The ’90s design offers a compromise between stalls
and pens for gestating sows.
If you are among the legions of pork producers struggling to decide if and when to move from individual gestation stalls to some type of group housing, the turnaround stall introduced in the '90s might just be the ticket.
Over 20 years ago, under the guidance of animal scientist Stan Curtis, researchers at the University of Illinois experimented with a modified stall design that was 7 ft. long, 22 or 24 in. wide in the front two-thirds, then flared out to 48 in. at the back. The idea was that a sow or gilt would learn to wriggle her body into the rear portion of the stall so she could turn around. The 250-to 300-lb. gilts soon figured out how to turn around in the limited space, Curtis explains.
Richard Balsbaugh with Moorman Mfg. Co. soon became intrigued with the concept, and suggested it would be much easier for the sows and gilts to turn around if a portion of the stall's sides could swing freely from side to side. The adaptation was soon made, leaving about 2.5 ft. of the front dividers as stationary, with the remaining 4.5 ft. of the dividers mounted on brackets so they could swing in and out. When swung to the maximum width, the rear portion of the stall was 65-72 in. wide, depending on how loosely the adjustable chain on the back of the gate was set (see diagram).
Early research reports caught the eye of a few creative pork producers who began tinkering with various stall widths and the lengths of the pivoting dividers.
Balsbaugh, in collaboration with Illinois researchers and Ian Taylor, also with Moorman Mfg., eventually standardized the materials and dimensions — 2.3-ft. fixed (open bar) divider, 4.5-ft. swinging gate divider — and patented the MoorComfort design in April 1990. The patent was transferred to Hog Slat, Inc. when they acquired MoorMan's Livestock Equipment division. The patent has expired, but the rights to manufacture the stall remain with Hog Slat, Balsbaugh explains.
The sow zone, as Curtis refers to the basic 2 × 7-ft. turnaround design, requires the same space as standard gestation stalls. “But when a sow spreads the sides to their fully splayed positions, she increases her floor space by more than 70% — from 14 sq. ft. to about 24 sq. ft. — very near the European Communities' regulations requirement of 25 sq. ft. for Parity 2 or older pregnant sows,” he says.
Widely recognized for his research in animal behavior and well-being, Curtis remains an enthusiastic advocate of the turnaround design, and he thinks it merits another look.
A search for pork producers who had experience with the turnaround stall design turned up one in Minnesota, Iowa and Missouri, respectively. All agreed that the turnaround stalls definitely had strengths and weaknesses.
Pat Weber of Lawler, IA, worked with 2 × 7-ft., stationary gestation stalls for 15 years and spent seven years managing sows in the MoorComfort stalls.
The 1,800-sow, farrow-to-nursery Multi-Pig complex was built in west-central Iowa in 1974. Weber joined the firm in 1976. By the early '90s, the original stalls were about worn out and the timely introduction of the MoorComfort stalls caught their eye. Over the course of a year, 720 gestation stalls were replaced with MoorComfort stalls.
“They were not a cheaper alternative,” Weber explains. “I believe they were $25-30 more expensive than a conventional stall, but we decided to be more proactive about animal welfare because we thought it would eventually become a bigger issue.”
Veteran purebred seedstock producer and National Pork Board member Everett Forkner of Richards, MO, had graduated from outdoor sow lots to Cargill-style, open-front breeding-gestation facilities. By the mid-'90s, Forkner had his fill of battling the elements, so plans for a new breeding-gestation barn were on the drawing board. The new barn was equipped with 22 × 84-in. conventional gestation stalls and 8 × 8-ft. breeding pens, plus 18 custom-made, 24-in. × 9-ft. MoorComfort stalls and a few 30-in. × 9-ft. custom-made turnaround stalls for large herd boars.
“When we finally got around to putting sows in stalls, I very quickly decided this was so much better than anything I'd ever experienced. I was able to give sows individual attention and score sows for condition, and our conception and farrowing rates improved. I am thoroughly convinced that a sow is much better off in her own little cubicle, even if she can't turn around,” he says.
Still, Forkner believes more welfare-friendly sow housing options must be sought. “Perception is reality and the consumer is always right,” he states. “The reason we will never win the gestation stall battle is because if you ask anyone, in any walk of life, whether or not sows should have the freedom to turn around, logically they will say: ‘well, yeah, I think they should.’ It just doesn't sound right that she can't.”
