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Articles from 2004 In January

General Editorial Mail

Environmental Stewards Nominations Now Open

Pork producers have a long-standing record of conscientious environmental stewardship. In an effort to publicly recognize this commitment to managing their pork production systems in harmony with our environmental resources, National Hog Farmer and the National Pork Board have joined forces in developing a program to recognize those who have built exemplary environmental management programs.

This year marks the 10th anniversary of the Environmental Stewards of the Pork Industry recognition program. In those years, this program has allowed us to showcase pork producers who are doing an outstanding job of adopting state-of-the-art environmental and nutrient management practices. In doing so, the pork industry has gained a greater public awareness and appreciation for pork producers' environmental ethics. Additionally, this program has allowed us to reinforce to the nation's policymakers and the general news media the conscientious role pork producers play in guarding our valuable natural resources.

Areas of Evaluation

Nominations are now open for the class of 2004 Environmental Stewards. A national selection committee comprised of pork producers and experts from various disciplines, including agricultural engineering, natural resources, environmental management and others, will review all nominations. The operations will be evaluated in eight areas: general production and background; manure nutrient management; soil conservation practices; odor control technologies and management strategies; farm aesthetics and neighbor relations; wildlife habitat; adoption of innovative ideas; and a short essay describing their view of environmental stewardship.

Nominations Open to All

This recognition program is open to production systems of all types and sizes. Since 1995, winners have represented family owned and operated farms, management teams working within an integrated system and contract producers.

Individual producers, Extension agents, veterinarians or others may submit nominations. A nomination should be focused on a single production site, outlining the owner's and/or manager's diligence and expertise in applying their environmental management program. Each of four regional winners will receive a special plaque, an expense-paid trip to the awards ceremony and a $1,000 cash honorarium. In addition, each steward's farm will be featured in a special report published in the September issue of National Hog Farmer.

Additional information and an easy-to-use nomination form is available on the sponsors' Web sites: or Click on the Environmental Stewards banner. Or, request nomination forms by calling Cindy Cunningham, National Pork Board, (800) 456-7675, or Dale Miller, National Hog Farmer, (800) 722-5334. Send nominations to: National Pork Board, Attention: Environmental Stewards, P.O. Box 9114, Des Moines, IA 50306-9620. Nominations must be postmarked by March 31, 2004.

All Finishing Diarrhea Is Not Ileitis

Diarrhea is present in many finishing barns. Many producers would point a finger at ileitis as the cause of finishing diarrhea. Vaccine and treatment failure for ileitis are often incriminated when diarrhea is observed in the finishing phase of production.

In fact, there are a number of other causes of finishing diarrhea.

Case Study No. 1

We were called to look at a case of recurrent diarrhea in newly arrived feeder pigs. This pork producer receives groups of 750 feeder pigs weighing 50-55 lb., which are placed in fully slotted, double-curtain-sided finishers. At 5-7 days post-arrival, up to 50% would have diarrhea. Many became poor-doers; up to 5% would die.

A laboratory diagnostic workup yielded a hemolytic E. coli., a disease commonly seen in nurseries that is becoming a more common cause of finishing diarrhea.

Since these 50-lb. pigs broke so frequently with diarrhea, we were concerned that the pigs did not make the transition between diets well. We tried to nutritionally match the last nursery diet and the finisher receiving diet. The last nursery diet was formulated with soybean meal, corn, canola meal and barley. The finishing receiving diet was an aggressive feeding program with corn-soybean meal rations that contained 4-5% added choice white grease.

We changed the receiving diet, adding more fiber and less choice white grease. These changes have greatly reduced the incidence and death loss due to hemolytic E. coli in finishing pigs.

We are currently making the last nursery diet more like the receiving diet to attain an even smoother transition for finishing pigs.

Case Study No. 2

Last fall, we were called to look at a group of 60-lb. finishing pigs. These single-source pigs came in as weanlings, all barrows from a maternal line gilt replacement program. This unit received 350 pigs every 8-9 weeks. Pigs spent 8-9 weeks in the nursery before being moved to an on-site finisher.

