Self-feeder for Hogs
by G. Bohstedt, Agricultural Experiment Station, University of Wisconsin, Madison, 1931 – Bulletin 419
Self-feeders have proved efficient and economical on thousands of farms where pigs are raised. Perhaps the best reason for the popularity of self-feeders, aside from their saving of labor or backache, is that pigs are especially adapted to self-feeding.
As a rule, pigs do not overeat when they first use a self-feeder, and for this reason are little troubled with digestive disorders. Self-feeders are a boon to fall pigs, too, for hand-feeding them leaves a long stretch during cold winter nights when their little stomachs crave feed. A self-feeder at such times is an excellent pantry for them.
Pigs Are “Food-wise”
Pigs have been called the most “food-wise” animals on the farm; and the way they use a self-feeder is a convincing argument for such a statement. When the self-feeder allows a choice of various feeds that supply protein, carbohydrates, minerals, and vitamins such as corn and the “trio mixture,” the pigs will soon learn to select the different kinds in the right amounts to balance their ration. In other words the “cafeteria system” places the responsibility for a correct ration upon the pig rather than upon his caretaker; and the pig usually proves himself able to satisfy his own nutritional needs. Smaller pigs in a group also have a better chance to eat with self- feeding than they do with hand-feeding.
Where self-feeding has been compared with hand-feeding, the latter has proved just as efficient and economical in a number of experiments. Of course, it must be remembered that in such instances the self-feeding scheme, which could be practiced successfully almost anywhere, was compared with well regulated and methodical hand-feeding, as is the rule at experiment stations whenever hand-feeding is done. Such regularity would not be possible on most farms. In general, therefore, self-feeding is more economical than hand-feeding.
Plan Self-feeder Properly
Self-feeders should be built to withstand rough use and, if used outdoors, to protect the feed from the rain. The self-feeder should also permit feed to come down into the trough with the least amount of clogging. The trough part of the self-feeder is very important and should be built to prevent pigs from rooting feed out of the trough on to the ground and wasting it.
The pigs are usually eager to get at the cleanest and sweetest portion of the feed as it trickles down into the trough of the self-feeder, and if there is an accumulation of feed they are apt to nose the rest out on the floor to be trampled or soiled and wasted. It is always a good plan to stand self-feeders on concrete or wooden platforms so that if any feed is rooted out, this may not be trampled in the mud. Efficient self-feeders deliver small amounts of feed into the trough but do so in a dependable manner and do not become clogged or “dead.”
An Adjustable Slide Essential
An obvious necessity for self-feeders is an adjustable opening at the base or throat of the hopper so as to regulate the flow of feed. This adjusting is usually done by means of a slide at the side of the hopper facing the pigs. The whole side wall may act as a slide.
The feed moves down more freely if special agitating devices are used which are movable by the pigs as they “root” in the trough. After the feed has reached the trough, however, it should all be eaten and not pile up and be easily thrown out by the pigs.
In an effort to make as efficient and dependable a self-feeder as possible, the feeding habits of pigs were studied closely, resulting in the design of a self-feeder of which pictures, plans, and specifications are presented in this bulletin. It is a self-feeder 5 feet long, 2 feet wide, 3 feet 5 inches high in front, and 3 feet 2 inches in the rear, holding 10 bushels of feed and accommodating 25 pigs, or 5 pigs to each stall or trough space, each of which is one foot wide. Two such feeders would serve nearly three times as many pigs, or 7 to a stall. Much larger feed capacity may be secured, if desired, through a superstructure for the feeder, as through putting a box on top, or through using the self-filling scheme shown in Figure 8.
The front of the trough is as much as 10 inches high from the ground for it has been found that a relatively high front helped to prevent a wastage of feed. The hopper is arranged in two compartments, 1 foot and 4 feet wide, so as to permit, if desired, self-feeding grain and protein supplement separately. The forward wall or side of the hopper constitutes the slide regulating the flow of feed. This slide may be adjusted easily without wrench or other tool by simply loosening the clamping nut of the tie rod, adjusting the slide up or down by means of the large wooden handle, and again tightening the clamping nut. Since the whole side wall makes up the slide, by pulling it up as high as necessary, all feed may be easily removed from the front as desired. The self- feeder may be easily moved about by means of the large iron handles on either end.
