Method and system for feeding furred animals with dry fodder
BACKGROUND AND SUMMARY OF THE INVENTION 
     The present invention relates to a method of effecting feeding in fur farms, primarily in mink farms. Traditionally mink feeding is carried out by delivering some times during the day a paste-like wet fodder, which is placed in lumps on the net top of the cages, from where the animals can pick down the fodder. The delivery may take place by means of a fodder cart, which is designed to enable the operator, by means of a discharge hose, to dose out rather accurate fodder portions to the single cages. As the minks, by nature, are mainly night animals it would be good if they could be fed also some times during the night, but that would involve considerable costs due to the need of personnel. For this reason, inter alia, the use of self feeding dispensers holding dry fodder in the form of pills has become increasingly common, these pills being well suited for use in reasonably large portions in such dispensers, as the pill material is much less perishable than the wet fodder. In such dry feeding systems it is sufficient, therefore, to fill up the dispensers at intervals of, say, one or few days, and in the meantime the animals may serve themselves both day and night. 
     It has been found however, that not either the latter feeding method is also not perfect. The ample or unrestricted access to the dry fodder in the dispensers seems to result in the animals by concentrated eating being surfeited and supine, whereby they sleep much and do not show the growth they ought to. Probably it would be advantageous if the easy access to the fodder could be made less easy, but a restriction of the supply flow could easily result in a total blocking up of the flow, and in fact it is already a problem that blockings may occur in the dry fodder dispensers used so far. 
     It is the purpose of the invention to provide a method, whereby a practically optimal feeding is achievable. 
     The invention is based on the finding that by an automatically controlled discharge of the dry fodder from the dispensers several important advantages are achievable, viz. (1) The feeding may be effected at all desired times, during the day and particularly during the night, without any need of attention other than possibly necessary for the supply of relatively large fodder portions to the dispensers within normal working hours, (2) The feeding may be effected by fodder portions sufficiently small to ensure that the animals cannot overfill themselves, yet sufficiently large to be handled by relatively coarse dispension means without causing any blocking thereof or therein, i.e. a safe feeding is achievable by a fodder supply which is restricted, not by a general supply flow restriction, but by the restriction conditioned by an intermittent operation of the associated feeding dispenser, and (3) The very come-out of the intermittent feedings will contribute to keep the animals active, as they will both feel and get used to the turning up of fodder portions, by day and not least by night, which portions will be all the same attractive, just because the animals will not get surfeited with any of them. Observations have shown that the animals will hereby show a noticeably improved growth and that the fodder is utilized much more effectively. 
     It is readily admitted that in connection with some other kinds of animal breeding it is well known to use automatic feeding systems, but apparently it has not until now been realized that such systems, properly adapted for the purpose, will be usable with quite special advantages in the breeding of minks. 
     The invention also comprises the relevant feeding systems and the associated, automatically operated feeding dispensers. While the known self-feeding dispensers operate under the condition that the fodder is supplied quite slowly, depending the animal&#39;s eating of the fodder, the dispensers according to the invention will operate by intermittent dumping of relatively large fodder portions, whereby the risk of the supply being blocked will be considerably reduced. The same dumpings with their associated small shakings from the applied operation movements will act wakening on slumbering animals, whereby these are activated in an advantageous manner. 
     As a practical example, some 70 g fodder should be supplied per animal per 24 hours, of which 30-40% should be supplied during the day hours between 7 a.m. and 5 p.m. and the rest during the evening and the night. The single doses should be of the magnitude 10 grammes. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     In the following the invention is described in more detail with reference to the drawing, in which 
     FIG. 1 is a schematic perspective view of a row of mink cages provided with a feeding system according to the invention, 
     FIG. 2 is a perspective view of a dispenser as used in the system, 
     FIG. 3 is a perspective exploded view of the interior parts of a modified dispenser, and 
     FIGS. 4-6 are perspective views, partly in section, of the lower end portion of such a modified dispenser. 
    
    
     DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS 
     In FIG. 1 is shown a row of cages 2 each provided with a feeding dispenser 4 comprising an upwardly open tube 5, which is fillable with dry fodder from above and has a built-in portioning downlet valve, which is operable by an upper pivot lever 6 to sluice down a fodder portion to the lower end of the tube 5, in which there is provided a side opening 8, through which the let-down fodder is accessible for the animal or animals in the single cage. The pivot levers 6 are coupled to an actuation rod 10, which is reciprocably displaceable from a driving station 12 for pivoting the levers 6 forth and back and therewith for actuation of the respective associated downlet valves. The driving station 12 may be controlled by a timer, such that the dosing out of the single fodder portions may be effected automatically at all desired times of the day and night and, as mentioned, even predominantly during the evening and the night. 
