal approaches the market weight, therefore, the animals regularly enter the pen 21 to carry out the regular ritual of drinking whenever they wish. The number of stalls 20B is selected with the pen to ensure that the animals have sufficient drinking space and yet are required to regularly visit the pen and thus get used to the pen. On the day the producer wishes to ship the animals to market the manual gates 20C on the stalls 20B
are closed so that the animals must only enter the pen for drinking.
At each entry of the animal into the pen 21, the floor plate 55 takes the weight of the animal and its weight is detected by the load cell 60 5 and communicated to the control unit 67.
In the event that the weight of the animal when detected by the load cell 60 is less than the predetermined market weight, the control unit 67 is responsive to this detection and leaves the pen in its initial condition so that the first gate is closed and the second gate remains open. The animal quickly 10 therefore learns that it exits from the pen by backing up between the sides and back down the ramp to the floor of the pen.
In the event that the weight of the animal is equal to or greater than the predetermined market weight, this is detected by the load cell 60 which communicates to the control 67. The control unit is responsive to the 15 overweight deleclion by the cell 60 and is programmed to respond to that overweight detection only if the weight detected remains constant for a predetermined resetable period of time. This detection delay is used to prevent the weight of the front feet of a pig behind the first pig being added to the weight of the pig on the plate and thus giving a false reading. This will 20 normally only occur while the pigs are moving so that the weight will not remain constant for the required period of time. It has been found that the delay waitin~q for the constant weight allows the pen to operate to properly select the pi~s of the required weight since it allows the measurement of the weight of a sinqle pig while that pig is stationary in the act of drinking. A time 25 period of the order of 1.5 seconds is allowed and this time has been found toallow the first or single animal to enter the pen and be properly weighed beforea second pig can place its front feet on the plate thus interfering with the proper weighing of the first pig in the pen.

On detection therefore of the weight of the pig in the pen exceeding the predetermined market weight, the motor 68is actuated to drive the chain 70 to simultaneously lower the second gate 27 and raise the first gate 26. This actuation occurs while the animal is drinking whereupon the 5 animal realizes that it cannot get out of the pen by backing up in its normal way but instead must exit ony by moving forward. The drink trough projects into the pen only by relatively short distances so that it does not interfere with the animal stepping forwardly and passing from the pen into the holding pen 1 1 .
On detection of the animal leaving the pen that is the detection of a zero weight on the plate 55 when the rear feet of the animal leave the pen the control unit 67 immediately operates the motor 69 to reverse the chain drive to reclose the first gate and open the second gate to return to the initial position.
The device of the present invention, therefore, provides a system which is incorporated into the normal daily activity of the animal so that the animal becomes used to the pen and thus can be weighed a number of times each day particularly on shipping day so that those pigs only which have achieved the required market weight are selected and separated from the remainder of the group of animals within the pen 12 and exited into the holding pen 11 for shipment to market. There is less possibility therefore of the animals going overweight which is not desirable for best market value or of the animal being separated prior to achieving market weight.
Turning now again to Figure 2, the control unit 67 includes a 25 visual display 67A and a plurality of manual input buttons 67B. The control unit includes a microprocessor allowing programming of various inputs and controls for the operation of the device. The first one of the manual input buttons therefore selects from a menu of input features which can effect control by the user operating numerical input keys of the following parameters:
a) The selecled market weight for the pig at which the device is actuated to release the pig into the holding pen.
b) The total number of pigs which are to be selected and/or the total weight of pigs to be selected. It will be appreciated that the producer generally has a maximum weight which can be shipped in any one shipment and therefore the control unit can be pro~rammed to allow the passage into the holding pen of only the maximum number or maximum weight of pigs which can be transported in the allowed load.
c) The motion delay during which the weight must remain constant for the device to actuate movement of the gates. It will be noted that this movement delay requires that the measured weight of the pig remain constant within predetermined limits for a period which can be set by the manually actuable buttons to ensure that the weight measured is an accurate weight and is not caused by inertia from the pig entering the device or by more than one pig being in the device at one time.
Turning now to Figures 4 and 5, there is shown a modified arrangement which operates basic311y in the same manner and is basically the same construction as previously described except for the following modifications.
Instead of the device comprising basically a cage with a separate floor with the floor being mounted on a load cell as described in the previous embodiment, in the second embodiment of Figures 4 and 5 the cage is an integral structure with the floor pan and is suspended at the top from an outside frame structure so that the load cells are positioned at the top of the cage or pen. Thus the cage includes a pair of longitudinal side beams 75 and 76 which are interconnected by main crossbeams 77, 78 at respective ends.