Means of Agitation
A device for agitating the feed downward is shown in Figures 6, 7, and also 12. Standard 9-gauge, 3×6 inch mesh, electrically-welded woven wire fencing is attached to the inside slope of the front wall of the hopper by being stapled and clamped to the top but free-swinging below. This wire is agitated rearward by pigs through the bunting of free-swinging wooden panels that hang suspended from the slide in the trough of the self-feeder. The purpose of the agitated woven wire fencing is to cause the moving down of any feed that may otherwise tend to form an arch in the hopper, leaving a vacant or “dead” space underneath.
The free-swinging wooden flaps are slammed against the turned lower edge of the woven wire that projects through the notched openings of the lower edge of the slide, as indicated in Figures 6, 7 and 12.
This principle of slamming and in that way vibrating the woven wire and slide is rather effective in jarring down feed in a way which ordinary pushing or pressing against a flap would not do, especially if this flap acted as a baffle for the feed back of it. Such a flap would be difficult to push inward against a solid wall of feed.
In order to have the flaps as free swinging as possible, it is necessary to alter the three inch strap hinges slightly. The regular tight-fitting pin of the hinge is removed after filing away its riveted end. The usual tight lateral fit of the two members of the hinge is loosened considerably by filing one of the inside bearing surfaces, as indicated in Figure 14. Then by substituting a cut-off ten-penny nail for the original pin and riveting the cut-off end, this will leave a loose-jointed hinge that assures the desired freedom for the small swinging flap or panel which is supported by a pair of such hinges. Loose hinges are absolutely essential, for otherwise the small flaps hang stiffly and cannot be slammed against the wire and slide. Yellow pine is heavier than white pine and is to be preferred for making the flaps because weight renders these more effective for agitating purposes.
This means of agitating feed in a self-feeder has not been found necessary with most feeds or feed mixtures but is of help when certain bulky mixtures are fed, especially those containing considerable ground oats and chopped or cut alfalfa hay. With certain feed mixtures enough jarring down of feed may be brought about by the pigs agitating the flaps against the slide, or side wall of the hopper, even if no woven wire is installed. There is considerable vibration and consequent trickling down of feed, when the flaps are slammed against the side walls. The slide with flap but without woven wire is presented in Figures 5, 7 and 11.
The Design of the Trough
More essential than the agitating devices is the design of the trough. Its depth is an advantage, not to permit the accumulation of a huge amount of feed, for that is not wanted, but to discourage raking or rooting out feed as much as possible. This principle of conservation is further aided by the partitions in the trough that are only a foot apart and that have side cleats which baffle in a sidewise raking out of feed. The trough itself, on the inside, leaves a vertical drop of two inches from the top before it slopes to the bottom. Each trough compartment therefore, resembles an inclined bucket with a turned-in rim to keep feed inside.
If at times the feed comes down too rapidly, the depth of the trough will take care of it in a way that a shallow trough will not. Weanling pigs, to be sure, will need to place their forefeet in the trough of a self-feeder in order to be able to eat out of such a high trough, but it is practically impossible to keep them from putting their feet into almost any trough, large or small. Weanling pigs may be aided, however, in their access to this rather high trough by placing a ledge along the front of it; but by the time they reach a weight of about 75 pounds, they will be found to keep their feet out of the trough. About this time they also begin to agitate the free-swinging flaps if their self-feeders should be so equipped. The ripped 1 1?4 x 1 1?4 inch pieces in the trough, and its slope from front to rear, keep feed from becoming foul in the corners of the trough that are inaccessible to pigs.
The trough is metal covered on the inside so as to keep pigs from damaging it and especially chewing through the bottom of it. Heavy 22-gauge galvanized iron is employed for this purpose in the trough. This sheet metal protection which also includes the edges of the partitions more than any other thing renders this self-feeder durable, for any self-feeder is vulnerable especially in the part where feed is eaten.
The galvanized iron of the trough is extended rearward to cover the deflector which when sheeted this way and inclined at an angle of 52 degrees with the floor aids a downward passage of the feed. The best way of bending this galvanized iron is on a sheet metal brake of a tinsmith or hardware store.
Can Be Used Outdoors
No attempt has been made to keep rain out of the trough by covers or flaps in case this self-feeder should be used outdoors. We may say, however, that we have used this and similar one-way self-feeders for years outdoors as well as indoors, finding that if hogs were there to eat the feed they would soon clean out the trough even though a driving rainstorm had moistened the feed in the trough. Little difficulty will be experienced from water in the trough of such a self-feeder if the trough-side is placed away from the direction of prevailing storms. Further sheltering of the trough may be secured through having a metal cover of the self-feeder extending well forward.
