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New Genetics Drive Gilt Replacement Program

High sow mortality and culling rates drove Illinois pork producers Jim and Steve Moest to the brink about a year ago. The Moest brothers had pleaded with their commercial seedstock supplier for nearly a decade to deal with the excessive sow dropout rates. PigChamp summaries for 2000 documented sow death losses in their 1,800-sow, High Plains herd at 12.7%, while the 1,400-sow, High View Pork herd

High sow mortality and culling rates drove Illinois pork producers Jim and Steve Moest to the brink about a year ago.

The Moest brothers had pleaded with their commercial seedstock supplier for nearly a decade to deal with the excessive sow dropout rates. PigChamp summaries for 2000 documented sow death losses in their 1,800-sow, High Plains herd at 12.7%, while the 1,400-sow, High View Pork herd recorded sow deaths at 10.2%. The High Plains farm was started in 1994 and the High View Pork operation began production in 1998.

“They'd stand right there and tell us that 10-12% mortality in sows is acceptable. It is not acceptable!” Steve emphasizes.

Sow culling rates topped out at 66% in the High Plains herd in 2000; the High View Pork herd peaked the following year at 62.8%.

Sow losses moderated slightly in subsequent years, slipping to between 6.4 and 8.1%, but by the fall of 2002, the Moest Brothers had had enough. They launched a plan to take control of the genetics inputs of their internal gilt multiplication program.

“We informed our gilt suppliers that if they would fix just a couple of the persistent problems, they would be in control of the industry,” explains Jim Moest, veterinarian and 10% owner of the pork operations.

Steve Moest gets more specific. “Part of the problem was mortality, but we also had a high turnover rate. By the time we got done with the bad feet and legs, the cripples and the deads, we were replacing 65-70% of the gilts and sows some years.”

Search for New Genetics

The Moests were not new to producing their own replacement gilts. Their former seedstock provider had supplied the grandparent females used to produce parent stock bred for commercial production.

To establish a new grandparent sow herd, they began a search for 300 purebred Yorkshire gilts that would serve as their genetic base. They found what they were looking for at Witzig Farms, Gridley, IL.

“We liked what we saw at the Witzigs. They had a lot of good STAGES data, good feet and leg soundness and other things we wanted,” explains Steve.

STAGES is the Swine Testing and Genetic Evaluation Systems program administered by the National Swine Registry in West Lafayette, IN. The program focuses on key performance traits (growth, backfat, pounds of carcass lean) and reproductive traits (number born alive and weaned, 21-day litter weights) used to calculate terminal sire, sow productivity and maternal line indices.

“We index the (purebred Yorkshire) sows monthly using the Herdsman program, and select the top 20% to breed back to purebred Yorkshire boars to maintain our nucleus herd,” explains Jim. “Currently, we have three purebred Yorkshire boars in the stud. We try to match up the type of boar with the type of sow that will make the most improvement.”

Two of the Yorkshire boars were selected for their maternal trait rankings in the STAGES program, and a third was home-raised.

Having settled on the maternal lines, they turned their attention to identifying sire lines that would complement their purebred females, which would be used to produce first-cross females to be used for market hog production. They turned to the nation's oldest purebred herd, Waldo Farms, DeWitt, NE, to supply half Duroc, half Landrace (D-L) boars mated to select Yorkshire females to produce parent females.

Parent females are bred to purebred Duroc boars to produce the nearly 45,000-50,000 market hogs the Moests produce annually.

Artificial insemination is used exclusively. The Moest boar stud houses 50 boars — four D-L boars, three purebred Yorkshires, and the remainder as purebred Durocs used for terminal market hog production.

Waldo Farms and Huinker Durocs, Ltd., Decorah, IA, supply the Duroc boars. They are responsible for selecting Duroc boars for production performance, meat quality and structural soundness.

“We pay a royalty for the semen we use,” Steve explains. “If we don't like a boar, we don't use him. If we don't use him, they don't get paid. They know it's in their best interest to send good quality boars.”

“If we actually owned these boars, we wouldn't turn them over as fast as they turn them over,” Jim adds. “They call us when they have a bunch of good, high-indexing boars, so we always have good, young boars.”

