National Hog Farmer is part of the Informa Markets Division of Informa PLC

This site is operated by a business or businesses owned by Informa PLC and all copyright resides with them. Informa PLC's registered office is 5 Howick Place, London SW1P 1WG. Registered in England and Wales. Number 8860726.


Articles from 2005 In January

Focus on Risk Management

The years 1998-2000 taught this Iowa producer-veterinarian that risk management must be a top priority, even when prices are very good.

It would be easy for pork producers to get complacent when hog prices have been good for a stretch.

“Certainly, these (late 2004) prices are uncharted. We haven't seen profits of this magnitude for many years,” says 47-year-old Craig Rowles, DVM.

Rowles worked at the Carroll, IA, veterinary clinic for several years, then formed a partnership in 1996 to start Elite Pork Partnership, a 5,000-sow, farrow-to-finish operation near Carroll.

He understands the pent-up demand for new farm and hog equipment.

Some replacements are needed, but he cautions: “I would hope that everyone remembers the pain of '98-'00. And, I hope the lenders remember that pain as well, because we are our own worst enemies in terms of wanting to expand production once we make profits.”

Lead by Example

For his part, Rowles hopes to lead by example. He wants the 28 employees of Elite Pork to see that he didn't run right out and buy a new pickup, for instance. Instead, he traded his six-year-old truck for a four-year-old truck.

“The example I want to set for my employees is that just because we are making big money doesn't mean I am going to go out and buy a brand new truck — I am watching the money,” he says.

And Rowles vows he's not planning a big expansion of his operation in response to the price spikes of 2004. He is in the process of adding an additional farrowing room to existing facilities, not to add sows, but to move from an 18-day weaning age to a 22-day weaning age.

“It is our major project for us this year, but we can afford to do it because we are making some money,” he stresses.

Adding farrowing crates does add to costs, but it provides a measurable payback. Weaning later improves throughput, breedback and sow longevity, and is virtually guaranteed to lower production costs, Rowles stresses.

Making money by lowering costs is the goal he has set for the closely managed operation. His November and year-to-date production costs were precisely $39.09 and $40.37, respectively, and that number was falling rapidly as feed costs continued their decline with the record harvest. Eventually, he predicts production costs will need to reach the mid-$30s to survive in the pork industry.

Watching Costs

Especially for smaller, independent producers, the first step is ensuring costs are being measured — and measured accurately, says Rowles. Independent producers often have several different enterprises in the farming business, and they need to separate those enterprises for billing purposes, particularly grain production from hog production.

Once costs are measured, they can be evaluated and benchmarked against different production systems. This can be done using your veterinarian, consultant or accountant.

“In our case, when we went through that 1998 to 2000 phase, we really went through a heavy analysis of every single item that went into our business, and tried to measure what was giving us a clear, consistent and measurable return. That is the standard by which we tried to evaluate everything that we were doing,” Rowles states. “And if we couldn't measure a clear, consistent and measurable return, then we didn't keep it.”

Cost-cutting measures included:

  • Reduced reliance on vaccines.

  • Reduced use of antibiotics and discontinued use of growth-promotant antibiotics.

  • Monitored diet inputs to provide the best-cost formulation within feed budgets.

  • Planned annual purchases of energy needs to optimize costs and supplies.

  • Utilized an outside trucking firm for hauling hogs and feed.

  • Switched to an internal gilt multiplication breeding program. “We have reduced our costs by going to internal multiplication. The other reason we went to it was biosecurity. In fact, biosecurity is probably more important because it reduces our costs by reducing the disease outbreaks.”

    Rowles simply got tired of bringing in a new bug every time he introduced breeding stock. “We just kept running through this cycle of PRRS (porcine reproductive and respiratory syndrome) outbreaks, and I finally just threw up my hands. Since we went to internal multiplication a couple of years ago, the health of our operation has stabilized,” he says.

  • Instituted flexible risk management strategies to provide market price protection (for inputs), while hedging about 50% of production to capture profitable market swings during high-risk months.

Controlling Neonatal Diarrhea

Neonatal diarrhea has many causes. Transmissible gastroenteritis (TGE) occurs sporadically and coccidiosis appears seasonally, but the most commonly seen diarrhea is colibacillosis or Escherichia coli (E. coli).

The conditions caused by colibacillosis are an acute, sometimes fatal enteritis of suckling pigs. The disease spreads rapidly within a litter and is easily spread within the farrowing area by equipment, hands and boots.

The syndrome has three clinical parts: septicemia (infection of the bloodstream), diarrhea and edema disease. The first two are most commonly seen in preweaning pigs.

E. coli organisms are present everywhere in the environment. The young pig acquires the bacteria orally from contaminated surfaces: the sows' udder, teats and rear quarters, fecal material, pen walls, etc.

Primary septicemia and diarrhea develop if the pig swallows an infective dose prior to receiving colostrum.

The syndrome can also occur if colostrum contains low antibody levels to infection or pigs have ingested a low amount of protective colostrum. After ingestion the organisms travel to the small intestine, multiply, produce toxin and trigger diarrhea. Death is due to dehydration, weight loss and inability to absorb fluids and nutrients.

Diagnosis is confirmed by culturing the small intestine and recovering the organism. Other diarrheal diseases of the newborn pig that must be differentiated are TGE, rotavirus, clostridium and coccidiosis.

