It took the harsh Minnesota winter of 1996-97 to convince Lynn Becker that something had to be done about the poor performance in the family corporation's pig nurseries.

Pigs in three, continuous-flow nursery facilities were hit with a bout of respiratory problems that forced depopulation of the barns.

Becker wanted to bypass the nursery phase altogether and wean directly into two new, large-pen finishing barns the family had just completed. He'd heard several positive reports from farms in southeast Iowa about the advantages of wean-to-finish production systems.

The Beckers followed Lynn's advice. The farm corporation, located near Fairmont, MN, includes Lynn, his parents, Larry and Linda, and brother Lonny.

Today LB Pork Inc. weans 18-day-old pigs twice a week into 26, 600-head, wean-to-finish barns and two, 200-head barns. LB Pork owns half of those facilities, the other half are contract production.

Building Features 'These are all standard, double-curtain-sided finishing barns with a few modifications,' explains Lynn Becker. Features include concrete slats, Farmweld jumbo feeders and Edstrom water pans.

Feeders and water pans are set on a 31/2-in.-high raised pad of concrete in the center of the pens. Some of the finishers have center alleys, others north or south side alleys.

During the first 2-3 weeks the newly weaned pigs are in the finishers, they are pampered with radiant heaters and recycled rubber floor mats to create a comfort zone. For the first few days, pigs are given pelleted feed on the concrete pads as well as in the feeder. Nipples are allowed to drip until water pans are full for the first 5-6 days to help the pigs find the water source.

Large Pens Pigs get an average of about 7 sq. ft. of space during their stay from 12 lb. to 250-260 lb. in large pens holding 100 or 150 head. The Beckers remodeled half of their barns, including the nurseries, to wean-to-finish. Five finishers have pens holding 150 head. Most all of the rest hold 100 head.

Becker has preferred large pens since he tried them in the nursery. 'We remodeled into large pen nurseries in the summer of '96 to mid-'97 and we just loved how those large pens worked as far as labor efficiency and the ease with which you can create warm zones with the mass of pigs,' he points out.

'We had a barn where the main heater went out during a terrible snowstorm in the dead of winter. Because we still had LP, the radiant heaters kept going. My brother said the temperature under that heater was a comfortable 75-80 degrees F., while the rest of the barn was 45-50 degrees . Pigs were piled three to four deep when he got in there. Pigs came out of it with a little cough, that was it, because they crammed into their little warm zone andbasically lived in there until we got the heat back on,' Becker relates.

In the wean-to-finish buildings, defined living zones have been created by the large pen concept. The heater and comfort mat have established the front part of the pen as the 'bedroom.' The middle section with feed and water is the 'kitchen,' and the back, cooler part of the pen is the dunging area or 'bathroom.'

These defined areas have helped reduce social problems, he says. Simply because of the larger area, pigs can usually avoid fights in the large pens by moving to another part of the 37 x 20-ft., 100-head pens. The 150-head pens are 60 x 18 ft.

Other industry observers suggest there are fewer problems in large pens because there are so many penmates that a social structure is never really established.

Don't Complicate Things At weaning, pigs are sorted by sex into an equal number of wean-to-finish pens. Employees once tried to closely sort by size also, but this proved to be less efficient, says Becker. The mid-size 'boss pigs' all ended up in the same pen. Growth of small and large pigs, in their own respective pens, was not very good. Maximum growth seems to be with normal grouping and social order.

In Becker's view, here are a few other wean-to-finish management ideas that are less efficient:

* Don't section off pens. 'Some people like to section off half of the pen when they first try large, wean-to-finish pens. That's an extra gate you've got to have in there, more cost and more work. We wean young pigs in there and they use the whole pen.'

* Avoid double filling. 'We have had to do some double filling. We have found when we move some of those pigs out, performance is worse in both groups, the pigs that stay and the pigs that move out when we go back to single fill. It must be stress because when we have done that it produces worse health challenges and worse close-outs,' says Becker.

Becker's point is simple. Don't complicate wean-to-finish. Stick to the single production move from farrow-to-wean-to-finish and you will save a ton on labor. He figures in LB Pork's 1,200-sow operation the total switch to wean-to-finish production will save roughly 250,000 gal. of water annually and require 52 fewer days of pressure washing.

Less manure dilution should add greatly to the quality of manure being applied onto cropland, he notes.

And the improvement in pig flow from one move translates into 10 less days of downtime per barn per year, he says, with a lot less hassle of moving and washing between groups.

Animal Health Past, Present Adding to health problems in the past was the fact it took two weeks, and often twice that long, to fill the nurseries. Today it takes an average of eight days to fill a 600-head, wean-to-finish barn. That greatly reduces age spread and the potpourri of respiratory problems that used to plague the farrow-to-finish operation. 'We've never had pigs this healthy up to 150 lb.,' says Becker.

But then problems have set in for the operation. More than a year after the first new, wean-to-finish units were built, another respiratory foe has emerged in the form of Porcine Respiratory Disease Complex (PRDC).

Becker says serology testing has shown that Mycoplasmal pneumonia is setting up 150-lb. hogs for Porcine Reproductive and Respiratory Syndrome (PRRS) problems. 'It's the 18-week wall that everyone is talking about,' he says.

But he is optimistic that the treatment programs being put into place will soon get the disease complex under control and performance will rebound.

Why does pig performance seem to soar in wean-to-finish barns?

Paul Ruen, DVM, Fairmont Veterinary Clinic, Fairmont, MN, sees 11 key reasons for the success:

1. Forced all-in, all-out pig flow. Pigs are no longer being sent into nurseries on a continuous-flow basis.

2. Multi-site production has provided more space options for a wider range of sow herd sizes.

3. Feeders used in wean-to-finish units are superior to those used in existing nurseries.

4. Budget feeding is more accurate.

5. Water is more available and managed better.

6. Space needs of nursery pigs were underestimated in the past.

7. Less 'downtime' (days).

8. Group integrity is maintained with no mixing and disruption of social order.

9. It's easier to create eating, sleeping, dunging zones.

10. Workers are happier because less time is spent washing, moving and treating pigs.

11. Producers seem to be more conscientious and keep more accurate records.

Cost Matters Standard wean-to-finish facilities (not large pen design) with zone heating, comfort mats, etc., will likely cost $5-10/pig space more to construct than a standard finisher, says Ruen.

Assuming there are an equal number of pig spaces for nursery and finishing as in wean-to-finish, it would cost $30/pig space to convert the whole farm.

Amortized at 10 years and 10% interest, that figure becomes $5.50/pig space, about $2.25/pig marketed.

Some of this cost can be recovered by fewer culls (82 cents/pig) and deads (97 cents/pig). Better average daily gain will mean $3.66/pig more gross profit. Add in labor savings of 90 cents/pig, there will be $3.95 extra profit for each market hog sold, according to Ruen. He says that figure includes no improved performance in feed-to-gain ratio nor use of any double-filling barns at weaning.

There are many reasons why wean-to-finish barns have proven so profitable for a variety of sizes and types of hog operations, observes Ruen.

'Because these barns can always be used for finishing, at the very least wean-to-finish barns offer a low-risk option for farms that wish to target pig flow changes for health or management reasons,' he says.

Still, many operations with conventional nursery and finishing systems can achieve similar success by adopting a wean-to-finish thought process, concludes Ruen.