The finisher is a fully slotted, double-curtain-sided facility with two ages of pigs in two separate rooms. This unit has a history of both ileitis and hemolytic E. coli.

About two weeks after pig placement in the finisher, the owner noticed diarrhea in some pens. The incidence of diarrhea was severe and affected up to 60-80% of the pigs, yet no pigs died during this bout of diarrhea. It was assumed that these pigs had ileitis and treatment was initiated.

Following the incident, we were called out to perform a diagnostic workup. Tissue analysis pointed to Transmissible gastroenteritis (TGE). Death loss was quite low in finished pigs. The low mortality and high percentage of finishing pigs affected were tipoffs that this problem was not due to ileitis.

Since TGE is a virus that removes the villi in the gut where absorption of nutrients and fluids occur, the diarrhea will not stop until the villi grow back. This usually takes 3-5 days. We successfully treated pigs with electrolytes in the water, which is the best approach until pigs can get better on their own.

Case Study No. 3

We were called to look at a case of suspected ileitis in a 600-head finishing facility that had a known history of acute ileitis. The pig flow came from a large production system that sends 600 weaned pigs every eight weeks. These pigs stay in a nursery for eight weeks, then move to an on-site or off-site finisher.

This unit had a history of acute ileitis in finishing. Ileitis vaccine had been used with relatively good success.

So when diarrhea returned, it was assumed the ileitis vaccination program failed. Diarrhea affected 3-5% of the pigs and disease progression often ended in death. A very low percentage of pigs showed signs of cyanosis (discolored ears and extremities) and had a fever of 105° F.

On postmortem examination, enlarged livers, spleens and lymph nodes were noted. Salmonella cholerasuis was isolated.

Antibiotic treatment must start early to be effective. In general, this bacteria will be resistant to the penicillins and tetracyclines and sensitive to the ampicillins and ceftiofur.


Diarrhea in the finisher is not necessarily due to ileitis vaccine or treatment failure. These three examples of diarrhea were thought to be cases of ileitis.

We also see nutritional causes, whipworms, Brachyspira pilosicoli and a variety of other enteric problems in pigs that we service.

Making sure to involve your swine veterinarian to get an accurate diagnosis and treatment plan becomes an important decision when wading through the sometimes confusing clinical signs of finishing pig diarrhea.

A Minute Per Pig Pays Big Dividends

Bi-weekly trips across the scale land 90% of pigs in the packer's core target weight range.

Taking time to weigh pigs individually is paying big dividends for the Prairie Swine Centre's Research Barn in Elstow, Saskatchewan. Starting at 20 weeks into the finishing period, pigs are weighed every two weeks to increase the odds that they will be marketed in the core target weight range, 240-275 lb. live weight (187-220 lb. dress weight).

An investment of less than a minute of one employee's time per pig, every two weeks, has increased the percentage of hogs that hit the core weight from 60% to over 90%.

After the core weight premiums and improved index scores have been tallied, the barn pockets an extra $5-10 (Canadian $)/pig ($1 Canadian = $0.753 US$). Since the Centre markets 13,000 to 14,000 pigs/year to Maple Leaf Foods in Saskatoon (formerly Schneiders), that adds up to an extra $65,000 to $140,000 annually. That's not a bad payback for a few days' work.

Until February 2003, the Swine Centre, like many hog operations, relied on eyeballing to estimate market weights. Results were less than satisfactory; only 60% fell within the core weight range of the marketing grid in 2002.

“We felt we should be able to do a lot better than 60% in core,” said barn manager Troy Donauer. “We thought that weighing pigs would be a good place to start, and it doesn't take a lot of time to get results.”