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The Forkners wean 16-18 sows every Thursday, moving them directly to the turnaround stalls. “It's a welfare issue. They've been in the farrowing crate for about 27 days, so it seems logical to me that an opportunity to be a little more active might be a little bit better for the sows, physically,” Forkner explains.
After sows are bred, they are moved to standard gestation stalls and pregnancy checked 28-35 days later. By 40-50 days post-breeding, demand for standard gestation stalls forces Forkner to move groups of six sows or 7-8 bred gilts to 8 × 16-ft. pens for the remainder of their gestation.
Forkner sees the 40-50-day stay in stalls as a transitionary period when he can full-feed sows if necessary to get them back into good body condition while ensuring they are safely pregnant before moving them to group housing.
Gary Thome, a commercial producer from Adams, MN, got a jump on the turnaround design when he saw a preliminary report in a Moorman Mfg. publication in 1988. This early exposure corresponded with an opportunity to purchase gestation stalls from a renovated barn.
Thome cut the rear 4 ft. off the 2 × 7-ft. stalls and hired a local fabricator to build the swinging gates. A solid ⅝-in. drop rod holds the swinging gate brackets in place and a ⅝-in. log chain anchors the gates to the wall. “When sows pushed both gates apart as far as they could go, they had nearly three full sow spaces (66 in.) at the back to turn around,” he explains.
Thome weaned sows every other week, moving them to standard gestation/breeding stalls. Sows were pregnancy-checked at 28-32 days post-breeding, and confirmed sows were moved to the 130 turnaround stalls for the balance of their gestation.
Thome and his sons, Matt and Pat, recently joined another Minnesota family in the purchase of a 6,250-sow, breed-to-wean unit in Iowa. Each family will take delivery of 2,500 pigs every other week, so after 20 years of service, the stalls are being removed to convert the barn to a nursery.
In separate settings, each producer shared their thoughts about the turnaround stall concept and offered some ideas on how they might fit sow housing in the future:
The turnaround design addresses the animal welfarists' common concern about the sows' ability to turn around and socialize with others.
“The turnaround stall creates the liberty and the freedom for animals to be able to turn around and to move about a little more than a stationary stall,” Forkner says.
The turnaround design provides more space for sows to stand, walk, turn and groom themselves and adjacent sows. The 2 × 7-ft. design allows about 24 sq. ft. of space when swinging gates are splayed open to maximum width. Of course, as one sow sprawls across the back of her stall, she infringes on the space of her neighbors on both sides.
“Sometimes it's difficult for adjoining sows to get her attention so she will get up and move, but it's not a persistent problem,” Weber notes.
“It doesn't take them long to learn how to turn around,” Gary Thome assures. “By the time we would get the last of about 24 sows in the stalls, the whole works had turned around at least once already.”
“We try to fill the stalls biggest-to-smallest or vice versa,” Matt Thome adds. “They tend to be a little more neighborly when the sow next to them is the same size. One sow letting another turn around never seemed to be an issue.”
Longer and wider turnaround stalls were custom-made to fit larger sows and herd/heat-check boars for Forkner. “I felt the 30-in. × 9-ft. turnaround stalls were the best utilization of space to house mature boars in the AI stud, plus I'm always concerned about the longevity of purebred herd sires. In most cases, the boars have done well and thrived in them,” he says.
Pregnant sows and gilts can be individually fed according to parity and body condition. Sows can avoid confrontation with dominant, “boss” sows. “Having also managed sows in pens, it's easier to keep sows in good condition in turnaround stalls,” Gary Thome says. “Sows in the turnaround stalls were less likely to abort and they could get their feed without being bullied.”
Sows and gilts can be examined individually vs. identifying and isolating sick or injured females in a group. It is easier to provide individual care, such as pregnancy checking, vaccinations and treatments.
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The stalls provide an opportunity to manage environmental and sanitary conditions, avoiding the group's pecking order that relegates submissive sows to poorer microenvironments in group housing designs.
“Every once in a while we'd have a couple of sows that would fight between the bars, but they couldn't hurt each other,” Gary Thome explains.
Worker safety is improved as sows can be examined, treated and moved individually, with less stress.
Turnaround design requires less total space since floor space is shared with adjacent sows. Popular barn designs position turnaround stalls against outside walls, thus eliminating rear aisles and rear gates. All sows are moved in and out through the front gate.
At Multi-Pig, the MoorComfort stalls essentially matched the space of the standard gestation stalls they replaced, explains Weber.