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The cage further includes vertical side bars 79 depending from the side rails 75and 76 respectively and horizontal top crossbars 80 extending across the top of the ca~e between the side rails 75 and 76. The bottom end of the side rails 79 are attached to a floor pan 81 in the form of a U-shaped channel member with upstanding sides 82 and 83 and a horizontal floor plate 84. The side walls 82 and 83 include a top flange to which the vertical side bars 79 are attached. Along a center line of the floor plate 84 is provided a vertically extending flange 85 with a top bar 86 along the top of the flange. The is acts as an "anti-snooze" bar which prevents the pigs from Iying in the pen. There is a tendency for the pigs to lie down in the pen as it is close to the water and is comfortable away from the attentions of other pigs and it is necessary therefore to prevent the pigs from Iying in the pen which will of course preventaccess by other pigs. The vertical bar thus extending longitudinally of the pen prevents the animals from Iying down and yet allows them to walk into the pen with two feet on either side of the vertical bar.
The outer frame supporting the inner cage comprised of generally rectangular frame with four posts 87 defining a front frame section, a rear frame section and two side frame sections. The front and rear frames include three horizontal rails 88, 89 and 90. The side frames include top and bottom rails 91 and 92. One side frame is covered by a solid panel 93 of plastics material closing off that side of the pen from access by or viewing by the animal. The other side of the outer frame is open allowing access to the inner cage and particularly the inner cage has an opening for receiving the water trough as previously described.
The inner cage is mounted on a pair of load cells 95 which are positioned between suitable elements of the cage and the outer frame. In the example shown the load cell 95 is positioned underneath the crossbar 77 and on top of a short support bar 96 projecting inwardly toward the cage from the end rail 89.
The arrangement of Figures 4 and 5 is further modified by the addition of a guard 97 which is mounted on the outer frame at one end post 5 87 and guarding one side of the entry end of the cage. The guard thus projects longitudinally outwardly from the end frame and prevents pigs from knocking into the pig which is wishing to back out of the pen. Pigs have a relatively high level of aggression and the pig wishing to back out of the pen is in a somewhat vulnerable position and hence requires some protection on one 10 side so that it can turn toward the opposite side of the pen as it backs out thus protecting its rear from other animals. The guard comprises a pair of vertical rails 98 and 99 supported at the top and bottom by horizontal rails.
The arrangement of Figures 4 and 5 is yet further modified by a protective L-shaped cover plate 100 which has a horizontal flange 101 and a 15 vertical flange 102 engaging over and covering the end rail 90. The inner edge of the horizontal flange 101 abuts the end edge of the floor plate 84 and thus assists in preventing the penetration of manure and other materials into the area under the floor plate. However since this accumulation of materials in this environment can not be eradicated, the cover plate 100 is mounted on a 20 pair of side rails 103 which allow the cover plate to slide upwardly from itsposition covering the rail 90 to a raised position allowing access to the underside of the floor plate 84 for cleaning and washing of the floor plate and the underfloor area. Prior for convenience of illustration the gates are omittedfrom the arrangement of Figures 4 and 5 although of course these are essential 25 to the operation of the device and therefore are provided mounted on the outer frame as previously described.
Since various modifications can be made in my invention as herein above described, and many apparently widely different embodiments of same made within the spirit and scope of the claims without departing from such spirit and scope, it is intended that all matter contained in the accompanying speciricalion shall be interpreted as illustrative only and not in a limiting sense.