Screening Replacement Gilts

The most challenging part of the internal gilt multiplication program is finding the best possible parent gilts to serve in the commercial production herd. The job is not for the faint of heart. It requires additional labor, astute pig identification and recordkeeping and computerized ranking of candidate gilts.

Weighing pigs at birth was not new for the Moests. However, they take the additional, critical step of accurately identifying purebred and first-cross gilts needed to maintain the purebred nucleus herd as well as the best parent line sows for commercial market hog production.

The Moests use a double identification system of earnotching and tagging. “Our purebreds all get notched and tagged right away. The notch ties them back to their dam,” explains Steve. “The gilts in parent (line) litters are tagged when they are a day old. Blue tags are parent litters and orange tags are purebred Yorks, so they are easy to identify at weaning.” Litters are intermingled at weaning, so it is imperative to retain identification.

“When we bought the original 300 grandparent Yorks, we obtained the full pedigree and EPD (expected progeny difference — a measure of genetic merit) ranking, so that as we produce our own gilts, we have a full pedigree on gilts in the nucleus herd,” explains Jim. The pig identification serves as the link back to sow EPDs, he adds.

The first screening of candidate gilts occurs at the identification stage. Farrowing unit manager Lori Wendt counts teats and enters the number in the computer record.

The next screening comes when gilts leave the nursery. Problem gilts are removed and sent to finishing barns; 90% of pure and first-cross gilts are sent to gilt development barns.

As gilts average 240-250 lb., the Moests do a walk-through screening and mark obvious culls before ultrasound scanning technician Dallas McDermott, Harlan, IA, arrives to measure loineye area and backfat depth.

Individual identification, weight and scan measurements (backfat and loineye area) are recorded immediately into a laptop computer. Groups of 175-225 gilts are weighed and scanned in 4-5 hours with two people sorting and running gilts into the scale — one reading identification tags and releasing the gilts from the scale, another entering data on the laptop.

Feet and leg soundness and skeletal structure and underline screening are done during scanning. Farrowing house manager Wendt runs the release gate and has the prerogative of culling any gilt with a temperament she thinks will be a problem in the farrowing house.

After scanning, gilts are ranked using the Herdsman maternal index from S&S Programming, Inc., Lafayette, IN ( The index includes EPDs for days to 250 lb., backfat depth, loineye area and lean gain/day, number born alive, litter birth weight and number weaned, and weaning weight. The Moests converted their PigChamp data to the Herdsman program so gilts can be indexed and ranked for their genetic merit.

Accurate identification also provides links from the electronic farrowing records to their actual sire, dam and birth records. The combination of genetic heritage and individual performance and scan data are used to calculate a maternal index and rank the candidate gilts from best to worst.

Table 1. Contemporary Group Gilt Attrition and Production Costs
Gilts entered 258
Died 1
Culled before scanning 32

Numbers scanned 225
Culled after scanning 59

Entered herd 166
Percent selected 64.34
Gilt Production Costs
Start weight, lb. 17,400
Ending weight, lb. 61,336
Total gain, lb. 43,936
Feed consumption 132,134
Feed:Gain 3.01
Feed cost $9,430.52
Feed cost/pig $36.69
Gilt Production (Cost/pig)
Feeder pig cost $43.00
Feed cost (67-238 lb.) $36.69
Building cost $13.32
Increased semen costs $4.35
Labor - scanning $2.18
recordkeeping $2.50
Scan fee $3.00
Breeding stock depreciation $8.33

Total 113.37
Assumptions: labor — three employees for 5.5 hours at $12/hr.; semen: 360 doses York at $9.50/dose (grandparent/purebreds), 1,440 doses D=L at $3.50/dose (parent/Firstcross)

The number of gilts retained for breeding depends on the need for replacements. Normally, at least the bottom 20% are culled.

In a recent group of 258 gilts placed in the gilt development unit, one died and 32 were culled for various reasons; 225 were scanned; and 59 were culled after scanning, leaving 166 (64.34%) to move to the breeding herd (See Table 1).

With all costs accounted for, gilts from this group cost $113.37 to produce. “That's considerably less than the $80 over market price we were paying our previous supplier,” Jim states.

