as seen in fig1 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 fig2 , 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 fig6 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 fig6 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 fig3 , 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 . fig9 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 fig7 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 fig4 , 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 . fig5 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 . * 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 .
a hog farrowing system for use in a cold environment includes a building providing protection from weather elements . the farrowing boxes have an entrance to permit free ingress and egress of female hogs but restrain the piglets . an alley is provided outside the boxes for the female hogs to defecate , urinate , and move to feed and water stations outside the boxes . the boxes have sides which define an inner chamber , a heat system , bedding for the female hogs to nest , and insulation covering an open top during cold environment conditions . the method utilizes the steps of promoting the female hog to utilize natural instincts , promoting the female hog to give birth to piglets close to the heat source , and protecting the piglets from crushing by using a creep area , anti - crush rods and anti - crush boards . the farrowing boxes can be modified for use in a warm season .