How the System Works

The Swine Centre targets two weight ranges during weighing. Animals ready for market the following week, 242 lb. and up, are marked with blue. Pigs ready to be marketed in two weeks, weighing about 231 lb., receive a red mark. The heavier, blue-marked pigs are penned separately for early shipping, while the rest return to their pens for another two weeks before being weighed again.

“We may only get 20 or 30 pigs out of the room on the first week,” Donauer says, “but those are 20 or 30 that aren't going to be shipped out heavy two weeks later. Getting the heavy ones out early benefits the remaining animals. You reduce overcrowding by getting the big guys out of the pen, which improves access to feeder space. The sooner you get the heavy ones out, the more benefits you get throughout your program.”

Roughly 25% of the animals are ready to be shipped after the first weighing, Donauer explains; 65% are ready to go after the second weighing. The remaining 10%, the tail-enders, are weighed three times.

Donauer is thrilled with the results and a bit puzzled why they never implemented such a simple, cost-effective practice years ago. “It's just a matter of weighing pigs; it's not rocket science,” he adds. “Just weigh them, and if they're heavy you market them; if they're not, you don't. It's simple to do, so we just decided to invest the extra time and effort and it has paid off. I wish the results with everything we did were this cut and dried.”

Now that the Swine Centre staff has reached 90% within core, they are now striving for 94%. “There are some dynamics if we can get half of our pigs on the heavy side of core,” Donauer says. “You can make a little extra money by having lean pigs, but having them just that little bit heavier.”

Homemade Weighing System

The Swine Centre utilizes a homemade 4 × 8-ft., in-floor scale, which was built into the main hallway of the barn when it was originally constructed. The system's chutes and gates are simple enough to weigh the pigs with just a one-man operation. The hallways on either side of the scale are used as holding pens during the procedure. A room of 270 pigs can be easily weighed in four hours.

“The gates are 3-4 ft. wide, so there is lots of room to get one animal in,” Donauer says. “The best thing about it, and I think the only way to make it work, is having a system of ropes to open and close the exit gate from the entrance side. Gates are on a hinge with a spring, so if you pull on the rope to unlatch the gate, it swings open. A second rope is used to close the gate and re-latch it. The design makes it possible for one person to put an animal in, weigh it, mark it, pull the rope and let them out, close it and move on to the next one without having to go back and forth. It saves a lot of extra time.

“Our labor costs haven't changed, since we haven't had to hire anybody extra,” says Donauer. “That extra income is basically added to the bottom line. Even if you had to hire an extra person for one day a week, it's worthwhile. At ten bucks a pig, you don't have to sell very many pigs to cover any extra wages.”

Herd Health Upgrades Require Homework

One of the biggest, most difficult stumbling blocks on the road to stable, profitable pork production is often herd health.

Addressing the “Genetics of Pig Health” Symposium held in Des Moines, Luc Dufresne, DVM with PIC Inc., says there is no room for generalizations when analyzing the merits and payback potential of most health improvement programs.

“In our mature industry, few producers are currently starting from scratch, so most health improvement programs incur direct and indirect costs that need to be recovered by increased efficiency (such as) lower cost of production and increased throughput and/or increased product value (through) higher premiums,” he states.

Of course, herd health status does not fully explain the huge variation in production performance seen across the industry, he says. “As same health-status systems also vary in their performance, it would be naïve to believe that health improvement will have the same impact in all production schemes,” he adds.

Before tackling a health improvement project, Dufresne says to document data from your farm, then support it with literature and data from similar production systems.

Table 1. Influence of Different Production Trait Improvements on Margin and Throughput
Trait change Margin/cwt. lb./sow/year (throughput)
.05 lb. Avg. daily gain (3.0%) $0.80 150
.25 No. born alive/litter $0.28 108
.05 Increase in feed efficiency $0.27 0
1% Mortality wean-to-finish $0.25 42.7
2% Increase in coefficient of variation $0.42 5
.05 Litters/sow/year (2.0%) $0.21 96
2.0% PWM (preweaning mortality) $0.20 73.8
5% Farrowing rate $0.12 20
2% Sow mortality (50% pregnant) $0.12 20

Is It Worth It?

