Patent Document

BACKGROUND OF THE INVENTION 
   The present invention relates generally to hog farrowing systems and specifically to a hog farrowing system for use in cold environments which permits unrestricted female hog movement and promotes natural mothering instincts of the female hog. 
   Conventional farrowing systems isolate pregnant female hogs within a steel cage prior to them farrowing a litter of piglets. The cage has a bottom grate through which the female hog defecates and urinates. Water and feed troughs are provided in the cage and feed must be hand delivered to the cage. This conventional farrowing system does not permit the female hog to move except for standing up and lying down. This conventional system does not accommodate the female hog&#39;s natural mothering instinct to build a nest and consequently the female hog will rub her snout along the floor of the cage and chew on the steel bars of the cage. The associated stresses with the conventional farrowing system leads to physical injury, infection of the mammary glands, and low milk let-down. In addition, the conventional system is more labor intensive because they must have feed hand transported directly to the female hog. 
   Farrowing systems have been developed to counteract the stresses and pressures encountered by female hogs in conventional farrowing systems. Summer pasture hut farrowing is well suited to provide a mothering female hog with a farrowing environment free of man-made stresses. In this environment, a female hog is free-ranging in a pasture. The most obvious issues with summer pasturing of farrowing systems is that the weather elements become an issue in the fall, winter, and spring. Therefore, an objective of the present invention is to develop a farrowing system that may be used in a cold environment but have the characteristics of summer pasture hut farrowing that include unrestricted female hog movement in and out of farrowing boxes and promote natural mothering instincts such as building a nest for her litter. 
   Simulating pasture hut farrowing within an enclosed building is not an easy endeavor particularly in cold weather climates which may withstand typical temperatures at or below −12° F. and wind chills approaching −35° F. Accordingly, it is a further objective of the present invention to provide a farrowing system which permits female hogs to farrow and express their natural instincts during cold weather as they would in summer pasture hut farrowing. 
   An indoor farrowing system is still further complicated when engaging inhumane on-farm husbandry with criteria such as providing housing that is spacious enough for a mothering female hog to lie down in full lateral recumbency at one time and to move freely; providing an environment so that the female hogs may be active and social; providing the hogs continuous access to bedding with straw or corn stover in which they can root, explore, play or build nests; and providing continuous access to shelter that protects the female hog and her piglets from cold, wind and rain. Accordingly, a further objective of the present invention is to provide a farrowing system which incorporates general humane on-farm husbandry standards for farrowing hogs. 
   Conventional farming techniques using cages are often used by large corporate farms. These large farms are not typically inclined to utilize humane on-farm husbandry for farrowing hogs. A family farm that owns the hogs, depends upon the farm for its livelihood, and provides the daily physical labor to manage the hogs and farm operations are more likely to adopt humane on-farm husbandry. Accordingly, it is a still further objective of the present invention to provide a farrowing system which may be easily adapted to a family farm and modify existing buildings so that a family farmer may make a livelihood from the farm. 
   Conventional farrowing systems have no standards which require buildings to be constructed with windows or openings that let in daylight. In addition, conventional systems are not given sufficient space to keep defecation and urination areas separate from female hog eating areas. Accordingly, a still further objective of the present invention is to provide buildings constructed with windows or openings that let in daylight and have sufficient floor space to keep the defecation and urination area separate from the feeding and drinking areas. 
   Conventional farrowing systems have also aspired to remove the piglets from the mother at as early an age as 2 weeks. A humane husbandry guideline is that weaning shall take place at a piglet weight or age that considers the health and welfare of both the piglets and their mothers. Although this age/weight may vary depending upon the breed of the female hog, whether the female hog is a sow (a female hog that has had a litter of piglets) or a gilt (a female hog that has not had a litter of piglets), and the health of the individual piglets, the recommended weaning age is typically six weeks with a minimum weaning age of five weeks. Accordingly, it is a still further objective of the present invention to provide a weaning of piglets that considers both the health and welfare of the piglets and their mother. 
   A still further objective of the present invention is to provide adequate space requirements for animals if they are not free ranging in pastures but are instead in an enclosed building structure. The Animal Welfare Institute recommends 42 square feet for a gilt and her litter. Accordingly, it is a still further objective of the present invention to provide adequate space for the female mothering hog and her litter of piglets. In addition, a further objective of the present invention is to provide apparatus to prevent two female hog from occupying the same space. 
   These and other objectives will become apparent from the following description of the invention. 
   BRIEF SUMMARY OF THE INVENTION 
   A hog farrowing system for use in a cold environment is provided that incorporates and utilizes the female hog&#39;s natural behaviors and instincts. These behaviors and instincts include:
         to isolate herself from the herd 24 hours before farrowing;   to seek a warm, dry area to root and nest in;   to begin nest building 12–15 hours before farrowing;   to vocalize with and nurse pigs immediately after farrowing;   to seek to defecate and urinate away from her nest;   to find her own nest and piglets based on scent;   to keep her piglets isolated from the herd for 10–14 days;   after 10–14 days the female hog wants her piglets to follow her to integrate with the rest of the herd; and   at 5–6 weeks the female hog begins to move away from the piglets and starts the gradual weaning process by limiting nursing time which encourages the piglets to begin consuming more dry feed.       

