referring now to the drawings , a bison feeder 10 in accordance with the preferred embodiment of the present invention is illustrated in fig1 and 2 and includes a frame 12 , a controller unit 14 , a feed storage unit 16 , a feed dispensing unit 18 , and a plurality of animal separators 20 which serve to both stabilize the bison feeder 10 once positioned and to limit movement of bison between feeding stations . the frame 12 also includes a tow bar 22 which facilitates portability in moving the bison feeder 10 to a different location . in greater detail , the frame 12 is shown generally in fig1 and 2 and includes a carriage 26 with an axle 24 , the axle 24 being positioned at the rear of the bison feeder 10 and which is rotatably mounted to the frame 12 . the frame is generally welded together of steel box channels into a rectangle which serves to support four uprights 28 preferably of steel , angle iron or other suitable materials and located at the corners thereof . the axle carries a pair of opposed wheels 30 and 32 at the rear of the bison feeder 10 , while the tow bar 22 is located at the front of the frame 12 . the tow bar includes a yoke 34 which is provided with a conventional trailer hitch . the controller unit 14 includes a central processing unit 44 shown schematically in fig6 and 7 and an exemplary unit 44 suitable for use in the present invention is a vc4 - 250 unit manufactured by nedap poiesz of hengelo ( gld ), the netherlands and provided with programmable read only memory ( prom ) chip part number 2802015 version cps3fss from the same source . fig6 illustrates the signal path for operative connection of the feeder 10 , wherein the central processing unit 44 is coupled to a plurality of interrogators 46 through a connection box 54 provided by nedap of holland as part number 9803114 . the number of interrogators 46 used corresponds to the number of feeding sites in the bison feeder 10 . for example , in the present invention , three feed stations 48 , 50 and 52 defining respective feed sites are provided and thus the central processing unit 44 is coupled to three corresponding interrogators 46a , 46b and 46c . an exemplary interrogator for use herein is supplied by nedap poiesz of hengelo ( gld ), holland as part no . 9833153 . the central processing unit 44 is also connected to a printer 53 , such as an epson lq5704 via conventional serial cable . current is supplied to power the operation of the feeder as illustrated schematically in fig7 . outside current , supplied at 120 volts a . c . is provided by conventional utility supply or a remote generator . the current is supplied to the central processing unit 44 through the connection box 54 which , in this instance , converts the current to 24 volts a . c . current is supplied to the interrogators 46 through a current monitoring bridge 56 , such as model 9650580 from nedap which is in turn incorporated in a transformer 58 such as model 9809635 from nedap to step down the current to 24 volt d . c . and 24 volt a . c . the interrogators 46 in turn power the auger drive motors 80 for the medication dispensing auger 66 and the feed dispensing auger 68 , as explained in greater detail below . current to operate the bison feeder 10 may be supplied by conventional 110 volt ac power provided from utility circuits , or in remote operations may be provided by an on - site generator powered by , e . g ., propane tanks . further , as shown in phantom schematically in fig7 it is within the contemplation of this invention that power could also be supplied by roof - mounted solar panels 60 which would be located away from access by the feeding bison . the solar panels 60 would in turn be connected to a battery 62 via battery supplying 24 volt d . c . battery supplying 24 volt d . c . current to the central processing unit 44 through a plug adaptor to convert the voltage to 24 volt a . c ., to the transformer 58 including the bridge 56 therein for delivery to the interrogators 46 and auger drive motors 80 , and to the remaining components such as a printer via a converter 57 to change the 24 volt d . c . to 120 volt a . c . as necessary . for small herds and economical operation , power could be supplied only by batteries , which would be charged or changed periodically as necessary . as shown in fig7 an impeller 150 may be connected to a generator or alternator 152 to provide power from wind for units located on the open range , or a generator or alternator 152 may be a powered by propane supplied from tank 154 or other petroleum fuel source such as gasoline or diesel . for example , a winco model llc - 4500e propane generator 156 may be coupled to a garretson model 650 - 262 voltage converter with a dc powered solenoid and 12 volt battery used to start the generator when available amperage is below 23 amps arid to stop the generator when available amperage is above 28 amps , with a magnetech charger used to maintain battery power . other sources of power may also be provided in appropriate locations . each interrogator 46 is in turn coupled to a feed dispensing unit 18 having separate feed delivery augers for each feed station 48 , 50 and 52 , with only one such connection being shown in fig6 and only one interrogator 46 shown in fig6 for brevity , it being understood that each interrogator 46 is coupled to an antenna , and the auger motor of the feed station . each feed station includes a medication dispensing auger 66 and a feed dispensing auger 68 . auger units found suitable for use as both medication dispensing auger 66 and feed dispensing auger 68 in the present invention include a three - inch dispensing auger provided by nedap as model no . 