Abstract:
A feeding stall for an animal that allows a gestating sow or other animal to enter the stall for feeding, in which movement of the sow triggers automatic closure of a gate assembly, without manual intervention from the farmer. This protects the sow from other sows when it is feeding. When the sow has finished feeding, it can readily exit the stall, opening the entrance gate without manual intervention. Opening and closing of the gate is actuated when the sow urges the gate assembly open or closed. The sow need provide only an initial impulse against the gate, with the remainder of the rotation being provided by a biasing member which urges the gate into the fully open or closed position after being tilted past a neutral position.

Description:
FIELD OF THE INVENTION 
       [0001]    The present invention relates to agricultural equipment for animal husbandry, in particular a feeding stall which has particular application for gestating sows in group pen environments. 
       BACKGROUND 
       [0002]    Gestation stalls are used in swine husbandry as means to protect sows from each other when feeding. Fighting amongst sows and “bullying” by a dominant sow are common behaviour patterns. Stalls for isolating animals are also useful for other agricultural and animal husbandry applications. It is preferable to isolate sows when feeding while leaving them free to mingle with other sows at other times in a group pen. 
         [0003]    A typical gestation stall is an enclosure with an entrance gate at one end for a sow or other animal to enter to feed from a feeding trough located at the opposed end. The entrance gate may be connected to the stall body via an arrangement of linkages that are spring loaded to keep the gate open and which closes after a sow enters the stall. After the sow has eaten, the gate can reopened for the sow to exit. The sow (or other animal) is typically unable to actuate the gate by itself to enter and exit on demand. Instead, manual operation of the gate by an operator may be required to open and close the gate. This type of system is not practical where the stall is located within a group pen and the feeding stall is frequently accessed by sows as they utilize the stall for feeding. As well, the complexity of existing systems can result in jamming and breakdown. 
       SUMMARY OF THE INVENTION 
       [0004]    The present invention relates to a stall for an animal in which the gate may be actuated by the animal without the need for human intervention, which has particular application for isolating gestating sows for individual feeding within a group pen environment. The gate is associated with a gate assembly which can be opened or closed from the interior of the stall by the animal contacting a component of the stall which when contacted actuates the gate to open or close, using the force applied by the animal to actuate the gate. The stall includes a gate assembly which is retained in either of the open or closed position but to either admit an animal or isolate an animal within stall, and which can then be displaced between these positions by an animal located within the stall but not by an animal located outside the stall. 
         [0005]    According to one aspect, the invention relates to a stall for an animal comprising an enclosure having a rearward end defined by an opening for the animal, an opposed forward end and a gate assembly. The gate assembly comprises in a broad aspect a gate portion moveable between open and closed positions for selectively blocking said open end, a lever member connected to the gate for urging the gate closed when contacted by an animal entering the enclosure and a biasing member connected to said lever member for urging the gate assembly into the open or closed positions. The biasing member is configured to urge the gate assembly towards the closed position when the gate assembly is provided with an initial impulse towards the closed position past a neutral balanced position and to urge the gate towards the open position when the gate assembly is provided with an initial impulse towards the open position past the neutral position. 
         [0006]    The biasing member may comprise a fixed member engaged to the gate assembly and a moveable component that is displaceable along said fixed member. In this aspect, tilting of the biasing member forwardly past the neutral position displaces the moveable component forwardly wherein gravity acts on the biasing member to urge the gate open and tilting of said biasing member rearwardly past the neutral position displaces the moveable component rearwardly wherein gravity acts on the biasing member to urge the gate closed. 
         [0007]    The fixed member may consist of a container having opposed ends such that the moveable component is enclosed within said container. The moveable component may consist of a flowable substance such as water or other liquid-containing substance. 
         [0008]    The fixed member of the biasing member may span a balance point of said gate assembly, which can be defined by a pivot mount that secures the lever member to the enclosure. The fixed member may incline downwardly and rearwardly when said gate is closed, for example at an angle of about 10 to 15° from the horizontal. The lever member may be configured to decline downwardly into the interior of said stall when the gate is open for contact with said animal upon entering said stall and to rotate upwardly to form a top of said stall when said gate is closed. 