   The foregoing objectives as seen in the background of the invention and the incorporation of the above natural behaviors and instincts may be achieved with a hog farrowing system for use in a cold environment. The farrowing system has a farrowing building providing protection from the weather elements, and farrowing boxes within the farrowing building. The farrowing boxes have an entrance to permit free ingress and egress of female hogs and restrain piglets. The farrowing system has an alley outside the farrowing boxes where the female hogs defecate, urinate, and move to feed and water stations. 
   According to another aspect of the present invention, the farrowing building does not need to be heated or insulated. In fact, the farrowing building may be a previously built hoop barn or pole barn already present on the farm. 
   According to another feature of the present invention the farrowing boxes are insulated and utilize a heat system. The heat system may be a centralized system being ducted into the farrowing boxes or may utilize simple heat lamps. The heat system is located opposite an entrance to the farrowing box to permit the female hog to lie facing the entrance and give birth to piglets near the heat. 
   According to another aspect of the present invention the farrowing boxes have a removable door to permit free ingress and egress of piglets to defecate, urinate, and move to the feed and water stations when the piglets have achieved an age of approximately 10–14 days. 
   According to another feature of the present invention, the farrowing boxes may have a roller located over the removable door to prevent bruising of the female hogs large pre-farrowing underline and udder. 
   According to another feature of the present invention the farrowing system may have limestone bedding placed under the farrowing boxes and the farrowing boxes have an open bottom to be placed directly on the limestone. In addition to the limestone bedding, straw bedding may be placed within the farrowing boxes to permit the female hogs to build a nest within a center location of the farrowing box. 
   According to yet another feature of the present invention the farrowing system may have anti-crushing boards, anti-crushing bars, and a creep area placed away from the nest in the center location of the farrowing box to prevent the female hog from crushing the piglets. 
   According to yet another feature of the present invention, the farrowing box may adopt the Animal Welfare Institutes space requirements of a female hog that is a gilt utilizing 42 square feet per gilt and litter. 
   According to yet another feature of the present invention, the farrowing system places a ring in the female hog&#39;s snout to prevent rooting in the alley of the farrowing building. 
   The foregoing objectives may also be achieved by a method of farrowing hogs in cold environments using a farrowing building and farrowing boxes. These structures in combination permit unrestricted female hog movement and promote natural mothering instincts by the female hog. The method provides a female hog for each of the farrowing boxes approximately 24 hours before the female hog gives birth to piglets. Amongst other features, the farrowing building utilizes an alley outside the farrowing box so the female hog can defecate, urinate, and move towards feed and water stations. The method promotes the female hog&#39;s instinct to root in bedding provided inside the farrowing box to build a centrally located nest. The method also has the step of promoting the female hog to give birth to piglets close to the heat source and then protecting the piglets from crushing by use of a creep area, anti-crush boards, and rods preventing two female hogs from laying within the same farrowing box. 
   According to another feature of the present invention the method utilizes the step of weaning the piglets after approximately 6 weeks by removing the female hogs and then removing the piglets at the end of the farrowing cycle which is approximately 8 weeks. 
   According to yet another feature of the present invention, steps are provided for removing the nesting boxes, cleaning the bedding material within the building, spreading new bedding upon the farrowing building floor, and returning the farrowing boxes to an operational position. 
   According to yet another feature of the present invention, steps are provided for maintaining the minimum temperature in the creep area under the heat source at 70° F. and the nest within the farrowing box at 50° F. and ideally 90° F. in the creep area and 70° F. within the farrowing box. 
   A still further feature of the present invention is utilization of a once bred gilt system which brings a gilt to market within 11½ months as a market hog. The gilt is considered a market hog that produces a litter of pigs on her way to market. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of the farrowing system of the present invention showing a grouping of farrowing boxes within a generic hoop building. 
       FIG. 2  is a top view of the farrowing building of  FIG. 1  showing the layout of the farrowing system. 
       FIG. 3  is a perspective view showing the structure of the farrowing box. 
       FIG. 4  is a perspective view of the farrowing box in use with piglets inside the nesting area of the box. 
       FIG. 5  is a perspective view of the farrowing box with piglets nursing with their mother. 
       FIG. 6  is a cross sectional view of the farrowing box taken along line  6 — 6  of  FIG. 4 . 
       FIG. 7  is a front view of the farrowing box with a carpet over the entrance to the farrowing box. 
       FIG. 8  is an alternate embodiment of the farrowing box as seen in  FIG. 7  with plastic curtain. 
       FIG. 9  is a top view of the farrowing box showing anti-crushing bars moveable between a nesting position and a nursing position. 
   

   DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
   As seen in  FIGS. 1 and 2 , the farrowing system is generally designated in the drawings with the reference numeral  10 . The farrowing system may also be referred to as the NATURAL FARROWING SYSTEM™. The farrowing system utilizes a generic farrowing building  12 , typically a hoop or pole barn. The floor of the farrowing building has a farrowing box area  14  which has a series of farrowing boxes  16  grouped together. The farrowing box  16  may also be referred to as NESTING BOX™. 
   As illustrated, the farrowing boxes  16  are grouped together to conserve heat. Alternatively, these boxes may be separated. Also, the farrowing boxes  16  as illustrated have their backs to one another such that an entrance to the farrowing box  16  is pointed outward. The farrowing boxes  16  may also be formed in a single lane. The number of farrowing boxes  16  are determinate upon the size of the farrowing building  12  and general guidelines regarding layout of the farrowing building  12 . 
   Layout considerations include an alley  18  outside of the farrowing box  16  that is preferably 6 to 7 feet wide. Also, a 12 feet wide floored area  20  extends along the front of the farrowing building  12  and includes a waterer  24  that is approximately 8 inches off the ground and a feeder  22  that as illustrated is 8 feet high and holds several weeks worth of feed. In addition, the farmer may desire a storage area  26  behind the farrowing box area  14  in which to store straw. The storage area  26  is optional and not required. 
   As seen in  FIG. 2 , the relative size of the components is illustrated. As illustrated, the farrowing boxes are 8 feet long and 5′ 4″ wide to give each farrowing box 42 square feet inside. Each alley  18  to the left and the right of the farrowing box area  14  is 7 feet wide bringing the total width of the building to 30 feet. The total length of the building is 50 feet which provides adequate storage space  26  and a forward area  20 . 
   The generic farrowing building  12  as illustrated is a hoop building that protects the farrowing boxes  16  from snow, wind, and rain. The structure should be 14 feet wide to accommodate one 8 foot long nesting box and a 6 foot wide alley and have a length to accommodate as many 5′ 4″ farrowing boxes  16  as can be placed in the barn  12  for each female hog that is farrowing. The floor of the farrowing building  12  may be dirt, concrete, or other material. The floor is illustrated in  FIG. 6  as numeral  70 . 
   The entire floor of the building  12  is covered with a half inch of Ag lime #3. This layer is illustrated in  FIG. 6  as numeral  66  and acts as a disinfectant and barrier to pathogens in the floor. The area of the floor under the nesting boxes is bedded with a 4 inch layer shell and bone dry lime stone  68  to insulate gilt. To encourage the female hog to nest, ⅓ to ½ of a small bale of long stemmed straw (20 lbs) illustrated as numeral  64  is placed in the farrowing box  16 . 
   As seen in  FIG. 3 , the farrowing box  16  has a front  28 , back  30 , both having cross bars  31  for structural support. Joining the back  30  to the front  28  are sides  32  which are attached to the back  28  and front  30  by corner braces  33 . The front  28 , back  30 , and sides  32  together form an open bottom  34  and an open top  36 . On the front  28  is an entrance  37  positioned over a removable door  38  that slides along grooves  40  on each side of the entrance  37 . Above the removable door  38  is a 4″ by 24″ plastic roller  42  that helps the female hog prevent damaging her pre-farrowing underside and udder. The plastic roller  42  may be used with the above described farrowing box  16 , summer pasture hut farrowing boxes, or other farrowing environments in the prior art. 
   On each side of the farrowing box  16  are anti-crush boards  44 . These boards  44  help prevent the piglets from being crushed up against sides  32  accidentally by the female hog. Crossbars  46  extend across the front and back sides of the farrowing box. The plastic roller  42  is placed upon the front crossbar  46  during construction and spins about the front crossbar  46 . 
   Also seen within the nesting area are rods  48 . These rods prevent two female hogs from lying down and sharing a farrowing box  16  together. As mentioned earlier, gilts are social animals and will sometimes co-mingle in the same farrowing box  16  without the use of rods  48 . The rods  48  enable a female hog to maneuver within the box  16  but not to lay down except within a center channel in alignment with the entrance thus preventing piglet crushing. 