Results and Lessons Learned

The Moests currently have about two-thirds of both herds stocked with the new genetics. The Herdsman program provides comparisons to previous production levels and helps track their progress.

“Our sow death loss has dropped,” notes Jim. “The highest we had in the High View herd was 10.2%, which is now down to 3.5%. The High Plains Pork herd has not been as dramatic.”

“Before, it was nothing to have 3-4 downer sows all the time,” says Steve. “That's really tough on employees.”

“We're still learning how to manage these animals,” Jim explains. “We've been scanning them too late, so some gilts have more condition than they should. Our number born alive (9.9 at Highview, 10 at High Plains Pork) is still not up to where it was before we made the change, but I think we'll get there.”

The Moests have been able to consistently deliver market hogs at 53-54% lean, while increasing marketing weights to about 285 lb. “I wouldn't say the quality is so much better than our previous genetics,” notes Steve. “But before, our (market hog) death loss was 5%, plus 10% culls (downers, tail bites, etc.). Now we're down around 2% death loss pretty consistently, and we attribute much of that improvement to better animal temperament. The first seven months of 2004, we lost only 17 pigs out of the 25,000 head transported,” he adds.

A few other things they learned:

  • Identification is critical. Poor-quality earnotching made it difficult to identify gilts. That was solved when the farrowing staff was brought in to read earnotches when gilts were scanned. “Now they understand why it's so important to get quality notches in those animals,” adds Jim.

  • Breeding to maintain grandparent and parent lines was simplified by dying boar semen red or blue to ensure proper matings.

  • More paperwork and labor are required to keep track of, scan and rank candidate gilts. “Someone has to be dedicated to overseeing the breeding program,” says Steve. Production manager Cathy Richardson handles that responsibility. “She keeps the matings straight and on track; she instituted the semen color-coding system so the inseminators get the proper matings. And, she inputs all the data, cleans up any anomalies and misidentifications, and oversees all pure Yorkshire matings. Things run a lot smoother with her around,” he adds.

  • There is better payback. Steve estimates a $1/pig produced advantage with their current program.

  • A new nucleus site will centralize gilt production. Recently, the Moests made another major commitment to their genetic program by purchasing a 1,400-sow, former nucleus herd site from a commercial genetic supplier. All gilt multiplication will move to this site, which features a nine-room, 1,800-head finisher. Steve describes it as “perfect for our gilt rearing and conditioning program.” They will stock the unit with 450 pure Yorkshire nucleus females, and the balance will be filled with commercial sows. “Now all of our gilt growing and scanning will be accomplished in a centralized building,” he adds.

  • Raising pigs has become more interesting. “It actually brought some of the fun back into raising pigs,” explains Steve. “We always enjoyed the genetic aspect of pig production. Before, we would get frustrated when we got some of the stock. Now, we can go out and find what we want. If we want to switch to another breed, we can make that switch tomorrow.”

Steve is in charge of managing the hog operation. He and his wife own 90% of the corporation. Jim also has a veterinary clinic commitment to spend every Wednesday in the hog operation.

Certified Ultrasound Technicians

Dallas McDermott, owner of Mac Scan ultrasound services, Harlan, IA, scans roughly 25,000 hogs annually. He has 4-5 regular commercial producer and about 20 purebred seedstock supplier clients. He also works some county and state fairs. Standard fees range from $3-$8/head, depending on the group size and location. In some circumstances, McDermott charges a flat fee for the day.

“The thing I like about the Moests' approach is that they use a combination of performance data and visual appraisal to select their replacement gilts,” McDermott says. “They're combining the art and the science of breeding hogs.”

McDermott is one of 26 ultrasound technicians certified by the National Swine Improvement Federation (NSIF). The federation has implemented programs to standardize ultrasound measurement of backfat and loineye area. Technicians must attend a workshop, training session and scanning practicum, and take a written exam. Participants are evaluated on their ability to predict carcass measurements, the repeatability of their measurements, and bias of live measurements compared to actual carcass data. Those who meet minimum standards of accuracy are certified for their ability to accurately measure backfat, loineye area or both. A complete list of Certified Ultrasound Technicians can be found on the federation's Web site,

TAGS: Reproduction