Case Study No. 1

A 350-sow, farrow-to-finish, one-site farm experienced a sudden “outbreak” of E. coli in farrowing. Diarrhea was also occurring in newly weaned nursery pigs. Rectal swabs, euthanized pigs and tissues were collected. Laboratory tests verified E. coli.

In reviewing farm procedures, it was discovered that several changes had occurred. First, the power washer had not worked for several weeks so farrowing and nursery rooms had not been cleaned. Second, a new staff person was working in the farrowing area; and third, the prefarrow exposure program had been abandoned when the previous staff person quit.

Deficiencies were corrected. The power washer was repaired. Affected farrowed pigs were given injectable antibiotics. Nursery pigs were placed on water medications. There was good response to treatment. Preventive medications were used for two weeks. The farm farrows and weans weekly.

As part of the improvements, internal biosecurity procedures were reviewed and reinstituted. Staff were trained to properly wash and disinfect farrowing and nursery rooms, wash hands and boots frequently and watch the traffic patterns within the unit hallways. The hallways and feed carts (used for transport of pigs) were also cleaned to reduce tracking of contaminated material.

Also, the farrowing staff person began an intense effort to scrape fecal material out of all farrowing crates daily. This material was fed back to sows 3-6 weeks prefarrowing to provide exposure to the E. coli that had occurred in farrowing.

Within four weeks of the first clinical signs, scouring in newborn pigs stopped as did postweaning diarrhea.

Case Study No. 2

This farm is 180 sows housed in batches in outdoor groups. Farrowing, nursery and finisher buildings are all on one site but in separate facilities.

The producer indicated there was an increased level of scours in gilt litters. Some entire litters were affected. A few affected pigs were euthanized and tissues collected. The lab confirmed hemolytic E. coli.

At first, affected litters were treated with antibiotics. Treatment response was variable and the producer didn't want the hassle of treating pigs.

Further investigation revealed why gilt litters were more affected by diarrhea. Gilts were kept in a yard and confined during gestation. Gilts farrowed smaller litters and “extra” pigs were transferred to them for suckling. In these litters with crossfostered pigs, the transferred pigs would show diarrhea, while pigs that remained in their original sow litters didn't develop diarrhea.

Further review revealed manure feedback was done regularly for sows prefarrowing, but not to gilts. Part of the reason was that gilts were housed in a partially slotted floor building on self-feeders. It was decided the best solution was to vaccinate gilts. The first batch of vaccinated gilts farrowed without litters showing diarrhea and that practice continues today.


E. coli organisms are spread by rodents, contaminated feed or equipment and personnel. Reduce exposure by keeping equipment clean and washing hands and boots.

Contact your veterinarian when clinical disease occurs to get a complete diagnosis. Use your herd health advisor to evaluate your system. Periodically review farm processes to reduce chances of a “breakdown.”

Pork Exports Break Another Record

U.S. pork exports have broken the record set in 2003 — even though data has only been compiled through October 2004, according to the U.S. Meat Export Federation (MEF).

For January-October 2004, pork exports (including variety meats) rose 34% in volume to 901,960 tons (Figure 1) compared to the same period in 2003, and were 38% higher in value at $1.582 billion.

Pork exports to Japan were 12% higher in volume at 284,529 tons and 20% higher in value at $813.2 million, compared to the first 10 months of 2003.

However, Mexico recorded its fifth-consecutive record year of U.S. pork imports to retain its ranking as the number one destination for U.S. pork exports. For the first 10 months of 2004, pork exports to Mexico reached 314,725 tons, more than 73,700 tons above the whole of 2003. The value of U.S. pork exports to Mexico also set a new record at $445.7 million, compared to $294.9 million for all of 2003.

U.S. pork exports for 2004 are also expected to break records for exports to Canada, China and Taiwan.

Animal Care and Handling Conference

The American Meat Institute Foundation Animal Care and Handling Conference is Feb. 9-10, 2005 at the Marriott Downtown in Kansas City, MO.

The popular conference will feature three tracks: management and policy, cattle handling and pig handling. Also included are two pre-conference workshops on the National Pork Board's Trucker Quality Assurance program and a Cattle Transport Workshop hosted by Calico Consulting.

To register, contact conference coordinator Katie Brannan at (202) 587-4223 or, or register online at

Versatile Landscraper

The Westendorf Landscraper can be used for forming and maintaining drainage ditches, constructing terraces, removing snow or spreading rock and gravel. It is available in 8- 10- or 12-ft. models and has a 6-in.-high carbon steel cutting edge and hubs/bearings that are interchangeable with Westendorf's standard WW-1610 wagon. Grease zerks are located at all pivot points and a gauge rod shows the cutting depth. The Landscraper also has a 3-in. lift cylinder, 15-in. standard rims and an extra strong tongue constructed of square tubular steel. The large weight box provides additional cutting pressure needed for more challenging tasks. The new system allows each wheel to be adjusted independently to provide 0-12-in. tilt of the cutting bar by using a manual crank or the optional hydraulic cylinder.
(Circle Reply Card No. 101)

New Feed Handling Software

Easy Automation Inc. introduces its new Feed Office Pro software, which builds upon earlier Easy Feed and Quick Feed software packages. The system is designed with numerous modules that allow the package to fit the needs of medium- to large-farm feed-milling systems. Features include the ability to store rations, perform the company's patented automatic feed budgeting, manage and schedule feed orders, print delivery tickets, update rations from nutrition packages, manage inventory, manage animal groups, print mix tickets, price and cost feed, predict ingredient needs and more. The system is designed to link with many popular accounting systems. The single, expandable, multi-user system is simple to use, with typical implementations taking only a few days.
(Circle Reply Card No. 102)