     FIG. 9  illustrates anti-crush rods  48  which are moveable between a nesting position where the rods  48  are extended outward to permit the pre-farrowing female hog to build a nest without obstructions of the rods  48  and a nursing position wherein the rods are moved parallel such that only one female hog may lay in the farrowing box at a time to nurse her piglets. The nursing position significantly prevents piglet crushing by preventing two female hogs from being with the same farrowing box  16  at the same time and to designate an area where the nursing mother may lay which further prevents piglet crushing. 
   The rod  48  is moveable between the nesting position and the nursing position. The rod  48  may be used with the above described farrowing box, summer pasture hut farrowing boxes, or other farrowing environments in the prior art. The rod  48  is supported by a U-bolt  81  affixed under the front crossboard  46 . The rod  48  travels through the U-bolt  81  and a pin  80  placed through the rod prevent the rod  48  from moving outward into the inner nesting area. A hole  82  within the creep area crossboard  46  is raised off the ground approximately 12″ to effectively remove the rod  48  from interfering with the nesting of the female hog. Downward support bars  84  are on the outside of the wooden crossboard  46  and extend about 4″ downward. The downward support bars  84  permit the rod  48  to be slid into place at approximately 8″ off the floor of the farrowing box  16 . In addition, the bars  84  also deter the mothering hogs from pushing material into the creep area. The rod  48  is a ¾″ steel pipe that will not be damaged by the female hog. The rod  48  is moved between the nesting and nursing positions by removing pin  80 , pushing the rod  48  into the nesting area and then pulling the rod  48  through the entrance  37  which removes the rod  48  out of hole  82 , the rod  48  is then placed into the bars  84 , and finally the rod  48  is placed into the U-bolt  81  and the pin  80  placed through the rod  48  to prevent movement past the U-bolt  81 . The rod  48  is moved between the nursing and nesting positions similarly but with reverse order of steps. 
   A sloped creep front  50  is in position at the back  30  of the farrowing box  16 . This is sloped forward and has holes  52  through which wiring  54  runs to lamps  56 . The sloped creep front  50  defines a creep area level with the anti-crush boards  44 . A mesh wire abuts the bottom of the creep area and prevents straw bedding  64  from touching the lamps  56 . The farrowing box  16  as shown is equipped with two 250 watt heat lamps  56 . These heat lamps  56  maintain a minimum 70° F. temperature in the creep area and a minimum of 50° F. in the nesting/nursing area. Ideally, the heat lamps  56  maintain a 90° F. temperature in the creep area and a 70° F. in the nesting/nursing area. The heat lamps  56  may be controlled by a thermostat. The heat lamps  56  maintain these temperatures even when the external temperatures outside the farrowing building are at −12° F. with a −35° F. wind chill. 
   The heat lamps  56  are protected from the female hog and piglets by the solid plywood barrier  50 . The wire mesh  58  is ¼ inch wire mesh and is an effective barrier below the heat lamp to prevent the heat lamps from contacting the straw bedding and to prevent the lamp from straw contact from the nesting female hog, and protect the piglets and female hog in the unlikely event that the lamps become loose or explode. 
   Insulation  62  is placed on the open top  36  of the farrowing box  16 . Additionally, a plastic vapor barrier  63  may be placed in use with the Styrofoam insulation  62 . The plastic vapor barrier  63  is typically a 6 ml clear plastic barrier. The insulation  62  is typically 2 inch thick Styrofoam panel (R10) heat loss barrier. 
   A covering may be placed upon the door to prevent heat loss out of the farrowing box  16 . As seen in  FIGS. 7 and 8 , this door  76  may be a 3×2 foot insulating carpet square or it may be insulating plastic sheets  78  overlapping. The plastic sheets  78  may provide the additional benefit of being clear and permitting a female hog to see within the farrowing box  16 . 
   As seen in  FIG. 4 , the piglets  73  are shown standing without their mother in the nesting area. The piglets  73  may alternatively rest underneath the heat lamps in the creep area or under the anti-crush boards  44  and anti-crushing rods  48 . 
     FIG. 5  illustrates a female hog  72  which may be a sow or gilt. Sows are older female hogs which have already had one litter and gilts are female hogs having their first litter. The female hog  72  is shown with a nose ring  74 . The nose ring  74  prevents the female hog  72  from rooting in the alley and encourages the female hog  72  to root and build a nest in the farrowing box  16 . 