         [0009]    According to another aspect the stall includes a first latch to latch said gate in the closed position. The latch comprises a latch body rotatable between a latched position for engaging the enclosure and an unlatched position wherein the latch body is configured for contact with the animal within the enclosure for unlatching upon contact with an animal from the interior of said enclosure. The latch body may comprise an arm rotatably engaged to said gate assembly having an upper end for contacting said enclosure. According to this aspect, rotation of said arm in a first direction engages said arm with the enclosure to latch said gate assembly in a closed position and the arm is configured for contact with an animal within said enclosure during exit therefrom whereby such contact rotates the arm into a disengagement position to unlatch said gate assembly. 
         [0010]    The stall may further include a second latch for securing the gate assembly in a closed position. The second latch may comprise a latch keeper on the exterior of the stall for actuation of the latch by an operator from the exterior of the stall. The second latch may further include a latch body moveable by said latch keeper between a first position configured to engage said gate assembly upon closure of said gate and a second position wherein said latch body is disengaged from said gate assembly. 
         [0011]    According to a further aspect, the stall may further include a feed dispensing assembly comprising a hopper, a feed metering unit and a discharge chute. The feed metering unit may be configured to release a selected quantity and/or mixture of feed from said hopper to said chute in response to an electronic signal from a central electronic processing unit (CPU). 
         [0012]    According to a further aspect, the invention relates to a gate assembly for an animal feeding stall which comprises an enclosure having a rearward end defined by an opening for the animal, an opposed forward end. The gate assembly comprises a gate moveable between open and closed positions for selectively blocking said open end, a lever member connected to the gate for urging the gate closed when contacted by an animal entering the enclosure and a biasing member connected to said lever member for urging the gate assembly into the open or closed positions. The biasing member is configured to urge the gate assembly towards the closed position when the gate assembly is provided with an initial impulse towards the closed position past a neutral balanced position and to urge the gate towards the open position when the gate assembly is provided with an initial impulse towards the open position past the neutral position. 
         [0013]    The biasing member and lever member of the gate assembly may optionally be as recited above. 
         [0014]    The gate assembly may be further comprise a pivot mount for mounting the gate assembly to the enclosure and pivoting the gate assembly about a horizontal axis whereby the horizontal axis defines a balance point of said gate and the lever member extends forwardly of said pivot mount and angles downwardly into said stall when closed. 
         [0015]    According to the present invention, during normal operation the gate may be automatically mechanically closed by an animal entering the enclosure and exerting a force against a lever member within the enclosure (which is positioned to obstruct the animal&#39;s normal movemento) and subsequently opened by the animal from within the enclosure without any manual intervention by the farmer, solely by forces exerted by the animal during its normal movement into and out of the stall. In addition, because of its simplicity, this invention requires less maintenance than at least some other stall systems known to the art, thus reducing the overall maintenance cost of a barn. 
         [0016]    Further aspects of the invention are explained with the aid of drawings and a detailed description which describe certain non-limiting embodiments of the invention. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0017]      FIG. 1  is a perspective view of a stall with the gate in a closed position according to a first embodiment of invention. 
           [0018]      FIG. 2  is a perspective view as in  FIG. 1  showing the gate in the open position. 
           [0019]      FIG. 3  is an exploded perspective view of the first embodiment, in the closed position, seen from the rear thereof. 
           [0020]      FIG. 4  is an enlarged perspective view of a portion of the stall, indicated by “A” in  FIG. 3   
           [0021]      FIG. 5  is an exploded perspective view of the first embodiment in the closed position, from the front thereof. 
           [0022]      FIG. 6  is an enlarged perspective view of the portion shown in “B” of  FIG. 5 . 
           [0023]      FIG. 7  is a further perspective view of the first embodiment showing an optional anti lie-down bar and feeder assembly. 
           [0024]      FIG. 8  is a front elevational view thereof. 
           [0025]      FIG. 9  is a top view thereof. 
           [0026]      FIG. 10  is a side view thereof. 
           [0027]      FIGS. 11 and 12  are schematic views, in side elevation, of the gate assembly in the open and closed positions respectively. 
           [0028]      FIG. 13  is a perspective view showing the second latch assembly of the stall, in the latch engagement position. 
           [0029]      FIG. 14  is a further perspective view showing the second latch assembly, in the latch disengagement position. 
           [0030]      FIG. 15  is a further perspective view showing an enlarged view of a portion of the second latch assembly, showing the latch in an engagement position. 
           [0031]      FIG. 16  is a perspective view showing an enlarged view of the second latch assembly in the latch engagement position. 
