One made the transition voluntarily; the other by law.

Day zero for phasing out of gestation stalls for Smithfield Foods was Jan. 25, 2007, when they announced their intent to eliminate gestation stalls within 10 years in favor of loose sow housing for their company-owned sow farms.

The motivation behind the corporate decision to eliminate gestation stalls was feedback from their customer base. The task of the conversion fell to Murphy-Brown, LLC, the production arm of the corporate food giant.

The clock began ticking and the timeline was relatively short to decide which sow housing technology would replace the stalls, explains Chris Rademacher, DVM, of Murphy-Brown West, headquartered in Ames, IA.

During a sow housing workshop at the Leman Swine Conference in St. Paul, MN in mid-September, Rademacher walked his predominantly swine veterinarian audience through the decision-making process and shared some experiences at the midpoint of their self-imposed deadline.

The search began by examining the scientific literature, with an emphasis on how the various alternatives affected sow and pig performance.

In 2008, a team of 15 embarked on a study tour of Danish sow housing systems, which broke down roughly as 30-40% free-access stalls, 30-40% electronic sow feeding (ESF) systems and 20-30% pens. They learned the space allocation guidelines for gestating sow housing ranged from 16 to 26 sq. ft./sow, somewhat dependent upon sow age and group size.

The European specifications helped guide how the conversions would be made and how they fit with existing facilities and production targets, Rademacher explains. In addition, an industry survey helped identify performance differences between the three basic alternatives.

“We didn’t see any glaring, obvious differences in performance. But what really got us excited was there appeared to be better performance with free-access stalls vs. ESF or pens with slats or straw or both,” he says.

To advance their knowledge base and collect data using their genetics, management and feed, Murphy-Brown designated a 2,500-sow “evaluation farm” in Colorado to make side-by-side comparisons of sow performance with free-access stalls and small pens.

The free-access system pen configuration housed about 60 females/pen and allowed about 25 sq. ft./sow. Sows could come and go freely, spending their time in the stalls or the adjoining open-pen space. The free-access individual enclosures were equipped with self-closing rear gates. As a sow enters a free-access enclosure, she pushes on a plate that closes the rear gate behind her. To leave, pressure on the rear gate simply swings it up and out of the way.

Small pens were configured by removing the rear two-thirds of the gestation stalls, leaving the front portion as a head-and-shoulder guard to protect females as they drank or ate when the trickle-feeding system was engaged. These pens housed seven females per pen and provided 22 sq. ft./sow.

The cost difference to convert to free-access stalls vs. small pens was about $20/female space or roughly 1.5 cents/weaned pig, prorated over a 10-year depreciation schedule, he explains.

During the 31-month evaluation period (February 2008 to September 2010), they amassed data on about 9,500 litters from sows housed in small pens and 4,000 litters from sows housed in free-access stall pens. Sows in the free-access stalls had about a 0.17 pigs born alive/litter advantage, but a slightly higher (0.07 pigs/litter) stillborn rate.

“The big number for us was total pigs weaned/litter, which favored the free-access stall pens by nearly ½ pig per litter,” he says. The free-access stalls also averaged about ¾ sow per bred group less in sow mortality.

“One of the take-aways from the comparison was that most of the sows preferred to spend most of their time in the free-access enclosures. Sows are calmer and more likely to approach the caretaker as they walk through the free access area,” he observes. “In the small pen areas, as the manager walked through the facility, there was more vocalization and less interaction between the person and the sows. Sows tended to flee. Sows in the small pens act and sound different, and their inclination is to not come and greet the person,” he adds.

Goal Setting

“One of the ultimate goals of gestation housing is protection from the environment and protection from other sows — aggression issues, feed level control, pregnancy maintenance and well-being. In other words, our goal is to create a safe and enjoyable workplace for the animals and the people and a robust system to reduce management errors,” Rademacher explains. “We also wanted to make sure that the workforce has the management skills to ensure they are able to take care of the animals. Finally, we wanted to meet the financial needs of the business.”

One of the residual benefits of the corporate decision was that it provided the capital needed to re-engineer some of their operations. “Many of the facilities were approaching 15-20 years of age and were in need of some renovation,” he notes. “It allowed us to do some facility improvements, supplied some capital to improve gilt development methods and allowed us to move toward an older weaning age across our system, which has benefitted the sows and the growing pigs downstream.”

Because all of the facilities were not built at the same time by the same company, it takes a lot of engineering to properly install the retrofits to fit within the confines of the existing structure. “Each sow farm was evaluated separately,” he says.