Automatic Gate Openers

GTO Inc.'s Mighty Mule E-Z swing gate opener offers an affordable way to automate gates. The Mighty Mule runs on a low-voltage battery that's constantly recharged, so operation is not interrupted by a power outage. The opener operates with the use of a transmitter similar to a garage door opener and features a new soft start/soft stop feature. A solar panel to charge the battery is also an option for those who have a gate far from a power supply. The automated gate also features push-button programming and a larger control box with room for an additional battery.
(Circle Reply Card No. 103)

Welding Generator

The Bobcat 250 is the new welding generator from Miller Electric Manufacturing Company. The generator is designed for superior durability, strong generator power, quieter operation and better welding performance. It features a fully enclosed case, super-tough Xenoy “protective armor” on the front pane, an Accu-rated 10,000 watts of useable peak generator power and a 12 gal. fuel tank, which allows an additional four hours of work before refueling on a typical welding job. Under a continuous load of 4,000 watts of generator power, the Bobcat 250 can run for about 14 hours. In addition, Miller's new and exclusive Tri-Cor technology adds more iron to the stabilizer, improving stick-welding performance.
(Circle Reply Card No. 104)

New Utility Tractor Line

McCormick International USA has further enhanced the McCormick tractor line by adding the all-new C-Max Series, a new range of utility tractors that meets the requirements of price-conscious and small acreage owners. The C-Max Series features five models ranging from 59-99 engine hp (52-99 PTO hp) that utilize the latest generation of 3- and 4-cylinder Perkins 1100 Series engines. The tractors have three transmission options — 12+12, 24+12 with creep, and 24+12 with overdrive. All tractors feature a dry-clutch synchronized shuttle to ensure easy operation of directional change.
(Circle Reply Card No. 105)

Low-Profile 400 Series Tractors

AGCO Corporation's Massey Ferguson 400 Series tractor line is now more versatile with the introduction of four new low-profile models. The tractors are lower and more compact all around to fit into tight, restricted heights. Design changes, such as the reengineered rollover protective structures (ROPS), redesigned fenders and even the downsized steering wheel, shave inches off tractor height. Smaller diameter wheel offerings not only shorten the profile, but also lower the center of gravity. Two four-position hydraulic valves, with kickout and float as standard equipment, make the tractors more responsive.
(Circle Reply Card No. 106)

Cab-Forward (CF) Trucks

International Truck and Engine Corporation will begin production of the versatile CF Series in early 2005. Providing maneuverability in an economical package, the CF series features the new International VT 275 V6 diesel engine and a high-strength, low-alloy steel frame with 34-in.-wide frame rails, taper-leaf suspension and standard front-and-rear shock absorbers. Two models are available: the International CF 500 that targets the Class 4 market with a 16,000-lb. GVW rating, and the International CF 600 for the Class 5 market with a 19,500-lb. GVW rating.
(Circle Reply Card No. 107)

Send product news submissions to Dale Miller, Editor(952) 851-4661;

Farrow-to-Wean Business Booms

A southern Iowa business is rapidly becoming a major supplier of quality weaned pigs to meet growing customer demands.

The continuing exodus of sows from the United States' breeding herd has left a number of independent finishers desperate to find a source of pigs.

For the past few years, Canadian interests, plus a steady influx of weaners and feeders into the eastern Cornbelt from North Carolina, have captured a fair chunk of that business.

U.S. Company Enters Picture

With little fanfare, one company is working to fill the void of U.S. suppliers by producing large groups of high-health, weaned pigs to feed out across the hog belt.

Natural Pork Production (NPP) II of Harlan, IA, owns and operates five sow units boasting more than 20,000 sows in Iowa, about 10,000 in Indiana and a few thousand in Minnesota.

Somewhat unique in the hog industry, NPP II's sow units are only built (or acquired) when it is determined that there is an adequate customer base to secure a buyer for virtually all the pigs. Buyers sign seven-year contracts guaranteeing they will receive a set number of pigs at a flat price, according to managing partner Gary Weihs.

Contract Pricing

Prices are set competitively and based on the principle that there is a $10 profit per market hog (based on averages over time) in the farrow-to-finish model. Weihs figures there is about a 40-60 split in capital, with 40% belonging to the farrow-to-wean sector and the remaining 60% used for wean-to-finish production. “So if there is $10 profit in a finished pig, we will take $4, the customer can have $6 and we should all make money,” he explains.

Weihs continues: “We flat price everything so that we make a little bit per head and base our profits on quantity; (we) leave the lion's share of the profits for the finishers because they are our customers, and we want to ensure that they can make enough money to stay in business.”

Currently, NPP II supplies about 15 independent pork producers with close to 800,000 weaned pigs to fill mainly 1,000-head barns in Iowa, Indiana and Minnesota.

Partner Mark Zaccone says demand is strong for the pigs, but not just anybody can sign a long-term contract with NPP II. Financial background checks are done on each potential buyer.

“If they don't have the wherewithal to withstand a seven-year contract, they need to have someone back them should there be trouble, thus reducing revenue risk,” he notes.

“The whole goal of this is to take as much risk out of this as we can, and it has been extremely successful. We still carry the health risk with the sow unit and that is enough,” adds Weihs.