           [0032]      FIG. 17  is a perspective view of a second embodiment wherein the feeder comprises dual feed hoppers. 
           [0033]      FIG. 18  is a perspective view of a fourth embodiment of the invention comprising quadruple stalls. 
           [0034]      FIG. 19  is a perspective view of a third embodiment of the invention comprising dual stalls. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    Referring initially to  FIGS. 1-10 , a feeding stall  100  according to the invention is shown. Feeding stall  100  can be used for feeding hogs, in particular gestating sows, to permit the animals to feed undisturbed by other animals. Stall  100  has particular application in a group pen environment in which it is desirable to isolate sows during feeding. As well, it will be seen that the invention may be adapted for use by other animals. Feeding stall  100  is intended for use in a facility such as a barn having a generally flat floor  102 . Stall  100  comprises an open-framed enclosure  10  defined by opposing vertical sidewalls  104  composed of metal bars  106 , a front end wall  108 , a substantially open top  112  and an open rear end  115  for animal entry/exit. Rear end  115  is selectively blocked by a gate  200  as described below which is rotatably engaged to the enclosure  10 . Top  112  is closable by a gate assembly  200 , described below. 
         [0036]    The spacing of bars  106  of sidewalls  104  may vary depending on the expected animal size and other factors that may dictate the need for smaller or larger spacing. The bottom of stall  100  can be open to floor  102 . Frame  100  is supported by legs  114  which rest on feet  116  that may optionally be bolted or otherwise fastened to floor  102 . The various frame members that make up enclosure  10  may be fabricated from steel rods, bars and/or plates, or other suitable frame members that can be fabricated into enclosure  100  by being welded, bolted or otherwise fastened together to form a rigid and robust structure consisting of a generally open framework 
         [0037]    A sow anti-lie down bar  118 , shown in  FIGS. 7 and 10 , may be installed within stall  100  to prevent sows from lying down within the stall, thereby expediting the feeding process. Bar  118  comprises a horizontal member  120  elevated from the ground by legs  122 , which may be bolted to the floor. Bar  118  may optionally be secured to a sidewall  104  of stall  100 . 
         [0038]    Stall  100  further comprises a gate assembly  200 , shown in isolation in  FIGS. 11 and 12 , which is operable by a sow to isolate itself within the stall. Gate assembly  200  comprises parallel, spaced apart frame members  202  which are generally L-shaped. Gate assembly  200  can pivot upwardly upon actuation by a sow from within the enclosure to open the gate or downwardly to close the gate. A first end of frame members angles downwardly and forms a gate  210  opposed to end wall  108 . Gate  210  is defined by downwardly-angled segments  203  of frame members  202 , an upper cross bar  204  which spans segments  203 , a pair of lower cross bars  207   a  and  207   b  which extend horizontally towards each from a lower portion of segments  203 , a pair of spaced apart vertical bars  205   a  and  205   b  which extend between respective lower cross bars  206  and upper cross bar  204  and a pivoting latch actuator panel  260 . Panel  260  has a central oval opening  206  which is configured for performing procedures on sows as they feed. Frame members  202  also include a generally horizontal (when the gate is closed) segment that merges with gate  210  and which defines a lever member  212 . Gate assembly  200  is pivotally mounted to sidewalls  104  at lever member  212 . Lever member  212  is further defined by an array of cross bars  214  that span frame members  202 . Lever member  212  covers the top of stall  100  when gate assembly  200  is closed, as seen in  FIG. 1 . The open position of gate assembly  200  is shown in  FIG. 2  and in this position, lever member  212  is inclined downwardly and forwardly to a position that fully or partially blocks the interior of stall  100  to block access of the sow to the feed located on the other side of lever member  212 . As described below, in order to reach the feed, the sow is required to contact lever member  212  as she moves towards the feed and thereby urges it upwardly out of the way. This action causes lever member  212  to rotate upwardly, thereby lowering gate  210  and closing the stall. 
         [0039]    Gate  210  is angled rearwardly and downwardly when closed. As a result of the rearward slope, when the sow within stall  100  backs away from the feeding area (for example, when the sow has finished feeding and wishes to exit stall  100 ), rearward pressure exerted against gate  210  is translated into a vertical force acting on gate assembly  210  which causes gate assembly  200  to rotate upwardly. As described below, this initiates opening of the gate to allow the sow to depart, which also lowers lever member  212  for the next sow to contact upon entry into stall  100 . 
