The Carroll family of Carthage, Il, recently started production in this new wean-to-finish barn with 100-head pens.

When the Carroll family of Carthage, IL, heard about potential square footage savings by using big pens in their new wean-to-finish barns, they were intrigued. "it was kind o-finish interesting idea," says Dan Carroll, who raises hogs with his brother, David and father, Darel.

By designing pens to accommodate 100 pigs, the Carrolls figure they can load buildings at 6.5 sq. ft. per pig versus the traditional 7.5 sq. ft. Besides, with death loss and some routine sorting, Dan estimates space allocations will be closer to 6.8 or 6.9 sq. ft. by the time pigs near finishing.

This past March the Carrolls filled the first of four new 1,200-head wean-to-finish buildings. The buildings are tunnel ventilated, with gas infrared overhead heating tubes, concrete slats and separate feeding systems for split sex feeding. The buildings have center walkways with six, 100-head pens on each side.

A swing gate is installed at the front of the pens to aid in catching and sorting pigs. "The pigs do learn to run in the large pens," says Dan. "You have to have some stick-to-itness when you are trying to catch them, but one person can do it."

A single, five-hole Farmweld Jumbo Feeder is located at the center of each pen creating an island that pigs can access from both sides of the feeder. The large pen size lowers the budget for feeders slightly since single five-hole feeder handles 100 pigs, whereas two three-hole feeders are needed to accommodate that number in 25-head pens.

David Carroll says that the little pigs adjust well to the big feeders. "A lot of times you come into the barn to see two or three pigs eating from the same hole," he says.

A five-foot sect ion of gating is attached to each feeder to hold four Farmweld DRIK-O-MAT® Water Cups, mounted back-to-back, four inches from the ground. Dan says pigs weaned into the new facilities "have had no problems with the big cups." He observes, "They walk all around the pen and check it out and they find the drinkers right away." The Carrolls say they are also impressed with the data showing that the DRIK-O-MAT cups waste a lot less water than other drinker options.

Dr. James Lowe, a veterinarian at the Carthage Veterinary Service who works with the Carroll family, says there is not yet data from which to draw firm conclusions about big pens in wean-to-finish barns. However, he says, there is evidence that large pen size may reduce end weight variation.

"At feeder pig weight, we know the weight spread between the lightest and the heaviest pigs is tighter in big pens," says Lowe. "If we can make the group more uniform, it may not improve average performance, but we'll have fewer pre-markets and more (productive) days per turn."

He suggests the improvement stems from the pigs' natural behavior and the social effects of larger groups. "Pigs probably get along best in groups of six to eight," contends Lowe, basing his opinion on research conducted by animal behavior experts. "In a group of 25, they can figure out who everyone else is." In other words, they can identify their place in the pecking order. "If you take one out, then you upset the social order," says Lowe.

On the other hand, if you have a group of' 100 pigs, there may be 20 social groups of four to six members. "if you pull one out, then you affect five pigs, but not the other 95," Lowe explains. "In a group of 25, if you pull one out, you'll affect the other 24." Consequently, Lowe says, pigs may get stressed, slip in feed intake and experience a lag in growth.

Pigs in larger pens seem
to be more organized for
sleeping, eating and dunging.

Pigs in larger pens seem to be more organized about how they zone their pens for sleeping, eating and dunging, according to Lowe. "Because there is more space, they can physically separate and there is less confusion," he says.

By putting in the larger pens in their new wean-to-finish barns, the Carrolls estimate they trimmed about $4 per pig space off their total building costs. "If it is true that you can use less square footage per pig in large pens, that would save an additional $10-13 per pig space," notes Dan.

The Carrolls say it will be a couple of years before they'll know whether the 100-pig pens have any negative effects on performance. They say that if they see any problems, they left themselves an out. "We can always add gating to make smaller pens," says Dan. For now, "we are going to see how this works out."