     The dispensers 4 may be designed in many different manners, a well usable embodiment being shown in FIG. 2, adapted to be operated by the pivoting movement of the upper actuator lever 6. This lever is connected with a downwardly extending shaft 14 stretching through an upper storage chamber 16 of the tube pipe 4 down to a downlet valve structure mounted just above the side opening 8. The valve structure comprises an upper, intermediate bottom block member 18, which is rigidly fastened to the tube 4 and has a top surface downwardly vaulted towards an outer, axial through passage 20, and, underneath the block member 18, a thick disc 22, which is in rigid connection with the shaft 14 and has an outer, axial through passage 24, which, by a pivoting of the lever 6 may be rotated to and from a position just underneath the upper passage 20. Underneath the disc 22 is mounted another disc 26, which is rigidly fastened to the tube 4 and has an axial through passage 28, the cross sectional shape of which corresponds to that of the passages 20 and 24, but which is peripherally staggered from the upper passage 20 in such a manner that the passage 24 in the rotatable disc 22 by a pivoting forth and back of the lever 6 will be movable between opposed positions, in which the passage 24 will correspond with the passages 20 and 28, respectively. 
     In this manner there is provided a downlet valve, in which fodder portions are measured out in the passage 24 and are brought to fall freely down through the bottom passage 28 to the bottom of the tube 4 when the lever 6 is operated. It can be chosen to utilize a &#34;normal function&#34;, by which the passage 24 is not moved into full debouching into the outlet passage, such that only a part of the fodder portion will be discharged; by an adjustment of the end positions of the actuator rod it is then, when desired, possible to produce an increase or a decrease of the fodder doses. Such general adjustments may be desirable during certain periods of time, e.g. just before the pairing period. 
     The tube 4 may be designed telescopically with a lower end portion 30 provided with the hole 8 and consisting e.g. of stainless steel, and an upper pipe portion 32 which is secured to the cage in any suitable manner, whereby the height position of the eating opening 8 and the associated bottom of the said end portion 30 may be adjusted according to the requirements. 
     The fodder may be filled into the chambers 16 manually or by supply from an automatic conveyor, e.g. as known from hog feeding systems. The dosing out of the fodder portions could even be arranged to take place directly from such a conveyor system in the desired intermittent manner. 
     In the dispenser according to FIG. 2 the shaft 14 may be provided with radially projecting stirring pins down in the chamber 16, whereby possible formations of holding bridges in the fodder material may be counteracted. The pronounced concavity of the upper valve block member 18 towards the passage 20 results in the fodder sinking down all over the cross section of the chamber 16, so that no part of the material will stand still during the successive feeding operations and thus not become tainted. 
     FIGS. 3-5 show a preferred design of the valve in the dispenser. Here the upper valve block member is a thin disc 18&#39; having two opposed notches 20&#39;, while the intermediate thick disc 22&#39; has two notches 24&#39; similar to the notches 20&#39;, but located next to each other, separated by a narrow wing portion 34. The lower valve disc 26&#39; has but a single similar notch 28&#39;. As in FIG. 2 the intermediate member 22&#39; is connected with the shaft 14, while the two outer members 18&#39; and 26&#39; are rigidly held in the tube 4, with their respective notches 20&#39; and 28&#39; out of registry. On the top of the upper disc 18&#39; is placed a cross block member 36, which is rigidly connected with the shaft 14, such that in operation it will be turned between the opposed positions shown in FIGS. 4 and 6, respectively. 
     The valve here discussed is a double acting valve which will deliver a fodder portion as housed in either of the notch passages 24&#39; through the bottom notch 28&#39; each time the lever 6 is pivoted in either direction. In that respect the drawings are believed to be self-explanatory, and it just remains to be added that the upper cross member 36 will serve to scrape material rested on the flat top disc 18&#39; into the respective opposite notches 20&#39;, such that the material cannot collect or be left resting on the top disc. This again results in the material sinking through the chamber 16 all over the cross section thereof. 
     The invention is not limited to the rotary arrangement of the valve system, since as already well known the intermediate valve member 22, 22&#39; of a dosing outlet valve may be arranged to move in a linear manner. 
     It will be relevant to effect some 5-15 feedings per 24 hours, preferably 6-8 feedings, and more than the half of them should be effected during the evening and night hours. 
     The said conveyor system for supplying fodder to the dispensers is shown only very schematically at 40 in FIG. 1.