Returning to Raise Pigs

After an absence of 24 years while working in a variety of executive business positions outside Iowa, Weihs, a civil engineer by education and operations manager by trade, returned to his native state in 1998 to start NPP.

“Our objective was to move back to Iowa because we had lived in 10 different states. Frankly, moving around is not all that it's cracked up to be,” says Weihs.

In 1998, he built the first of two, approximately 5,000-sow units in rural Harlan, IA, less than two miles from where he grew up on a 60-sow operation.

The second sow site was built in 2000. The family's home overlooks both sow sites, and the company's office is located over their garage.

Other Iowa sow sites were added two miles west of Brayton in 2002, and near Estherville and Burt in 2003.

In the past year or so, NPP II has purchased an existing Austin, MN, operation of around 2,400 sows, and purchased, renovated and converted a farrow-to-finish operation to about a 10,000-sow, farrow-to-wean operation at Crawfordsville, IN.

Weihs says NPP II's rapid growth in just six years has all been due simply to growing demand in the weaned pig business. “We saw a need from customers who wanted to buy large groups of healthy, weaned pigs and thought we could fill that need.”

A few years back, all producers wanted was a 14-day-old pig, he recalls. Now he says the industry has learned these pigs are not as profitable as older-weaned pigs. The biggest sellers now are 21-day-old, 15-lb. pigs.

In providing weaned pigs, Weihs and his partners are dedicated to helping restore the sow base to Iowa and providing agricultural jobs for its citizens. He points to the fact that last year Iowa imported 14.2 million pigs, including weaners and feeder pigs.

“The farrowing business peaked out in 1968 when there was a little over 2.5 million sows in Iowa,” Weihs recalls.

“Last year, Iowa fell below one million sows for the first time. More than 60% of that industry is gone, and that's a lot of jobs. For example, each 5,000-sow unit will employ 16 people.”


The partners in NPP II include Gary and Diane Weihs, Mark and Kim Zaccone, Ron Beach and Mona Jones and Tom Zaccone. They partner with a local company, AMVC Swine Management Services in Audubon, IA, to oversee the design, planning and management of the pork operation.

In addition, they work with a related farming company that contracts application of plant nutrients to area fields.

In the organizational structure, the staff at NPP II and AMVC “take great pains to articulate the company's vision and strategy to everybody,” explains Gary Weihs. The key is to empower staff to perform at the highest level and stay customer-focused.

Goals are set and performance is rewarded with incentives and bonuses. A traveling trophy is awarded quarterly to the top-producing sow unit in the system, he explains.

Employees are empowered to achieve superior production by ensuring that all levels of the system have access to all pertinent performance data — and the process really works, attests Weihs.

For instance, most sow units are hitting the mark on targeted pigs weaned/ sow of about 9½ pigs or higher, and the pigs weaned/mated female/year target in the low to mid-20s.

The day-to-day management of the pork business, including personnel, is overseen by the Audubon-Manning Veterinary Clinic (AMVC), Audubon, IA. The clinic provides expertise in production and health management and is led by Daryl Olsen, DVM, and Steve Schmitz, DVM.

Herd Health Program

A key to the AMVC health program is bringing in gilts as weaned pigs from off-site, isolated gilt pool barns, says Weihs. Cull sows are run through the gilt development site to acclimate young gilts to any disease agents in the system, so they can achieve immunity by the time they enter the system to be bred naturally.

All sows are bred by artificial insemination using semen screened by polymerase chain reaction for PRRS (porcine reproductive and respiratory syndrome).

AMVC has used herd rollovers to take some NPP II sow herds negative for PRRS, says Weihs. If a sow unit breaks with PRRS, serum therapy is used. The farm strain of the virus is collected and cultured to create a “serum vaccine” that is injected into all animals on that site, including all developing gilts planned for introduction to that site. This procedure has worked well to gain control of the virus, and has enabled the unit to provide PRRS non-viremic pigs to the customer again 8-10 weeks after a break. (For more details on “serum vaccines,” read “Controversial PRRS Control Procedure Wins Advocates,” pages 20-22, June 15, 2004 issue of National Hog Farmer).

Less than half of NPP II's sow units remain positive for PRRS, says Weihs. The ultimate goal is to convert all units to PRRS-negative status.

Sow replacement rates average 45%. Culling is not based just on lameness or poor breedback performance as is the case in many herds, states Weihs. Once sow performance starts to dip after a few parities, sows are replaced.


Weihs professes a “do it right” mentality when it comes to state-of-the art manure management technology.

In the farrow-to-wean systems run by NPP II, manure from 8-to-12-ft.-deep sow gestation manure pits and 2- ft.-deep farrowing pits are injected into the soil, normally during the spring and fall. Contract manure applicators use umbilical cord and tank injection systems, along with flow meters and pressure gauges, to monitor application rates. Neighbors are notified of application times in advance by letter.

Indiana Acquisition

At the Crawfordsville, IN, operation, the previous owner had a record number of manure spills and fish kills, which resulted in the loss of the producer's permit and the eventual sale of the operation to NPP II.

The Iowa company has worked with the state government and local environmental groups in Indiana to rectify concerns. As the operation was converted from farrow to finish to farrow to wean, existing concrete pit walls were supported by second concrete walls built inside the structures. Pipelines and clean-out ports are being replaced and surrounding soils returned to proper environmental standards.

Being a progressive producer and solid community partner has brought its rewards for Weihs, his team and NPP II investors. A number of customers are also investors, based on the company's principle that customers should always have the option to own a piece of the farrowing business.