   The use of the farrowing system will now be described. Approximately 12 hours before a gilt is due to farrow she will start looking for a nest site and will move into the farrowing box  16  and isolate herself from other female hogs. The 4″ inch plastic roller on the approximately 12 inch high entrance prevents any bruising of the female hogs  72  large pre-farrowing underline and udder. The female hog  72  will root in the 4″ dry limestone layer and proceed to build a nest with the straw that is provided in the farrowing box  16 . She will tend to mound the straw in the middle of the farrowing box  16  causing the newborn piglets  73  to move to the sides  32  under the anti-crushing boards  44 , anti-crush bars  48 , and under the sloped creep front  50 . The gilt will lie in the box facing the door and the piglets  73  will be born next to the heat source  56  in the creep area under the sloped creep front  50 . The female hog  72  is discouraged to farrow in the bare outside alley  18  because there is no nesting material, such as bone limestone  68  or straw bedding  64 , and because by instinct wants to isolate her new piglets  73  from the other female hogs. The female hog may have a ring  74  inserted in her snout to further prevent rooting in the alley  18 . 
   After farrowing, the female hog  72  will lie in the farrowing box  16  and vocalize and nurse her piglets  73  for about  12  hours before she will get up and go outside into the alley  18  to urinate and defecate. She will then go to the end of the farrowing building  12  and eat and drink from the feeder  22  and waterer  24 . 
   The female hog  72  will then go back to her farrowing box by scenting her piglets  73 . The female hog  72  will only go back into the farrowing box  16  holding her piglets  73  because of her mothering instinct. 
   The female hog  72  will nurse her piglets in the farrowing box  16  and continue to go outside over the farrowing box roller  42  to urinate, defecate, eat and drink. This results in the farrowing box  16  staying dry and warm for the piglets health and comfort. 
   After about 14 days the lower door  38  of the farrowing box  16  is removed and the piglets  73  will naturally start to follow their mother outside and integrate with the other piglets and mothers. The piglets will follow their mother to the end of the structure and will begin to eat and drink with her. The piglets also learn to urinate and defecate in the alley  18  and thus their farrowing box  16 , that they will always return to, will stay dry and warm. The farrowing box  16  will always provide the female hog  73  and her litter a safe haven from the environment outside the farrowing boxes  16 . 
   The piglets  73  continue to nurse their mother and eat and drink with her until about six weeks of age when they are weaned at approximately 35 pounds. Weaning is done by removing the female hog  72  from the area and by allowing the piglets  73  to stay in their normal environment which eliminates much of the weaning stress of the piglets  73 . 
   The piglets continue to each and drink from the self feeder  22  and waterer  24  at the end of the farrowing building. At eight weeks of age the piglets  73  are 50 to 55 pounds and marketed as feeder pigs and removed from the building. 
   For cleaning, the farrowing boxes  16  are removed from the building  12  by picking them up with a front end loader (not shown) attached by chain such that the cross beam  60  can be lifted up. The limestone  66  and  68 , straw  64  and manure are then mechanically removed with the front end loader and spread on crop ground as valuable natural fertilizer that is dry and virtually odor free. 
   The cycle begins again by placing a ½″ layer of Ag Lime #3 spread over the entire floor  70  of the building  12  as a disinfectant and barrier to pathogens in the floor. 
   The entire process is an eight-week cycle. The cycle is further enhanced utilizing a once-bred gilt system. This system utilizes a genetic line of hogs which reach reproductive maturity quickly. Ideally the female hogs are induced to go into heat by being placed near a boar such that their first heat is between 5½ to 6 months of age. The female hogs are then artificially inseminated such that they farrow at approximately 9¼ months of age. The mother may then be weaned at approximately 10½ to 11 months of age where they may then be marketed as market hogs. This is valuable because market hogs command a higher price than hogs older than one year of age. 
   During warm seasons, the insulation  62  and vapor barrier  63  are removed from the farrowing boxes and the heat lamps  56  turned off by thermostat. In addition, the farrowing building  12  may have windows and doors opened. Utilizing these steps, the farrowing system for cold environments may be modified to be used during the hot summer months. 
   As seen in the below table, the results of using the above-described cold farrowing system is as effective if not more effective than summer pasture hut farrowing. 
   