         [0040]    Gate assembly  200  is hinged to sidewalls  104  by a pivot bar  209  that spans and extends past frame members  202 . Pivot bar  209 , seen in detail in the exploded views shown in  FIGS. 3 and 5 , comprises a transverse member fastened to frame members  202  that defines a horizontal axis of rotation of gate assembly  200 . The respective ends of pivot bar  209  are attached to downwardly-extending arms  214 , which in turn are each pivotally mounted to a corresponding sidewall  104  by a mount plate  215  by pivot bolts, bushings or other pivotal attachment means. 
         [0041]    Pivot bar  207  is located relative to gate assembly  200  at or close to the center of gravity or balance point  250  of gate assembly  200 . As a result, gate assembly  200  is balanced on pivot bar  207  and minimal effort is required to rotate gate assembly  200  in either direction about pivot bar  207 . Gate assembly  200  is rotatable between the closed position of  FIG. 1  and the open position of  FIG. 2 . The open position seen in  FIG. 2  is defined by contact of the forward end of lever member  212  with the ground. The closed position seen in  FIG. 2  is defined by contact between lever member  212  and a transverse bar  120  extending between sidewalls  104  adjacent to open rear end  115 . In this position, gate assembly  200  rests on bar  120 . In the closed position of  FIG. 1 , gate  210  blocks the opening  115  of stall  100 . When rotated into the open position of  FIG. 2 , gate  210  is clear of opening  115  of stall  100  to permit entry or exit of an animal. In this position, lever member  212  angles downwardly into the interior of stall  100  where it may be contacted by an animal entering stall  100  as described below. 
         [0042]    Rotation of gate assembly  200  is facilitated by a biasing member  1  mounted to gate assembly  200 , seen in detail in  FIGS. 11 and 12 . Biasing member  1  urges gate assembly  200  towards the closed position when the gate is tilted past the balanced or neutral position towards the closed position and also urges gate assembly  200  towards the open position when the gate is tilted past the balance position towards the open position. When gate assembly  200  is precisely at its balance or neutral position, biasing member does not exert a force in either rotational direction on gate assembly  200 . In the present embodiment, biasing member  1  achieves this result by shifting its center of gravity as it is tilted in one direction or the other. This is accomplished by providing an elongate member with a moveable center of gravity wherein when biasing member is horizontal it is in a neutral, balanced position and when tilted in one direction or the other along a horizontal axis which is transverse to the elongate (front to rear) axis of stall  100 , it applies a downward force towards one end or the other. In the present embodiment, biasing member  1  comprises a hollow plastic tube  240  having sealed ends  242  within which a free-flowing substance  244  such as water or other fluid or sand is retained to shift its center of gravity as the biasing member is tilted. It will be seen that any substance or article may be incorporated into the biasing member that can move from one end of the member to the other, such as any flowable substance trapped within tube  240 . Biasing member  1  may comprise in general terms a combination of a fixed member and a moveable component that can travel along the fixed member towards respective forward and rearward ends thereof to shift the center of gravity sufficiently to overcome anti-rotational forces acting on gate assembly  200 , such as frictional forces, inertia, slight shifts in weight brought on by accumulation of debris and others. The moveable component may comprise any object(s) or substance that can be displaced along the fixed member by tilting thereof along a horizontal transverse axis. 
         [0043]    Biasing member  1  is mounted to gate assembly  200  at an angle whereby when lever member  212  is horizontal, biasing member  1  declines downwardly and rearwardly. For this purpose, biasing member  1  is connected at its rearward end directly to crossbar  204  of lever member  212  adjacent to gate  210 . The forward end of biasing member  1  is connected to lever member  212  via a post  151  which elevates the forward end thereof relative to its rearward end. Biasing member  1  thus inclines downwardly towards the rear of stall  100  when the gate assembly  200  is closed, for example by an angle of between 10 and 15°. 
