Taking equal parts of necessity, scraps from the metal pile and a teaching state-of-mind, the lead instructor of swine management courses at Iowa's Kirkwood Community College came up with a brand new twist to individual sow feeders.

Arlin Kartsen, DVM, assistant professor of animal science at the Cedar Rapids, IA, school was faced with replacing the rapidly deteriorating feeding tubes in the school's 10-year-old, breeding-gestation barn. He began thinking about ways to get sows to eat slower and eliminate feed thievery by sows in adjoining gestation stalls.

The Feeder

Karsten's working prototype includes a 5 ft. length of 2⅜-in., straight steel tubing that can be easily connected to standard, volumetric feed dispensers. The bottom of the tube is cut at a 45° angle. A 1-in. wide by 3-in. tall slot is cut into the low end of the angle cut.

A 2½-in. outer tube, 5 in. long, is also cut at a 45° angle. Two ½-in. rods, about an inch long, are welded to this sleeve — one on the inside, the other on the outside. The inside rod slides into the 1 × 3-in. slot and has two purposes — to agitate the feed and to serve as a stop that hits the top of the slot. The outside rod gives the sow a “handle” to raise the outside tube with her nose (see photos).

A steel plate, roughly 3 × 6 in., is welded to the angle-cut inner tube so that it extends about an inch below the point of the inner tube, resting on the floor. The plate keeps the lowest part of the slot about an inch off the floor to prevent moisture from being wicked up into the feed tube.

“The outer tube restricts the movement of the feed to the sow's feeding area,” explains Karsten. “Feed is delivered in limited amounts as the sow raises the outer tube by lifting on the outer stud with her snout.”

The Benefits

Karsten emphasizes the benefits he sees are strictly observations that must be confirmed with properly conducted research trials. He lists these benefits:

  • Feeding accuracy is dramatically improved. “Sows rapidly develop an eating pattern whereby they consume the limited amount of feed delivered by several lifts of the outer tube before discharging additional feed,” he says. “The limited amount of diet on the feeding surface, discharge of the feed through the small opening and the bottom plate all serve to obstruct sows in the adjacent crates from consuming feed outside of the targeted amount delivered to each sow's individual eating space.”

    The feeder allows side-by-side housing of sows with large variations in targeted daily feed intakes, allowing sows to be fed to condition more accurately.

  • With the old feeders, water troughs at the front of sow stalls were drained before feed was dropped through tubes directly into the trough. With the new feeders, troughs are not drained so sows have continual access to water and it stays much cleaner, he says.

    “This is particularly apparent in the case of unoccupied stalls where spilled feed leads to mold formation in the common water and feed trough. Since the feed tube is not placed over the water, mold formation within the tube is also eliminated.” And, automatic floats have eliminated the twice-daily job of filling the water trough.

  • Rapid gorge feeding has been completely eliminated. Sows take three to four times longer to consume equal amounts of their daily diet.

    “The extended feeding period, with increased production of saliva and associated enzymes, would most likely have a positive impact on the occurrence of gastric ulcers and other digestive diseases,” the veterinarian/instructor points out. “The feeding tube may allow gestation diets to be ground finer, theoretically improving feed efficiency.”

  • Sows appear to be calmer before and after feeding. “Sham chewing, head weaving, head pressing and squealing and other stereotypical behaviors have been almost entirely eliminated,” he says. “Sows do not press on the front gate in attempts to retrieve feed spilled into the alleyway.”

  • Sows spend more time standing and moving. This has two advantages. Theoretically, the more active behavior should develop and strengthen muscles and improve sows' locomotion and agility. Practically, this greater standing activity helps work manure through the slotted floors. The rear of the stalls and the sows themselves remain cleaner. Scraping within the sow's stall has been virtually eliminated and the need to scrape alleyways is minimal.



The Payback

Karsten estimates the new feeder costs about $14.50 more than conventional drop tube feeders, bringing the total to just under $26/sow space.

“The real point that will get a producer's attention will be if we can improve the overall feeding accuracy, feed efficiency and labor requirements. Observations to date indicate the tubes will have a 1-2 year payback. Additional research trials will be designed to further quantify the economics for a typical producer,” he says.

Student Observations

Karsten challenged students to observe the sows and offer suggestions for improving the feeder. Here are a couple of student observations:

Scott Wulfekuhle of Dyersville, IA, notes: “When we dropped feed directly in their trough (old system), the sows would get up right away and defend their own feed and try to eat it quickly. With the new feeder, they eat what they want at the speed they want.” And, he adds: “These tubes are easier to make because they don't have bends in the tube. The bend is where they wear out.”

Aaron Penner of Story City, IA, compares the new feeder to traditional drop feeders in an 800-sow operation back home. “With this feeder, sows are a lot more calm. They don't spill feed in the alleyway and that keeps the barn cleaner.”

Research to Come

The Iowa Pork Industry Center recently earmarked funds for Karsten and Iowa State University Swine Field Specialist Larry McMullen to compare the sow-activated feeder to traditional drop feeding tubes. The 24-week pilot project will evaluate two groups of 12 sows for the following:

  • Accuracy of feed delivery and consumption;

  • Body condition scores (monitored every two weeks by measuring backfat cover over the last rib, body weight change plus visual condition scores);

  • Sows will be videotaped for 24-hour periods at six separate points in the test. An animal behaviorist will interpret sow behaviors.

  • Conception rates, farrowing rates, litter size born alive, number of pigs weaned, litter weights and days to estrous will also be compared.



After the initial trial, the Pork Industry Center plans to conduct larger field trials that attempt to quantify cortisol levels, an indicator of the sow's response to stress, by measuring blood or urine samples.

Field-testing of labor requirements for the feeder in a new 1,400-sow commercial herd in southeastern Iowa is currently underway.

Several companies have expressed an interested in fabricating the non-patented feeder, some making slight modifications.