With the facility upgrade, it is equally important to focus on upgrading the skills of the workforce. “The retrofits were different than the facilities our staffs were trained in. It was critical that we update our standard operating procedures (SOPs) to ensure that we were addressing our employees’ safety concerns, the heat detection procedures, vaccination and treatment procedures and body condition scoring with feed adjustments to ensure we were providing proper care for the sows and litters,” Rademacher explains. 

Ease of Management

The bottom line for the Murphy-Brown West decision makers was that the free-access stall systems were easier to manage than the small pens or ESF. “Based on the internal and external research we reviewed, the impact on production with free-access stalls mirrored the production with gestation stalls,” Rademacher explains. “The initial cost of the free-access system is a little more expensive, as are some of the operating costs. We are now on pace to convert about 30,000 sow spaces/year and on track to meet our commitment to the Smithfield mandate.” Although the free-access system is being used in the western operations, to avoid dramatic reductions in sow inventory, some small pens are also being used within Murphy-Brown as an alternative method to fulfill the commitment for phasing out gestation stalls.

Arizona Experience

The timeline for moving sows from gestation stalls to pens was somewhat shorter for Arizona-based PFFJ (Pigs for Farmer John), LLC, the live-animal division of Hormel Foods. In November 2006, the state’s voters passed Proposition 204, which effectively bans the use of gestation stalls on Dec. 31, 2012.

PFFJ launched a six-month project in October 2011 to help guide the transition of five, 2,700-sow farms strategically located on five sections of land near Snowflake, AZ. All newly weaned pigs flow to nurseries, then finishers, on a same site.

Like their Murphy-Brown counterparts, PFFJ staff led by Farm Operations Manager Don Davidson, DVM, dug into the research data and toured sow farms in the United States and Europe.

Once the decision was made to convert to small pens, all breeding and gestation barns were systematically converted. Gestation barns contained 12 rows of 69 stalls (828 stalls) measuring 2 x 7 ft. They were retrofitted with gestation pens by removing four butt-to-butt stalls on each side of an alleyway to form 8 x 16-ft. pens to house eight sows (16 sq. ft./sow). The eight existing drop boxes were utilized for feeding. Swinging nipple waterers were installed vs. fence-mounted nipple drinkers to avoid injuries and lesions that often occur when sows fight in close quarters, Davidson explains.

In addition, they retrofitted Lubbock-style breeding barns with six rows of 80 stalls (23 in. x 7 ft.). The removal of four breeding stalls and the accompanying space behind them formed six rows of 20, 7 ft. 8 in. x 15 ft. pens. Four existing feed drop boxes and three additional drop boxes allowed them to feed and house seven sows per pen (16.44 sq. ft./sow). Water troughs were filled with concrete and swinging nipple waters were added.

“One of our goals was to maintain the same sow inventory to match existing nursery and finishing space,” Davidson says. “We were a little short on wean-to-finish space, so we built two new wean-to-finish barns, which we used to house sows during the retrofit. It took seven to 10 days to retrofit each barn, but we also took the opportunity to fix some things and replace and repair cracked slats.

“We thought the retrofitting would take longer. We have gotten through one full turn of complete (all) group housing, so we have 90 days of group housing to compare with 90 days of gestation stall housing from last summer,” he continues.

“With the retrofit, farrowing rate was depressed about 2%, we lost about 0.25 pigs total born/litter, and our sow mortality was 1.35% higher. That’s just a 90-day snapshot. It is still new to us, so we are still learning. The farm is managed a lot differently, so ongoing training is very important,” he notes.

To date, Davidson lists these advantages of the converted barns: “Sows have a lot better locomotion; they move a lot better. The barns are much more open and the noise levels are much lower, so the people like working in them.”

The disadvantages include: “There are a lot more scratches on the sows and more bites of the vulva. And it is important to recognize the disadvantaged sows immediately and get them out of the pen. It’s one of the big training objectives — when the farm staff drops the feed, they have to be walking along those pens and identifying those disadvantaged sows. We feed twice a day.

“There is a lot less space, so as we try to maintain the same sow inventory as we move sows to hospital pens and keep the pens static, space is becoming a factor.

“We also measure feed disappearance on a quarterly basis. In the first quarter, gestation pen feed is running about a half a pound more (per sow). There’s more feed going through the slats and into the alleyways,” he says.

“The sows seem to be comfortable and it looks like it is working,” he concludes. The cost of conversion was $85/total inventoried sow space, one of the least expensive options they studied.