         [0044]    Biasing member  1  is centered over balance point  250  of the gate assembly  200  whereby biasing member may apply a substantially similar downward force acting in either direction of rotation of gate assembly  200 , as the center of gravity of biasing member  1  is shifted forwardly or rearwardly of balance point  250 . Due to the downward tilt of biasing member  1  when lever member  212  is horizontal, biasing member  1  exerts a downward force rearwardly of balance point  250  when gate assembly  200  is closed, thereby urging it towards the closed position. When gate assembly is rotated towards the open position, for example when a sow exerts a rearward force on gate  210 , as soon as biasing member is rotated past the horizontal (balanced) position, it will start to exert a downward force on gate assembly  200  forwardly of balance point  250  thereby urging the gate towards the open position. It will thus be seen that a relatively slight nudge of the gate towards the open position, sufficient to elevate the gate past the balanced position of biasing member  1 , will cause biasing member to urge the gate into the fully open position. The reverse sequence will occur on closing of the gate, when a sow enters into stall  100  and contacts the downwardly-angled portion of lever arm  212  located within the stall, urging it upwardly past the neutral position. 
         [0045]    Biasing member  1  provides an overcenter-type action to selectively urge gate assembly  200  into either one of the open or closed position when gate assembly  200  is given an initial impulse towards either position past the balance point  250 , and to retain it in the open or closed position until a sufficient countervailing force is applied which urges gate assembly  200  past the balance point  250  in the opposing direction. In this fashion, biasing member  1  serves to swing the gate into either one of the fully open or fully closed position when given an initial nudge by an animal either entering or exiting the stall. This fully opens the gate out of the way of the animal after the initial nudge towards the open position and fully closes the gate automatically once the animal has given an initial nudge in this direction as it approaches its food. As well, biasing member  1  serves to retain the gate in one of the open or closed position by the weight of gravity acting on balancing member  1 , as its center of gravity shifts rearwardly and forwardly respectively. 
         [0046]    Biasing member  1  may be opened to permit the flowable material to be added or removed if required. Biasing member  1  is partially filled with water  244  (shown in dotted lines in  FIGS. 10 and 11 ). The amount of water inside biasing member  1  is typically about ⅓ of the total volume of the tube, although it will be seen that this amount may vary. 
         [0047]    At the start of the sow feeding cycle, gate  200  is in the open position of  FIG. 2 , in which lever member  212  slopes downwardly and forwardly wherein its front edge contacts floor  102  adjacent to front end wall  108 . Gate assembly  200  is retained in the open position by biasing member  1 ; at this stage the center of gravity of biasing member  1  is located forwardly of balance point  250  of gate  200  urging gate assembly  210  towards the open position. Animal feed is normally deposited at the front of stall  100  adjacent end wall  108 , for example in a feed trough or deposited on the floor. In most cases, the feed will be deposited after the sow has entered the stall and its identity is confirmed. The sow enters the stall and walks to its front end as result having learned to expect feed to be deposited at that location, which is forwardly of lever member  212  when this is in the open position. As a result, lever member  212  effectively blocks the animal from reaching the location where food is normally deposited. This encourages the animal to contact lever member  212  to push it aside in order to reach the food location. As the sow enters the stall and walks towards the feed location, its head, shoulder or other body part pushes forwardly against lever member  212  as the sow urges itself against lever member  212 . This action urges lever member  212  upwardly as it rotates the gate assembly towards the “closed” position. As this occurs, the water within biasing member  1  flows rearwardly, thereby shifting its center of gravity rearwardly until it reaches the neutral position and then the “overcenter” position where its center of gravity is located rearwardly of balance point  250 . At this point, gate assembly  200  will continue rotating due to the rearwardly-located center of gravity urging it closed, until it reaches the fully closed position of  FIG. 1 . 
         [0048]    Once gate assembly  200  is closed, a first latch assembly  3 , described below, will then automatically actuate to prevent other animals outside stall  100  from forcing their way in, until the sow located within the stall actuates the gate assembly from within to open the gate. As well, since gate  210  slopes downwardly and outwardly, it is difficult for an animal outside the stall to force it open, since any direct forward force from outside the stall will tend to force the gate towards the closed position. However, a rearward force from a sow located within the interior of stall  100  will tend to urge gate  210  upwardly to open the gate. 
         [0049]    When an animal within stall  100  wishes to exit stall  100 , it will normally back out of the stall. In doing so, the sow will contact gate  210 . The rearward force of the sow against gate  210  is translated into an upward force acting on gate assembly  200  due to the rearward slope of gate  210 . This urges gate assembly  200  towards the open position. The fluid in the biasing member  1  flows towards the front of stall  100  shifting the center of gravity of biasing member  1  forwardly past the neutral position, such that gate assembly  200  is urged into the fully open position by biasing member  1 . After the sow has urged the gate past the neutral position, no further force by the sow is required to fully open gate assembly  200 . Furthermore, it will be seen than no intervention beyond the movement of the animal is needed to open or close the gate. 