Chickens may be kept out of the trough by board panels hinged from above at the front of the self-feeder and swinging inward.
Indoor Use. – This self-feeder is a one-way type and, therefore, designed primarily for use indoors where it may be set along a wall or in a corner, thus economizing in space. When thus used a cover is not usually necessary although many hog growers prefer a cover even for indoor feeding.
Self-filling self-feeder. – A chute leading down from a convenient overhead feed bin may at times be arranged to keep the self-feeder filled so that it requires very little attention. Figure 8 indicates a self-filling arrangement which permits of many modifications.
Bill of Material for Wisconsin Self-feeder
13 – 1”x6”x12’ matched flooring, No. 2 white pine
3 – 1”x6”x12’ plain No. 2 white pine
1 – 1”x8”x12’ plain No. 2 white pine
1 – 2”x8”x5’ plain No. 2 white pine
1 – 2”x4”x6’ plain No. 2 white pine
1 – 2”x2”x16’ plain No. 2 white pine
2 – 7/8”x1-1?4”x10’ plain No. 2 white pine
1 – 1-1?4”x1-1?4”x10’ plain No. 2 white pine
1 – 1-1?4”x1-1?4”x16’ (ripped diagonally) plain No. 2 white pine
Extra lumber for self-feeder with flaps:
1 – 1”x6”x5’ plain No. 2 yellow pine
1 – 3/8” iron rod with clamping nut, 5’3” (tie rod)
1 – 1?2” iron rod, 3’8” (handles at ends)
1 – 3/16”x1-1?4”x10” strap iron (tie rod plates)
1 – 36”x5’ heavy galvanized iron, 22 gauge (trough)
1 – 16”x8’ light galvanized iron, 28 gauge (slides, trough partitions, and
front ends of partition cleats)
1 – 36”x69” light galvanized iron, 28 gauge (cover)
1 – pair 3” strap hinges (cover)
1 – light chain 30”, with 2 staples (cover)
8 – bolts, 1?4”x2” (handles at ends)
2 – bolts, 1?4”x3-1?2” (slide handle)
4 – 7/8” wood screws (plates for tie rod)
2 lb. 6-penny nails
1?2 lb. 10-penny nails
1?4 lb. 1” nails, 3?4” brads, tacks
Extra hardware for self-feeder with flaps:
5 pair 3” strap hinges
Extra hardware for self-feeder with both flaps and woven wire agitators:
5 pair 3” strap hinges
5 feet electric welded woven wire fencing, 36” high, 3”x6” mesh, No. 9 wire
1 – 3/16”x1-1?4”x50” strap iron (for clamping woven wire)
4 bolts, 5/16”x2-1?4” with wing nuts
Back: 12 – 1”x6”x38” matched flooring
Slide: 12 – 1”x6”x36” matched flooring
Ends and partition: 12 – 1”x6”x4’ matched flooring
Deflector: 3 – 1”x6”x5’ matched flooring
Floor: 3 – 1”x6”x5’ matched flooring
Casing, (cleats) rear, ends, partition: 1 – 1”x6”x12’ plain
Cleats for slides and flaps (flaps, yellow pine): 3 – 1”x6”x5’ plain
Trough partitions: 1 – 1”x8”x6’ plain
Front board, top: 1 – 1”x8”x5’ plain
Front of trough: 1 – 2”x8”x5’ plain
Bottom, underneath, at ends and middle, front to rear: 1 – 2”x4”x6’ plain
Bottom, underneath, end to end, and deflector braces: 1 – 2”x2”x16’ plain
Strips supporting slides: 8 – 7/8”x1-1?4”x2-1/2’
Short cleats: 1 – 1-1?4”x1-1?4”x10’
Corner strips: 1 – 1-1?4”x1-1?4”x16’ ripped diagonally
Cover, front board: 1 – 1”x6”x5’8”
Cover, sides and rear: 1 – 1”x3”x10’
Using a Self-Feeder for Fattening Pigs
Self-feeding “Free Choice”
A very efficient dry-lot feeding scheme is to place shelled corn or ground barley or other suitable grain or grain mixture in the large compartment of the self-feeder, and the so-called “trio mixture” in the small compartment. The “trio mixture” is made up of two parts tankage, one part linseed meal, and one part ground alfalfa hay, by weight. Pigs will then balance their ration them- selves, from weaning to market weights.