Claims (10)

1. A method for selecting and separating those pigs from a group of pigs which have achieved a required market weight comprising providing a pen having two parallel pen sides arranged to confine a pig therebetween, a first open end and a second open end, spacing the two sides and the two ends so as to receive within the pen only one pig at a time from the group of pigs with that pig standing longitudinally of the pen between the sides with its nose at the first end and its tail at the second end, providing at each of said first and second ends a gate which can be opened to allow entry into the pen and exit from the pen by the pig and can be closed to confine the pig within the pen, providing at the first end supply means for providing a consumable product to the pig in the pen, providing means for detecting the weight of said one pig while in the pen, initially maintaining the gate at the first end closed while the gate at the second end is maintained open to allow said one pig to enter the pen, detecting the weight of the pig standing in the pen, in response to the weight being less than said required market weight maintaining said gate at the first end closed and the gate at the second end open so that the pig is caused to exit by backing up through the gate at the second end, in response to the weight exceeding said required market weight closing the gate at the first end and opening the gate at the second end so that said one pig is caused to exit from the pen by moving forward through the gate at the first end, and in response to detection of a weight indicating said one pig having left the pen closing the gate at the first end and opening the gate at the second end.

2. The method according to Claim 1 including moving the gates vertically upwardly.

3. The method according to Claim 1 including moving the gates simultaneously.

4. The method according to Claim 1 wherein the weight of the pig is detected by supporting the pig on a substantially rigid floor plate and suspending the floor plate on a load cell such that downward force from the rigid floor plate is applied onto the load cell.

5. The method according to Claim 1 wherein the supply means for consumable product comprises a water trough.

6. The method according to Claim 5 wherein the water trough projects through one side of the pen so as to form a portion of the water trough adjacent the first end of the pen.

7. The method according to Claim 6 wherein the water trough comprises an elongate water trough and wherein there is provided a plurality of divider members dividing access to the water trough to a number of pigs arranged side by side along a length of the water trough, the pen being arranged at one end of the water trough, some of the divider members being arranged such that those pigs which have achieved or are close to achieving the required market weight are too large to reach the water trough at those divider members.

8. The method according to Claim 7 including providing some of the divider members to define access to the trough which is substantially equal in dimension to that of the pen and providing means for closing off access to the trough at said divider members when it is required to weigh the pigs.

9. The method according to Claim 1 wherein the pen is arranged such that the first end communicates with a holding pen for those pigs having achieved the required market weight and wherein the gate at the first end is formed of a sheet material preventing viewing of the holding pen bythe pig within the pen.

10. The method according to Claim 1 including controlling the closing of the gate at the second end and opening of the gate at the first end such that these actions are effected only if the weight detected exceeds said required market weight and is maintained constant for a predetermined period of time.
12. The method according to Claim 1 including providing means for preventing the pig from lying down in the pen.
13. The method according to Claim 1 including providing a guard rail on one side of the pen at said second end projecting outwardly from the pen longitudinally thereof.
14. The method according to Claim 1 including providing control means having manually actuable input means and inputting into the control means the required market weight and a total number of pigs to be separated.
15. Apparatus for selecting and separating those pigs from a group of pigs which have achieved a required market weight comprising a pen having two parallel pen sides arranged to confine a pig therebetween, an open first end and an open second end, the two sides and the two ends being spaced so as to receive within the pen only one pig at a time from the group of pigs with that pig standing longitudinally of the pen between the sides with itsnose at the first end and its tail at the second end, a gate at each of said first and second ends which can be opened to allow entry into the pen and exit from the pen by the pig and can be closed to confine the pig within the pen, supply means at the first end for providing a consumable product to the pig in the pen, weighing means including a floor panel of the pen for detecting the weight of said one pig, and control means responsive to the weight of the pig for controlling opening and closing of the gates.

16. The apparatus according to Claim 15 including means for moving the gates vertically upwardly.
17. The apparatus according to Claim 15 wherein the control means is arranged for moving the gates simultaneously.
18. The apparatus according to Claim 15 wherein the supply means comprises a water trough.
19. The apparatus according to Claim 15 wherein the control means is arranged to effect controlling the closing of the gate at the second end and opening of the gate at the first end such that these actions are effected only if the weight detected exceeds said required market weight and is maintained constant for a predetermined period of time.
20. The apparatus according to Claim 15 including means for preventing the pig from lying down in the pen.