         [0050]    As seen in detail in  FIG. 6 , a first latch  3  may optionally be provided to secure gate  200  in the closed position. First latch  3  comprises a panel-shaped latch actuator  260  which is rotatably secured at its lower end to lower cross-bars  207   a  and  b  of gate  200 , which are co-axially aligned. Actuator  260  comprises spaced apart sidewalls  262   a  and  262   b  spanned by a panel  264 . Panel  264  has an oval opening  206  therein to provide access to the sow when the sow is facing away from gate  210  as she feeds for insemination or other procedures. Sidewalls  262   a  and  b  each have an opening for insertion therein of a corresponding one of cross-bars  207  whereby actuator  260  may rotate on co-axial bars  207   a  and  b  about a horizontal axis defined by the common axis of bars  207   a  and  b . The upper ends of sidewalls  262   a  project upwardly of plate  264  and have cutaway regions  268 . Cutaways  268  form cradles for contacting crossbar  120  that spans sidewalls  104  and which is fixedly mounted thereto. When gate assembly  200  is closed, latch  3  is engaged; this is actuated by the forward and upward tilt of gate  210  causing latch actuator  260  to rotate forwardly until cradles  268  engage crossbar  120  and rest against this member. When thus engaged, upward movement of gate assembly  200  is prevented by contact between the cradles  268  and enclosure crossbar  120 . Latch  3  is disengaged by urging latch actuator  260  rearwardly, which can be actuated by a sow contacting actuator  260  as she moves rearwardly seeking to exit stall  100 . This rotates actuator  260  rearwardly, disengaging cradles  268  from crossbar  120 . At this point, latch  3  is disengaged and continued rearward force against actuator  260  causes gate assembly  200  to rotate upwardly into the open position. 
         [0051]    As seen in  FIG. 7 , rotational movement of latch actuator  260  is confined in one direction by the upper gate crossbar  204  that spans frame members  202 , and in a second direction by contact with cross bar  120 . For this purpose, the respective bars  204  and  120  are spaced apart horizontally by a spacing that is sufficient to permit actuator  260  to travel in an arc that allows engagement and disengagement between cradles  268  and bar  120 . Latch actuator can freely rotate in an arc defined by the horizontal space between these respective cross members. 
         [0052]    Stall  100  is provided with a second latch  5 , seen in FIGS.  4  and  13 - 16 , which is configured to secure stall  100  in a closed position. Latch  5  is operable solely from the outside of stall  100  to permit a farmer to secure gate assembly  210  in a closed position that cannot be opened by an animal, for example to perform an examination or other procedure on a sow while confined with the stall. Latch  5  comprises a latch body  290  rigidly secured to a rotatable crossbar  292  whereby rotation of crossbar  292  causes latch body  290  to rotate. Crossbar  292  is rotatably engaged within hubs  294  mounted to opposing sides of stall  100 , whereby latch body  290  rotates upon rotation of crossbar  292 . A handle  296  is engaged to crossbar  292  and comprises a bar that may be slideably engaged within opening  298  that extends through crossbar  292  adjacent an end thereof. Handle  296  permits a user to apply torque to crossbar  292  to easily actuate latch  5 . Handle  296  slides within opening  298  in crossbar  292  to permit handle  296  to selectively engage a latch retainer  300 . 
         [0053]    Retainer  300  comprises a plate  302  welded to the exterior of stall  100  and projecting horizontally outwardly therefrom. Plate  302  has first and second openings  304  and  306  configured to receive handle  296  therein, defining latch and unlatched positions respectively. First opening  304  is positioned to retain the handle in a closed (engagement) position wherein gate assembly  200  may be automatically latched when closed and second opening  306  is positioned to retain handle  296  in an open (disengaged) position wherein gate assembly  210  is maintained in an unlatched position. Handle  296  may be selectively inserted in one or the other of openings  304  and  306 . 
         [0054]    Latch body  290  comprises a base  310  which is fixedly mounted at a proximal end to crossbar  292  and a flipper  312  which is pivotally mounted to a distal end of base  310 . Flipper  312  is configured to fold into base  310  wherein flipper  312  fits at least partially within the interior of base  310 , and to unfold into an extended, engagement position as seen in  FIG. 13  wherein flipper  312  is at a 90 degree angle to the elongate axis of base  310 . Flipper  312  is prevented from rotating past 90 degrees by a stop member, not shown. Flipper  312  is configured to engage forward crossbar  205  of gate assembly  200  when unfolded, to prevent gate assembly  200  from downward movement. 