9837043 . as shown in fig4 and 5 , each medication dispensing auger 66 is separately coupled to a respective medication hopper 70 which is relatively much smaller than the main feed hopper 72 best shown in fig1 and 3 . the medication provided in the medication hopper 70 might include vitamins and minerals , antibiotics , or worming medication well known to veterinarians and those in the bison industry . the medication hopper 70 for each feed station is oriented for gravity feed into its respective medication dispensing auger 66 which , when activated , advances a portion of the medication into a feed chute 74 as illustrated in fig6 . similarly , the main feed hopper 72 is provided for gravity feed through feed opening 76 to the respective feed dispensing auger 68 corresponding to each feed station housed in auger feed box 78 . the main feed hopper 72 utilizes gravity to distribute feed received within the hopper 72 through the feed opening 76 to each feed dispensing auger 68 . each feed dispensing auger 68 and medication dispensing auger 66 includes an auger drive motor 80 and an auger screw 82 connected for rotation with the motor 80 . upon receipt of a signal through the interrogator , the drive motor 80 rotates the auger screw 82 of the feed dispensing auger 68 one turn to dispense a desired portion of the ration into the feed chute 74 . the feed chute 74 is in turn connected to a conduit 84 which may be of synthetic resin or the like and delivers the portion into the feed cup 86 . similarly , the medication dispensing augers 68 deliver medication to the conduit 84 through downspouts 110 . the feed cups are connected to the frame as shown in fig4 by brackets 88 . the frame 12 also carries antenna supports 92 corresponding to each feed station . each l - shaped antenna support 92 is preferably of tubular steel and welded to the lower portion of the frame as shown in fig4 and includes reinforcing bars 93 to inhibit damage to the antenna support 92 caused by the violent activities of the bison . the antenna supports 92 swingably support panels 94 by chain links , thereby permitting the panels 94 to depend in a vertical position due to gravity but to swing freely away from their position generally adjacent each feed cup 86 uninhibited by the reinforcing bars 93 . the antenna panels 94 are thus permitted to swing through a displacement corresponding to the size of the head of the bison at the respective feed station . as may be seen in fig2 each panel 94 is positioned near the upright rim 96 of each feed cup 86 for positioning proximate the transponder ear tag 120 worn by even the smallest bison calf , and is of sufficient size to substantially obscure the peripheral vision to one side of a feeding bison . each panel 94 incorporates an antenna 98 which is oriented on its respective panel 94 to be positioned adjacent the ear tag of the feeding bison . exemplary antennas 98 useful with the present invention include nedap antennas part no . 7600488 which are typically supplied with the nedap interrogator identified above but which are preferably separated for use in the bison feeder hereof , the antennas being of sufficient size and durability to withstand contact with the bison when mounted on or incorporated in the swingable panels 94 . it is understood that all of the bison in the herd would wear their tag on the same ear , in this instance the right ear , to ensure the antenna is sufficiently proximate the tag to interrogate the ear tag and receive the signal emitted thereby . such methods of interrogation are generally described in u . s . pat . no . 4 , 798 , 175 to townsend et al ., the disclosure of which is incorporated herein by reference . the feed storage unit 16 includes the medication hoppers 70 for each feed station and the main feed hopper 72 which is common to each of the feed stations . the main feed hopper 72 receives the feed into auger feed box 78 which houses the feed dispensing augers 68 which are located in substantially parallel alignment . the auger feed box 78 is located at the bottom of the main feed hopper 72 for gravity feed as illustrated in fig2 . the main feed hopper includes an upper unit which is generally circular in cross - section and is provided with a removable roof section 100 which may be accessed by a ladder coupled to the uprights 28 and removed or repositioned by lines attached thereto . the roof section 100 may be removed to provide access for recharging the main feed hopper with the desired feed . the main feed hopper 72 is secured by bolts or other fasteners to the uprights 28 . the animal separators 20 include a plurality of shiftably mounted legs 102 which may be carried in a generally inboard position underneath the main feed hopper 72 during travel and held by pins 108 or the like inserted through receivers 104 fixed relative to the frame 12 . each of the receivers 104 carries a strut 112 . the strut may be shifted vertically from an upper transport position to a lower stabilizing position , each strut 112 resting on a baseplate 114 . pins extending through holes in both the strut 112 and a collar 116 hold the strut in either the desired transport or stabilizing position . the legs 102 are preferably at least six feet or more in length to provide good separation between the bison at each feeding station and inhibit their ability to fight during feeding . because of the combative nature of the animal , a wire mesh fence 118 extends between the uprights to protect the feed chutes and dispensing augers from injury due to curious or combative bison . a vision - impairing plate 106 is of a triangular