Return on investment has averaged in the targeted range of 20-30% for NPP II's business.

Investor, Customer Opportunities

Getting investors and customers to come into the hog business in the past few years has not been an easy task, what with all of the large pork production companies that have had financial hardships, says Gary Weihs, managing partner of Natural Pork Production (NPP) II, a farrow-to-wean operation based in the rolling hills of southwest Iowa at Harlan.

That's why Weihs has surrounded himself with partners who include a savvy group of engineers, financial planners and a 20-year veteran of the Farm Credit agency to help build a sound pork business.

Partner Mark Zaccone is slowly taking over the day-to-day operation of NPP II to free Weihs to develop other agricultural businesses within Weihs Enterprises. One such endeavor is to spark development of a renewed dairy industry in Iowa.

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 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,

Amino Acids and Their Limitations

To use crystalline amino acids in low-protein diets effectively, and to minimize nitrogen excretion, you must first understand their limitations.

The use of lysine and other crystalline amino acids in low-protein diets effectively reduces the excesses of other amino acids beyond a pig's requirement and reduces nitrogen excretion. That's common knowledge. But to effectively use those crystalline amino acids, it is important to know the order in which they are limiting in various feedstuffs and the magnitude of difference between them, says University of Kentucky swine nutritionist Gary Cromwell.

Protein levels can be reduced by 4% without reducing performance if threonine, tryptophan and methionine are supplemented along with lysine, according to Cromwell. A prediction model developed in 2003 by Kentucky researchers showed a 10% reduction in nitrogen (N) excretion for every 1% decrease in dietary protein.

L-threonine and L-tryptophan have considerable potential as supplements for pigs because they generally are next to lysine in their order of limitation. Until recently, the high cost of these two amino acids prohibited their usage. Recent developments in biotechnology, new fermentation techniques and other new technological advances, however, have brought these amino acids (especially threonine) into the marketplace, Cromwell says. Currently, threonine is about the same price as lysine-HCL. Tryptophan is still expensive (about 10 times the price of lysine and threonine), but much less is needed in diets.

DL-methionine or methionine hydroxy analog (MHA) is almost universally used in poultry diets because it is the bird's first-limiting amino acid, but is generally not in the upper category of limiting amino acids for pigs. An exception would be for complex diets containing dried blood products (plasma or cells) or dried whey.

Limiting Amino Acid Order

To use crystalline amino acids in diets, it is important to know the order in which they are limiting when various feedstuffs and combinations of feedstuffs are fed, and the relative “distance” (or magnitude of difference) between the amino acids in that order, explains Cromwell.

Table 1. Essential Amino Acids in Corn-Soybean Meal Diets Containing Various Protein Levelsabc
Amino Requirement Dietary Crude Protein, %
acid 110 lb. pig 17 16 15 14 13 12 11 10 9 8
Lysine 0.84 0.88 0.81 0.74 0.67 0.60 0.53 0.46 0.39 0.32 0.25
Arginine 0.32 1.07 0.99 0.91 0.83 0.75 0.67 0.59 0.51 0.43 0.37
Histidine 0.27 0.46 0.44 0.41 0.38 0.36 0.33 0.30 0.28 0.25 0.22
Isoleucine 0.46 0.70 0.65 0.60 0.56 0.51 0.46 0.41 0.37 0.32 0.27
Leucine 0.80 1.57 1.50 1.44 1.37 1.30 1.23 1.16 1.10 1.03 0.97
Methionine + Cystine 0.48 0.59 0.56 0.54 0.51 0.48 0.46 0.43 0.40 0.38 0.35
Phenylalinine + Tyrosine 0.77 1.44 1.35 1.25 1.16 1.07 0.98 0.89 0.80 0.71 0.62
Threonine 0.55 0.64 0.60 0.56 0.52 0.48 0.44 0.40 0.36 0.32 0.28
Tryptophan 0.15 0.19 0.18 0.16 0.15 0.13 0.12 0.10 0.09 0.07 0.06
Valine 0.57 0.81 0.76 0.71 0.66 0.62 0.57 0.52 0.47 0.42 0.38
aAmino acid (total) requirements of a 50 kg (110 lb.) pig of high-medium lean growth rate (325 g./day of carcass fat-free lean) and consuming a fortified corn-soybean meal diet containing 2.5% minerals, vitamins and additives (3,400 kcal DE/kg) (NRC, 1998).
bAmino acids in shaded areas represent deficient levels.
cThe 17% protein diet consists of 74.8% corn and 22.8% dehulled soybean meal, and the 8% protein diet consists of 97.5% corn and no dehulled soybean meal. Every 1% increase in soybean meal represents an increase of 0.39% dietary protein. Similarly, every 1% change in dietary protein represents a change of 2.53% in soybean meal and a change of 0.07% in lysine.

For example, tryptophan is the first-limiting amino acid in corn and methionine is the first-limiting amino acid in soybean meal, but lysine is first limiting in a corn-soybean meal blend.

“For years, nutritionists assumed tryptophan was the second-limiting amino acid in a corn-soybean meal blend, but now we know tryptophan and threonine are almost equally limiting in their order,” says the Kentucky animal scientist.

Interestingly, threonine is more limiting than tryptophan in a corn-soybean meal diet in young pigs, while tryptophan is more limiting in older finishing pigs. And it is important to note that supplementing an amino acid that is fourth-limiting is of no benefit, and may be a detriment, if the second- and third-limiting amino acids are deficient, Cromwell adds.