         [0055]    In normal operation of stall  100 , latch  5  is secured in an open position, as seen in  FIG. 14 . In this position, latch  5  is rotated out of engagement with crossbar  205  of gate assembly  200  into a non-engagement position where it is inoperative for engaging the gate assembly. Handle  296  is inserted within opening  306  to maintain latch  5  in the inoperative (disengaged) position. In this position, gate  200  may be freely opened and closed by an animal entering and exiting stall  100 . If it is desired to secure gate  200  in a closed position, for example to hold an animal securely within stall or  100  or to prevent animals from entering stall  100 , handle  296  is disengaged from opening  306  by sliding it out of engagement, and inserted into opening  304 . This rotates latch  5  into the operative (engagement) position of  FIGS. 13 ,  15  and  16 . In this position, latch  5  can engage gate  200  when gate is closed. However, latch  5  remains of out engagement with gate  200  until gate  200  is closed, which permits the farmer to leave gate  200  open to receive an animal with latch  5  in the engagement position, wherein gate  200  automatically latches fixedly shut when an animal enters stall  100 . At this time when gate  200  moves into the closed position, crossbar  205  contacts flipper  312  and pushes it upwardly thereby folding flipper  312  into base  310 , to permit crossbar  205  to travel past flipper  312 . Once out of contact with crossbar  205 , flipper  312  unfolds by gravity and returns to the open position wherein it prevents downward travel of crossbar  205  and latches gate in a closed position until unlatched by rotation of handle  296 . 
         [0056]    Feeding stall  100  optionally comprises a feed dispenser  400 . In the embodiment of  FIGS. 7-10 , feed dispenser  400  is an electronic sow feeding unit which comprises a hopper  402 , a feed metering system  404  and a discharge chute  406 . Discharge chute  406  deposits a metered quantity of feed on the ground for access by the sow. The mechanical components of metering system  404  are protected from the sow by a barrier  410 . Metering system  404  is adapted to dispense a selected quantity of feed from hopper  402 . Metering system  404  may comprise an electronic controller, not shown, which engages a feed dispenser to dispense a controlled quantity of feed in response to signals received from the central computer processing unit (“CPU”), not shown. 
         [0057]      FIG. 17  shows a further embodiment of stall  420  wherein a feed dispenser  430  is provided which is similar to feed dispenser  400  but comprises dual hoppers  432  and  434  for separate feed ingredients that may be combined into a single feed stream for consumption by the sow. The ingredients may be combined in different ratios for different sows depending on predetermined criteria and data generated for each sow in the herd. Hoppers  432  and  434  feed into a dual feed metering system  436 , which is similar to metering system  404  but is adapted to combine feed ingredients from dual hoppers  432  and  434 . 
         [0058]    A further embodiment  449  is shown in  FIG. 18  wherein dual feed stalls  450  and  452  are provided in side by side relation, each with a single hopper feed dispenser  400 . It will be seen that one or both stalls may be provided a multi-hopper feed dispenser of the type described herein. Stalls  450  and  452  share a common sidewall  454  that divides the respective stalls. 
         [0059]    A further embodiment is shown in  FIG. 19 , which relates to a quadruple dispenser  480 , comprising four feed stalls  482   a, b, c  and  d . Stalls  482   a  and  b  and  482   c  and  d  are in respective side by side relation, and stalls  482   a  and  b  are in back-to-back relation to stalls  482   c  and  d . Each of stalls  482   a - d  is provided with an independently controlled single hopper feed dispenser  400 . 
         [0060]    The CPU (not shown) maintains a database that can be updated in real time or on a delayed basis of the feed quantities and mixtures of feed and time of day of feed delivered to each sow in the herd by the present system. 
         [0061]    It will be seen that feed dispensers  400  in the embodiments hereof may comprise any combination of single hoppers and multiple hoppers, depending on the application. 
         [0062]    The present invention has been described herein by reference to particular embodiments. However, the scope of the invention should not be limited by the embodiments set forth in the examples, but should be given the broadest interpretation consistent with the description as a whole. The claims are not to be limited to the preferred or exemplified embodiments of the invention.