One-half per cent salt in the feed is usually a satisfactory allowance and this may be mixed with both grain and protein supplement. In case pigs should have a craving for more salt, it is a good practice to let the pigs have access to block salt in addition to that which they get out of their feed.
Self-feeding Grain and Hand-feeding Dairy By-products
Skimmilk and buttermilk are excellent protein feeds and if sufficient amounts of these milk by-products may be obtained, they render the purchase of tankage or other high-protein feeds unnecessary. Even whey has proved a good supplement to such a grain as barley. These dairy by-products should not be self-fed for they will spoil if more is self-fed than will be cleaned up at each feeding. A good plan is to simply self-feed corn or barley or other grain, and then in addition feed by hand twice a day enough of the dairy by-product to balance the ration.
Much less skimmilk or buttermilk is needed to provide a balanced ration which will produce rapid gains than is commonly believed. To pigs fed without pasture the following amounts should be supplied: just after weaning, 4 to 6 pounds of skimmilk to every pound of corn will be sufficient to make maximum gains with pigs in dry-lot. As the pigs grow older the proportion of skimmilk or buttermilk needed to balance the ration decreases as follows: pigs weighing 50 to 100 pounds, 3 pounds milk to one pound corn; pigs weighing 100 to 150 pounds, 2 to 2.5 pounds milk to one pound corn; pigs weighing 150 to 200 pounds or over, 1.5 to 2 pounds or less to one pound corn. What this amounts to is this, that during the larger part of the feeding period a market pig would need about one gallon of skimmilk per day together with all the corn he wants. Less skimmilk would be required with barley or other small grain.
Pigs fed simply grain and skimmilk or buttermilk in the winter time or in dry-lot should have access to leafy alfalfa or other legume hay in a suitable rack so as to avoid stiffness or rickets. If the grain is ground for the pigs and hay may also be ground, it is a good plan to mix about 5 pounds of ground hay and 5 pounds of linseed meal with 90 pounds of the grain.
Pigs that are fed corn on such pasture as clover, rape, oats with peas and rape, or alfalfa, will need only about one-half as much skimmilk or buttermilk as indicated above.
Considerably more milk than this may be fed with satisfactory results when a surplus is at hand. It will not, however, have as high a value per 100 pounds as when only enough is fed to balance the ration.
Trials at this station have shown that barley self-fed and whey hand-fed at the rate of 2 pounds or more for every pound of barley, make an excellent ration for fattening pigs over 100 pounds in weight at the start. Younger pigs needed a little tankage, linseed meal, or other protein-rich feed in addition to the barley and whey. Even for pigs over 100 pounds in weight, if corn (which contains less protein than barley) is used instead of barley it is best to feed a little tankage, linseed meal, or wheat middlings in addition to the whey in order to balance the ration.
Self-feeding Prepared Mixtures in Dry-lot
It may be advisable at times, where dairy by-products cannot be fed and where dependence must be placed on purchased protein supplements, to feed the entire ration in a mixture. Such feeds as tankage, fishmeal, linseed meal, soybean meal, or other high protein feeds, are comparatively expensive, but nevertheless may be consumed by the pigs in somewhat greater proportions to the corn or carbohydrate part of the ration than is most economical. Again, feeds that are somewhat unpalatable but nevertheless essential may be eaten in more nearly proper amounts than when offered separately to the animals.
For many years one of the most efficient rations for fattening pigs was made up of corn and tankage, but since the development of the “trio mixture” of tankage two parts, linseed meal one part, and ground alfalfa hay one part, this combination with corn or other grain is a standard ration that is considerably superior to merely tankage with grain. Using the “trio mixture” the following proportions furnish a balanced ration:
• Suckling pigs, 10 to 40 pounds – ground corn 70, “trio mixture” 30 parts.
• Weanling pigs, 30 to 75 pounds – ground corn 78, “trio mixture” 22 parts.
• Shoats, 75 to 150 pounds – ground corn 85, “trio mixture” 15 parts.
• Hogs, 150 to 225 pounds – ground corn 90, “trio mixture” 10 parts.