     
       
             
           
             
             
             
             
           
             
             
             
             
           
         
             
               TABLE 
             
           
           
             
                 
             
             
               Comparison of results between NATURAL FARROWING SYSTEM ™ and 
             
             
               Summer Pasture Hut Farrowing 
             
           
        
         
             
                 
                 
                 
               ISU Summer Pasture 
             
             
                 
                 
                 
               Hut Farrowing: 
             
             
                 
               NATURAL FARROWING 
               NATURAL FARROWING 
               Nine Year Research 
             
             
                 
               SYSTEM ™ 
               SYSTEM ™ 
               Summary on 513 
             
             
                 
               Feb. 18–Feb. 22, 2004* 
               Mar. 10–Mar. 14, 2004* 
               litters.** 
             
             
                 
                 
             
           
        
         
             
               Gilts Bred 
               30 
               30 
               513 
             
             
               Gilts Farrowed 
               26 
               27 
               429 
             
             
               Farrowing Rate % 
               86.77 
               90 
               83.6 
             
             
               Pigs Born/Gilt 
               10.30 
               10.41 
               9.70 
             
             
               Pigs Born Dead/Gilt 
               0.69 
               0.78 
               0.60 
             
             
               Pigs Born Alive/Gilt 
               9.61 
               9.63 
               9.10 
             
             
               Pigs Crushed/Gilt 
               1.22 
               0.81 
               0.90 
             
             
               Pigs/Gilt 
               8.39 
               8.82 
               8.20 
             
             
               Alive &gt; 24 hours 
             
             
               Pigs 
               218 
               238 
               3518 
             
             
               Alive &gt; 24 Hours/ 
             
             
               Farrowing Group 
             
             
                 
             
             
               *Results from cold weather farrowing in hoop building temperatures tested at −12° F. with a wind chill of −35° F. below. 
             
             
               **Outdoor Pig Production: A Pasture Farrowing Herd in Western Iowa Honeyman, Mark and Rousch, Wayne Publication Number ISRF98-10 
             
           
        
       
     
   
   The invention has been shown and described above for the preferred embodiments, and it is understood that many modifications, substitutions, and additions may be made which are within the intended spirit and scope of the invention. In the foregoing, it can be seen that the present invention accomplishes at least all of its stated objectives in a cold environment and with minor modifications can be used in warm seasons to improve pasture hut farrowing results.

Technology Category: a