Table 1 shows the amino acids that are present in a corn-soybean meal diet blended to provide from 8% to 17% crude protein. By comparing the amino acids at each protein level, one can approximate the order that the amino acids become limiting for a 50- kg (110 lb.) pig.

Cromwell offers this example: Going from left to right in the table (decreasing protein and decreasing soybean meal) it is obvious that lysine is first limiting, threonine and tryptophan are next and methionine + cystine, isoleucine and valine follow. Ample amounts of arginine and leucine and almost enough histidine and the aromatic amino acids (phenylalanine + tyrosine) are present in an all-corn diet without further protein supplementation.

Determining Amino Acid Order

Several years ago, Cromwell and his colleagues developed a visual method shown in Figures 1-3, for determining the order in which amino acids become deficient, and the magnitude of the order. It is surprisingly precise and accurate, says Cromwell, providing the amino acid levels in the feedstuffs being tested are accurate.

The first example, Figure 1, shows the six most limiting amino acids provided by a blend of ingredients, such as a corn-soybean meal diet. For such a blend, the left vertical axis gives the percent of the requirement met by corn, and the right vertical axis gives the percent of the requirement met by a soybean meal (25%) and corn (72.5%) blend. The horizontal line gives the amino acid requirements for a 50-kg (110 lb) pig. The point at which the amino acid lines intersect the requirement line indicates the order that amino acids become deficient.

In other words, the order of limitation is determined by the order that the amino acids intersect the National Research Council (NRC) requirement line, going from right to left.

In this example, lysine is first limiting, followed by threonine, tryptophan the sulfur amino acids (methionine + cystine), valine and isoleucine.

A wheat-soybean meal blend is first limiting in lysine and second in threonine (Figure 2). In a corn-meat meal blend (Figure 3), tryptophan is first limiting, lysine is second and threonine is third limiting.

Table 2 shows the six amino acids in order of the most limiting to the least limiting in commonly used cereal grains, protein supplements and other ingredients. The requirements of a 50-kg (110 lb.) pig are used, and only the six amino acids that are most likely to be limiting — lysine, threonine, tryptophan, methionine + cystine, isoleucine and valine — are given.

The order in which the amino acids become limiting changes as pigs increase in body weight and their requirements lessen.

Table 2. Limiting Amino Acids in Selected Feed Ingredients, Simple Diets and Complex Diets for Swineab
Limiting Amino Acids
First Second Third Fourth Fifth Sixth
Cereal grains
Corn Lys Trp Thr Ile Val M+C
Sorghum Lys Thr Trp M+C (Valb Ileb)
Wheat Lys Thr (Ileb Valb M+Cb) Trp
Barley Lys Thr M+C Ile (Trpb Valb)
Oats Lys Thr Trp Ile Val M+C
Protein sources
Soybean meal M+C Thr Lys Val Trp Ile
Canola meal Lys (Thrb Trpb) (Ileb Valb) M+C
Cottonseed meal Lys Thr (Ileb M+Cb) (Valb Trpb)
Meat meal Trp M+C (Ileb Thrb Lysb) Val
Meat and bone meal Trp M+C (Thrb Ileb Lysb) Val
Blood meal Ile M+C Thr Lys Trp Val
Fish meal Trp (Thrb M+Cb) Val (Ileb Lysb)
Dried plasma Ile M+C Lys (Thrb Valb) Trp
Dried blood cells Ile M+C Thr Trp Lys Val
Dried whey M+C (Lysb Val)b Trp Thr Ile
Simple diets
Corn-soybean meal Lys Thr Trp M+C (Valb Ileb)
Corn-canola Lys Trp Thr Ile Val M+C
Corn-meat meal Trp Lys Thr Ile M+C Val
Corn-meat and bone meal Trp Lys Thr Ile M+C Val
Corn-fish meal Trp Lys Thr Ile Val M+C
Corn-cottonseed meal Lys Thr Trp Ile (Valb M+Cb)
Sorghum-soybean meal Lys Thr M+C Trp Val Ile
Wheat-soybean meal Lys Thr (Ileb Valb M+Cb) Trpc
Barley-soybean meal Lys Thr M+C (Ileb Valb Trpb)
Oats-soybean meal Lys Thr Trp Ilec Valc M+Cc
Corn-soybean meal + 5% fish meal Lys Trp Thr M+C (Ileb Valb)
Corn-soybean meal + 5% meat meal Lys Trp Thr M+C Ile Val
Complex diets
Corn-soy +30% dried wheyd M+C Lys Thr (Trpb Valb) Ile
Corn-soy + 25% whey + 6% plasmad M+C Thr (Trpb Val)b Lys Ile
Corn-soy + 10% whey + 3% cellse M+C Thr Trp Lys Val Ile
Effects of body weight (corn-soy diet)
22 lb. Lys M+C Thr Trp Val Ile
44 lb. Lys Thr M+C Trp Val Ile
110 lb. Lys Thr Trp M+C (Valb Ileb)
120 lb. Lys Trp Thr Ile Valc M+Cc
aBased on requirements for total amino acids (110 lb. barrows and gilts, 325 g. lean gain/day, 3,400 kcal DE/kg) and feedstuff composition listed by NRC (1998). Order is not included for the other four essential amino acids.
bAmino acids within parentheses are nearly equally limiting.
cNot limiting.
dRequirements of 22 lb. pigs.
eRequirements of 44 lb. pigs.
Amino acid abbreviations: Lys = lysine; Thr = threonine; Trp = tryptophan; M+C = methionine + cystine; Ile = isoleucine; Val = valine.