Since in the above mixture for suckling pigs, one-fourth of the “trio mixture” is alfalfa meal, the entire mixture, therefore, contain 7.5 per cent of this roughage. This is a rather high proportion of fiber or bulk for such very young animals. For this reason the amount of alfalfa meal had better be reduced to about half the amount indicated when intended for suckling pigs. Fattening pigs at no time should receive much more than 5 per cent alfalfa meal in their ration.
Corn contains about 10 per cent and standard feeding tankage 60 per cent protein. When corn is replaced entirely or partly by barley, rye, oats, or wheat, which contain from 11.5 to 12.5 per cent protein, a somewhat smaller proportion of protein supplement may be fed. The addition of wheat middlings, which contain about 17 per cent protein, still further cuts down the required proportion of tankage.
A high protein feed of animal origin such as tankage, meat meal, fishmeal, or skimmilk, is highly desirable in dry-lot or winter rations of pigs, and if swine raising pays at all, these feeds are usually economical. If, however, such feeds are not available and dependence must be placed on protein feeds of vegetable nature such as linseed meal, soybean meal, peanut meal, or perhaps limited amounts of cottonseed meal, it is essential that the pigs receive minerals in addition to salt, such as ground limestone and steamed bone meal. In a strictly grain or vegetable ration for pigs, usually from one to two pounds of limestone or the mixture of limestone and steamed bone meal in every 100 pounds of the grain mixture is sufficient.
Where in extensive experimental work at the Wisconsin Experiment Station minerals of various sorts were fed with grain, tankage, linseed meal, and alfalfa hay in the winter, or without the alfalfa hay but on pasture in the summer, there was no benefit that could be attributed to the feeding of these additional minerals. Good rations, therefore, that include efficient animal protein feeds as well as leafy legume hay, do not, in most cases, require the addition of minerals other than salt and at times iodine or iodized salt.
Self-feeding on Pasture
Tests at the Wisconsin and other experiment stations have shown that when pigs are carried to a market weight of 200 to 225 pounds, self-feeding pigs on pasture saves feed per pound of gain as compared with light hand-feeding. Self-fed or full-fed pigs naturally make larger gains and therefore reach an early and usually better market ahead of the others. Self-feeding on pasture has another advantage in that it facilitates the rotation of pastures for pigs and thus keeps pigs on clean, uncontaminated ground.
As compared with dry-lot feeding, pigs on pasture, whether self-fed or not, require much less supplementary protein feeds. However, pasture and such a concentrate as corn alone make an unbalanced ration and should be supplemented by such feeds as skimmilk, tankage, linseed meal, soybean meal, or middlings.
When growing and fattening pigs are self-fed corn or barley and tankage and salt separately on good pasture, they usually eat about 1/3 pound tankage daily per pig with enough grain to satisfy them. They eat about the same amount of tankage whether on alfalfa, clover, rape or blue grass until about midsummer when the blue grass beings to get dry and unpalatable, and when the pigs will often consume nearly twice as much tankage. This shows that good pasture saves expensive protein feed. In addition pasture furnishes an abundance of growth-promoting and health-giving vitamins and easily assimilable minerals so that feedings pigs on pasture is a much simpler problem than is winter or dry-lot feeding.
Self-feeding Breeding Stock
A self-feeder has its place chiefly in the production of market hogs. Pigs usually lay on fat readily when fed such concentrated feeds as corn and a suitable protein supplement whether on pasture or not. For developing breeding stock self-feeding has been successful at times where considerable ground hay was mixed in the ration and where the rate of gain or growth of the pigs, boars or gilts, was gauged by the proportion of bulky ground hay and oats or middlings in the mixture in a self-feeder.
Self-fed pigs, whether market or breeding pigs, are apt to patronize the self-feeder more than pasture for which reason it is usually preferable to hand-feed breeding stock so as to have them make greater use of pasture or forage crops.
Brood sows with large litters and therefore needing a great deal of feed in order to properly nourish their suckling pigs and to keep from losing much weight, may well be self-fed after the pigs are from 2 to 3 weeks old. Feeding these suckling pigs liberally through their dam is usually an economical practice.
Watering Pigs on Self-feeders
Since the pigs are obliged to eat dry feed they crave water more frequently during the day, especially during hot days, than do pigs that are slop-fed. It is essential, therefore, that self-fed pigs should have access to water several times a day and preferably from a self-filling fountain that supplies clean water at all times.