configuration and extends between the uprights 28 and the receivers 104 to obscure the vision of bison feeding at adjacent feed stations 48 , 50 and 52 . in addition , a ladder may be provided along one side of the main feed hopper to facilitate access to tile roof section 100 . finally , the side of the main feed hopper may be provided with a plurality of openings and covered with transparent material such as glass or resin to determine the level of feed in the main feed hopper 72 . in the preferred embodiment of the bison feeder 10 hereof , an insecticide administration system 122 is provided for spraying the bison with an insecticide during feeding . the insecticide system 122 includes spray stations 124 , 126 and 128 corresponding to respective feed stations 48 , 50 and 52 . each spray station 124 , 126 and 128 includes a solenoid unit 130 , fluidically coupled to spray nozzles 132 and 134 . an exemplary solenoid unit 130 may include a dayton relay model no . 1a487f 24 volt dc mounted on an h - pin no . 5x853f square type socket and connected to dayton solenoid coil model 3a439 24 volt dc in a dayton solenoid valve body model no . 1a576 . it may be appreciated that nozzles 132 , being positioned closest to the panels 94 , direct a spray pattern toward the hind end or body portion of the animal , while the nozzles 134 are opposite the panels 94 and direct a spray pattern toward the feeding bisons head , all as shown in fig2 . each solenoid unit 130 is connected to a respective output on an interrogator 46 . interrogator 46a is illustrative , showing augers 66 and 68 and solenoid unit 130 for one &# 39 ; spray station 124 / feed station 48 electrically coupled to respective outlets of the interrogator . each solenoid unit acts as control valve to selectively permit the flow of liquid spray to the respective nozzles responsive to signals received from the interrogator . fig8 illustrates the hydraulic circuit of the insecticide system 122 which includes reservoir 136 , pump 138 , pressure gauge 140 and mixing valve 142 . the reservoir 136 , pump 138 , pressure gauge 140 and mixing valve 142 are connected in a loop of conduit 144 , such as vinyl tubing , to maintain pressure within the system 122 and to ensure mixing of the contents of the reservoir 136 . when the system 122 is sufficiently pressurized , the mixing valve 142 opens to permit bypass of the insecticide back to the reservoir 136 to mix the contents thereof . t - connections 146 connect the spray stations 124 , 126 and 128 to the conduit 144 whereby insecticide is delivered on demand to the solenoids 130 . a 9 gallon recreational vehicle water reservoir has been found sufficient for most uses in storing the insecticide . one pump 138 useful in the present invention is a shurflo model no . 2088 - 403 - 444 12 volt dc receiving current from the battery or from the generator or 110 volt ac current passing through a voltage converter . the pump 138 pressurizes the system 122 to a suitable pressure , such as 45 psi . an enclosure 148 located adjacent the controller unit 14 contains the reservoir pump 138 , pressure gauge 140 and mixing valve 142 . during use , the main feed hopper 72 and each of the medication hoppers 70 are filled with bison feed and any medication to be administered orally such as for worming or the like . with power supplied via conventional utility current , a remote power generator , or solar - generated electrical power , the central processing unit is then programmed for each bison in the herd . for example , certain bison may be substantially mature and require only a maintenance ration . other bison , such as lactating cows or young bison experiencing rapid growth , may require additional feed and nutritional supplements . after appropriate transponder ear tags 120 , such as part no . 9821554 by nedap , have been placed on each of the bison &# 39 ; s right ears , the bison feeder is ready for operation . by predepositing a portion of feed into each feed cup 86 , bison can be conditioned to approach the feeder 10 for feeding . as the bison &# 39 ; s head comes down into a feeding position at the feeding site , reflected by the feed cup 86 hereof , the interrogator 46 initiates a magnetic pulse through the antenna 98 which causes the ear tag 120 of the animal to generate a corresponding signal unique to that ear tag 120 / bison . because of the positioning of the feed cup 86 , the bison &# 39 ; s head is positioned so that the transponder ear tag 120 is located proximate the antenna . the identifying signal is received by the antenna and communicated through the interrogator to the central processing unit 44 . the bison is identified by the central processing unit , which in turn signals the medication dispensing auger 66 and feed dispensing auger 68 to rotate their auger screws 82 one turn . this dispenses approximately 1 / 4 pound of feed or medication through the feed chute 74 and the conduit 84 to the feed cup 86 . it is contemplated that only a small portion of medication would be distributed relative to the feed from the main feed hopper 72 . thus , only a portion of the desired ration would be delivered during the initial interrogation . on second and subsequent interrogations , preferably occurring at about 20 - second intervals , the feed dispensing auger 68 and , if necessary , the medication dispensing auger 66 would rotate their auger screws an additional turn to dispense additional feed or medication , all provided that the bison &# 39 ; s ear tag remains sufficiently proximate the antenna to generate a responsive signal . this process would continue at 20 - second intervals