For example, the sulfur amino acids are second limiting in a corn-soybean meal diet for a 10-kg (22 lb.) pig, are third or fourth limiting in an intermediate-weight pig, and sixth limiting in a corn-soybean meal diet for a 120-kg (264 lb.) pig. The order of threonine and tryptophan also change as pigs increase in body weight, as do the order of isoleucine and valine.

This same procedure has been further refined by adapting the data to a digestible amino acid basis. Using digestible amino acids with this procedure is useful in determining which amino acids can be supplemented and at what levels they can be added to feed ingredients with certain poorly-digestible amino acids (such as threonine in meat meal or meat and bone meal).

Table 3. Use of Amino Acids in Reduced Protein, Corn-Soybean Meal Diets
Body weight, lb.
44 110 176 264 Avgb
Soybean meal reduction, %a 13.4 11.5 10.4 9.1 10.6
Amino acids needed
Lysine, %b 0.37 0.32 0.29 0.25 0.30
As lysine·HCl 0.47 0.41 0.37 0.32 0.38
Threonine, % 0.15 0.12 0.09 0.07 0.10
Tryptophan, % 0.039 0.036 0.035 0.033 0.035
Methionine, % 0.09 0.03 0.02
aAmount of soybean meal in a corn-soybean meal diet that can be eliminated (replaced with corn) while still meeting the requirement for the fifth-limiting amino acid (isoleucine or valine). Based on the slope procedure shown in the figures.
bWeighted average, giving twice as much weight to the 176- and 264-lb. categories.

Supplementation Economics

The general assumption is that protein can be reduced 2% in a corn-soybean meal diet if 0.15% lysine is added (0.192% lysine-HCL) for grow-finish pigs. Another way of expressing this is that 96.15 lb. of corn and 3.85 lb. of lysine-HCL is equivalent to 100 lb. of dehulled soybean meal in a ton of diet. Based on summer '04 prices of corn ($2.40/bu; $.043/lb.), soybean meal ($310/ton; $0.155/lb.), and lysine-HCL ($1.20/lb.), this amounted to a savings of about $6.75/ton of feed. At current prices of corn ($1.80/bu.), soybean meal ($175/ton), and lysine ($1.00/lb.), the savings is about $1.80/ton when lysine is used in the lower, protein diet.

What are the economics of further reducing dietary protein and using more amino acids? Averaged over several weight groups, the amount of soybean meal can be reduced by approximately 10.6% (equal to a 4% reduction in dietary protein) if the four amino acids are added at levels of approximately 0.38% lysine-HCl, 0.10% threonine, 0.035% tryptophan, and 0.02% methionine, as shown in Table 3.

Expressed another way, 199.3 lb. of corn, 7.6 lb. of lysine-HCl, 2.0 lb. of threonine, 0.7 lb. of tryptophan, and 0.4 lb. of methionine can replace 210 lb. of soybean meal in a ton of feed. Last summer, this type of diet was cost effective, resulting in a savings of $2.47/ton of feed. However, at current prices of corn, soybean meal and amino acids, this type of diet would not be economical to feed (an additional $7.95/ton), mainly due to the high cost of tryptophan.

It is important to know the limiting amino acids in cereal grains, protein supplements, by-product feeds and combinations of feed ingredients, and to understand the order that amino acids become limiting as dietary protein is reduced, concludes Cromwell. That knowledge is essential in order to utilize supplemental amino acids effectively in low-protein diets that minimize nitrogen excretion.

Pig Density, Feeding Options Studied

In-house research is used to shape feeding strategies at a top pork production company.

A few of those strategies were presented at the Midwest Swine Nutrition Conference in Indianapolis recently by Bradley Wolter, director of production technology for The Maschhoffs Inc., a 51,000-sow system that produces a million hogs a year.

Wolter oversees a $2 million wean-to-finish (W-F) research farm near Carlyle, IL, that mirrors other Maschhoff units. Nearly 100% of finishing flows through W-F systems.

The basic W-F design is a 2,400-head, double-wide building with two attached 1,200-head units under one roof, but with separate ventilation, pits and load-out chutes. The latest and largest W-F barn is a 100 × 300 ft. structure that holds 7,600 head.

One strategy Wolter has studied involves overstocking the W-F barns to increase output. In unpublished data, weaned pigs were stocked 32 head/pen (6.88 sq. ft./pig) and 64 head/pen (3.44 sq. ft./pig). Feeder trough space was 2.3 in./pig for the small group and 1.14 in./pig for the double-stocked group.

Results showed overstocking for an initial eight- to 10-week period dropped average daily gain over 7%. They chose to overstock at the 64-pigs/pen rate.

Another important consideration is the amount of feeders and water drinkers to support performance. European researchers have shown an increase in feeder-related aggression and a reduction in growth rate when pigs are provided limited feeder space, says Wolter. They determined that doubling the number of pigs/pen for eight weeks, postweaning, required additional feeder trough space to maintain performance. In that study, pigs were provided 0.8 in. vs. 1.6 in. of feeder trough space/animal.

Results showed performance was similar for the first six weeks, and then growth rate dropped 5% in pigs allocated to the reduced space between six and eight weeks, postweaning.