“In certain situations, you can actually put more turnaround stalls in the same amount of space because you don't need a rear aisle. All you need is a 24-30-in. feeding aisle. That saves rear gating and rear aisles. Our problem was the existing, partially slotted floors didn't allow us to butt the new stalls against the wall,” he explains.
In the late '80s, when the Thomes expanded their sow herd, they converted 16-ft.-wide nursery rooms to gestation housing. The 7-ft. turnaround stalls were set in line against each wall, leaving a 2-ft. walkway down the center. “It was the only way we could make it work,” Pat Thome explains.
Through trial and error, they also learned the swinging gates should be less than 5 in. off the floor; otherwise, sows could get their heads caught under them. The end link of the chain was welded to a steel plate anchored into the wall studs. A ½-in. bolt was welded to the end of the gate so as to drop a link over the bolt and secure it, according to the length needed to swing into the adjoining stall. A washer and a lock nut secured the chain.
Weber says the stalls had no design flaws, but durability was a problem. “When you're working with hogs, you've got to keep things simple. Here we had a stall with moving parts. After 5-6 years, we started having problems with the hinge mechanism wearing and breaking off. Gates would tip and get wedged between the slats but, naturally, the sows still wanted to turn around,” he explains. “Once those moving parts and mechanics started breaking down, it was a nightmare.”
Weber left the Multi-Pig unit in 1997. “After I left, I was told that they were spending so much time repairing the stalls, they finally welded the swinging gates in place, leaving them with a traditional gestation stall,” he says.
“The framework and the gates weren't a problem, but the hinges on one end of the gate and chains on the other end are the two wear points. A heavier chain would solve one problem, but the hinge mechanism was the weak point that would have to be addressed before I'd consider them today,” Weber adds.
Forkner's answer to the chain durability issue is a ¼-in. stainless steel chain. “The hinges held up pretty good after 11 years,” he says.
All agreed that a locking mechanism to simultaneously lock the sows in place would be a good feature to aid in pregnancy testing, individual examination and vaccination.
“When we went to vaccinate, the sows would go stand along the wall,” Pat Thome says. “Some type of flipper to lock them all in place when you drop the feed would do the trick.”
The elder Thome agrees. “Before the boys were involved, I pregnancychecked sows before we moved them out of the breeding stalls; then, I'd go through and test them again 30 days later. I could check three sows from one stall, so checking 24 sows meant crawling across eight gates.”
Another drawback is the difficulty in identifying early abortions on slotted floors where fetal matter falls through the slots or sows consume it. “You don't get behind the sows to see any discharge,” explains Matt Thome. “If it occurs early in the pregnancy, it's hard to see them and find them open if they abort early.”
Removing sow mortalities is another tough task. More often than not, when a sow died, she would be lying cross-wise in the stall, so removing them in a timely manner is critical to the well-being of the adjoining sows.
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Noise levels tend to be higher. The swinging, banging gates and the jangling chains increase the noise levels in the barn. “There was definitely a lot of clinging and clanging when the sows moved around and chewed on the chains,” Weber explains. “The quietest time was 30 seconds after we started the feed augers — every sow is turned around, waiting. Otherwise, during the course of the day, they are always up and milling around.”
In the end, a question that remains is: “Will the turnaround stall be acceptable to the animal welfare advocates?”
“In the industry today, we have all of these options — small pens, large pens, electronic feeding stations — but I don't think we have enough science behind us to make a right decision,” Weber states.
“Can we define what is best and still keep us in business and efficient and also address the issues on the welfare side? If we're too hasty (in making the decision), it could cause other, bigger problems,” he warns.
An important part of most discussions about stalls centers on preserving the use of breeding/gestation stalls between weaning and the first 30-35 days of gestation.
“We keep hearing from the animal welfare people — often channeled through the food chain and the fast-food people — that the sows should have the freedom to turn around. If being able to turn around is really ‘the’ issue, I think we can sell them on turnaround breeding stalls if we can't sell them on conventional stalls (for early gestation). That may be the compromise,” Weber asserts.
Perhaps the most ringing endorsement of the turnaround design came from those who had worked with them the longest. “I would definitely put in turnaround stalls before I'd put sows in pens. No doubt in my mind,” Gary Thome says flatly. “After working with sows in pens, I agree,” Pat and Matt say in unison.
“If there is a midway point between stalls and pens — that's definitely it,” Gary Thome adds.