until the successive portions delivered equal the entire pre - programmed ration for that particular bison , as programmed into the central processing unit 44 , is delivered . thereafter , the bison corresponding to that particular identification tag 120 would receive no additional feed for that feeding period , notwithstanding a return to the bison feeder 10 during that feeding period . for example , if a large dominant bison consumed its total ration , it could not return later for a second total ration until the next feeding period , for example one day . even if that dominant bison were to chase away a less dominant bison , it could only &# 34 ; steal &# 34 ; a small portion of that less dominant animal &# 39 ; s feed from the feed cup 86 . when the less dominant animal returned , it would be identified by its ear tag and the remainder of its total ration would be delivered in small portions until it had received its entire ration . if the feeding period is daily , the internal clock of the central processing unit would indicate when the previous period had expired and on the next day , each bison would be able to receive its next daily ration . the controller unit 14 also includes a printer . the printer receives reports from the central processing unit 44 which enables the printer to provide a report of the status of each bison in the herd . this is particularly advantageous for range animals as a sick or missing bison can be identified by its absence from the feeding report . the legs 102 assist in separating the bison during feeding . instead of the bison observing other animals in the herd during feeding at the bison feeder 10 , the plates 106 obstruct the bison &# 39 ; s vision and limit agitation of the animals due to competition during feeding . moreover , the extended legs serve to separate the bison from one another , so that only one bison is generally found at a respective feed station 48 , 50 and 52 . on the other hand , the legs are positioned at broad open angles so that the bison do not feel confined during feeding and resist approaching the bison feeder 10 . once the bison feeder has exhausted its supply of feed in the main feed hopper 72 , the legs may be shifted to the transport position and the tow bar 22 positioned on an automotive vehicle so that the bison feeder 10 may be towed to a feed bin for recharging or maintenance . an insecticide or insect repellant , and more particularly any conventional livestock fly spray may be applied to the animals during feeding at the feed stations 48 , 50 and 52 corresponding to the respective spraying stations 124 , 126 and 128 . for example , one of the many acceptable sprays known to livestock ranchers is sold under the trademark ectiban , which may be sprayed in the vicinity of the animal &# 39 ; s feed without substantial risk of toxicity to the animal . preferably , a spray duration of about four seconds has been sufficient to provide adequate coverage . the spray is preferably applied during the initial feeding during each cycle , such as a 24 hour period as programmed into the interrogator . as each bison is initially identified for the feeding cycle period , such as the first feeding of the day , as the signal from the transponder in the ear tag 120 is recognized by the antenna 98 , the interrogator signals the solenoid 130 at the respective spray station to permit the flow of insecticide to the spray nozzles . after the programmed duration of the spray is completed , the solenoid 130 closes and no further spray is administered for the cycle . it is to be understood that the rancher may desire multiple sprayings during the time cycle and that the insecticide administration system may readily be adapted to this end by one skilled in the art . the bison may then continue to feed until its ration is consumed . by administering the spray during feeding at the feed station , the bison is less likely to be alarmed , and the bison is likely to remain stationary to receive better coverage of the spray . although preferred forms of the invention have been described above , it is to be recognized that such disclosure is by way of illustration only , and should not be utilized in a limiting sense in interpreting the scope of the present invention . obvious modifications to the exemplary embodiments , as hereinabove set forth , could be readily made by those skilled in the art without departing from the spirit of the present invention . the inventor hereby states his intent to rely on the doctrine of equivalents to determine and assess the reasonably fair scope of his invention as pertains to any apparatus not materially departing from but outside the liberal scope of the invention as set out in the following claims .
a feeder for bison and other herd - type animals , particularly those difficult to domesticate , includes a feed storage unit having a feed compartment for holding animal feed , a frame for carrying the storage unit , a feed dispensing unit for delivering feed from the compartment , a controller unit for identifying the animal to be fed , and actuating the dispensing unit to deliver a ration of animal feed in response to the identification signal received . the feeder preferably includes a plurality of dispensing units for feeding several animals at different sites . legs located between the feeding sites separate the animals during feeding , and visual barriers inhibit the feeding animals from seeing one another . preferably , only portions of the feed are intermittently delivered by the dispensing unit so that dominant animals are inhibited from appropriating the share of lesser animals in the herd .