Another study used a tube-type combination wet/dry feeder. Results suggest providing over-stocked pigs supplemental trough space (1.5 in./pig vs. 3 in./pig or four vs. two tube spaces) tends to increase growth rate during the four-week period, postweaning.

Feed form and placement were also scrutinized at the research farm. A recent study found supplemental feeding strategies, either floor feeding or use of an automated gruel feeder, reduced the antibiotic treatments given to pigs by 50% compared to using an ad-lib feeder during the initial postweaning period.

In general, a floor-feeding protocol for weanling piglets should involve a solid floor area large enough to allow all pigs within a pen access to feed, says Wolter. While the impact of floor feeding the diet in either a gruel or dry form on pig growth appears inconsistent, in practice, routine observations of piglets floor-fed multiple times per day means producers will assess their barn more frequently, he adds. It allows them to correct alterations in ventilation, clogged feeders and assure water availability during the early growth period. They feed four times per day on floor mats, postweaning.

Their results also demonstrate that morbidity rate can increase with decreases in diet complexity during the early growth period. The choice of ingredients in piglet diets is important to maximize early growth potential, and reduce the threat of health challenges or digestive disorders after weaning, notes Wolter. He advocates feeding complex diets immediately postweaning to initiate high levels of feed intake, and then quickly switching to simpler diets.

Complex diets could contain milk products, raw and cooked cereal and animal-protein based ingredients with minimal soybean meal.

Wolter has found that pigs with decreased early growth rate have compensated in the grow-finish stage when provided adequate nutrition and special resources such as feeder trough and floor space.

Feeding strategies in W-F buildings can have a significant impact on rate of growth and morbidity, he says. And certain nutritional and environmental approaches can manipulate the animal's growth curve and help reduce production costs.

Poster Series Introduced

Sow herd mortality and culling rates have reached unacceptable levels in some herds. The attached poster is the first in a series developed to help pork producers more effectively screen replacement gilt candidates before placing them in their breeding herds.

The first poster in this series focuses on conformation and structural soundness. Whether purchasing replacement gilts or producing your own in an internal multiplication program, the poster shows examples of good and poor conformation and skeletal structure.

Structural evaluation is a process of visual appraisal by scoring or evaluating animals for proper skeletal structure and feet and leg soundness. Research has shown that certain structural conditions can affect a sow's lifetime performance in the breeding herd.

Visual appraisal can help identify replacement gilts with “buck-kneed” front legs, straight rear pasterns and swaying hips — all of which have been shown to negatively impact sow longevity.

Identifying replacement gilts with one or more of these conditions and culling them, rather than utilizing them in the breeding program, may be one of the keys to lowering breeding herd replacement rates and/or mortality rates.

In addition to the negative relationships between some leg abnormalities and longevity, research has also shown that some conformation traits have a positive effect on longevity. Specifically, soft pasterns on the front legs can be a favorable indicator of a sow's ability to remain in the breeding herd longer.

The pictures and diagrams will assist producers in identifying these conditions. Subsequent posters in February and March will focus on feet and leg soundness and reproductive trait (underlines, external genitalia) soundness, respectively.

More detailed information on the evaluation of swine for structural soundness, including a scoring system, is available from the National Swine Improvement Federation at

Heritability of Structural Soundness

Structural soundness has been shown to be moderately heritable, which means seedstock suppliers should be able to improve this trait through selection. Therefore, keep in mind that the traits contributing to structural soundness in a parent will also have an impact on their offspring.

For example, if animals with structural deficiencies (i.e., buck-kneed forelegs, straight or upright pasterns, etc.) are retained for breeding purposes, we would expect a significant number of their offspring to have this condition. Unsound animals do not perform as well as their more sound counterparts.

Additionally, unsound animals are more likely to pose problems during transportation and lairage at harvest facilities. This underscores the importance of structural soundness and its role in profitable pork production.

Environmental Factors

Many environmental factors also influence structural soundness. For example, nutrition, gender, health and level of production are factors. Housing conditions, such as degree of floor roughness, location of equipment and level of repair, pig density in all phases of production, and exercise can also influence structural soundness.

Many selection programs have largely ignored structural soundness in recent years, while more emphasis has been placed on other economically important production traits. Ignoring structural soundness has resulted in an increasing number of animals exhibiting one or more structural problems.

While producers may think that these conditions only rarely occur, the reality is that most operations can find one or more of these conditions within any group of replacement females.

The organizers of this project visited only three operations to find the vast array of structural imperfections used in this poster series. This reinforces how common many of these conditions are, and that no operation is free of all of these challenges.

When to Cull

It should be noted that not all animals have perfect structural and reproductive soundness. Any selection program must evaluate and prioritize the importance of numerous traits. Compromises are often made with the level of structural soundness, degree of muscling or fatness and other traits under consideration.

For example, should a gilt be culled because of a minor structural defect at the expense of leaving a farrowing crate empty? Probably not, but the important point is to recognize the consequences of retaining these animals.

Ask yourself: How will a defect affect an individual's productivity in the farrowing crate? How will it impact the productivity of her offspring?

This series of posters was produced through the cooperative efforts of Pork Checkoff, National Swine Registry, National Hog Farmer and Iowa State University Swine Extension.

Additional copies of the posters are available free to U.S. producers and agricultural educators. Non-producer and foreign poster orders are available at 50¢ each. Contact Pork Checkoff at (800) 456-PORK or visit the Pork Checkoff catalogue at The complete set of three posters will be available after March 15.