The first step in analyzing the merit of (re)populating a system with high-health animals, or initiating disease elimination strategies, is thoroughly understanding the system and effectively estimating the cost of disease within that system.

“Do not forget, profitability is a dynamic equation with independent production parameters that can work for you — or against you,” he adds.

To determine profitability, the economic value of each production parameter must be evaluated against how it affects throughput and margin. He offers this simple formula:

Throughput × Margin = Profitability.

Dufresne calls this “redneck economics” and explains that “throughput” is a measure of the number of product made per unit of production and unit of time (i.e. pigs marketed/sow/year or pounds sold/1,000 sows/week). “Margin” is simply the revenue made when the product is sold minus cost of production.

“An enterprise can increase profitability by either increasing throughput or by increasing margin,” he continues. Margin can be improved by reducing costs or increasing revenue per unit.

Each component of the equation is not independent — they can work synergistically or antagonistically. “For this reason, it is necessary to look at the impact a health improvement (or any other change in production) can have on the throughput and the margin components of the formula,” he says.

Health improvement strategies can improve profitability by increasing throughput (i.e. pigs sold/sow/year) and margin (i.e. lower cost/lb. marketed; increased premium/hog marketed).

Evaluating the economic impact of health improvement is especially challenging because the estimate is based on the change in performance parameters and their impact on profitability. “A sound evaluation must combine historic data from the production system involved, combined with data from literature and/or data from other very similar systems,” he explains.

Even then, it is important to consider the risk of a partial or total failure of the health improvement project. And, if the project is successful, one must consider the risk of recontamination by the same or a new disease agent, he reminds.

Next Step

Once performance improvements have been estimated, the next step is to evaluate how it will affect profitability. Dufresne reviewed the impact of key performance parameters on either throughput or margin, as follows:

Average Daily Gain (ADG): The economic impact varies depending upon space availability. If growing pig space is limited and time dictates marketing, ADG improvement will be the most important factor to improve profitability. Selling at heavier weights increases throughput and also increases margin by reducing costs — spreading feeder pig and facility costs over more pounds sold. “But don't forget, selling heavier hogs could affect carcass premiums or discounts,” he adds.

Feed Efficiency (FE): Improved FE increases margins by reducing feed cost per pound produced.

Number Born Alive (NBA), Pre- and Postweaning Mortality: An increase in NBA or a reduction in pre-weaning mortalities will have a significant impact on costs and throughput. Reducing postweaning mortalities has a bigger impact on costs simply because the animal is worth more. However, while looking at mortality, be sure to consider whether the surviving animals are good, marketable hogs or culls. Look for the percentage of animals sold to the primary market — rather than mortality and livability — on closeout reports, he suggests.

Sow Mortality: This is both an important animal welfare issue and an employee morale issue. The major economic impact of sow mortality is loss of cull value and the value of the litter, if she is pregnant.

Litters/Sow/Year (L/S/Y) and Farrowing Rate (FR): L/S/Y is a measure of sow herd efficiency, including non-productive days. Farrowing rate, a component of L/S/Y, reacts in the same way.

If the sow inventory is fixed, increasing L/S/Y increases weekly throughput, profitability rises and the “per unit” costs decline. However, if L/S/Y increases but sow inventory is adjusted to maintain a constant throughput, the impact on profitability will be much smaller, Dufresne points out. “Be careful when trying to maximize L/S/Y, especially if it is done at the expense of lactation length or gilt acclimation. The gain in L/S/Y can be more than lost in litter size and poor piglet performance,” he adds.

Dufresne uses Table 1 (p. 34) to illustrate the impact production improvement can have on profitability. He looks at cost and throughput using average production and cost parameters from several large production systems. His assumptions for Table 1 include a system with limited finisher space (fixed market age), with breeding targets and inventory adjusted to farrowing rate. Current cost of production is set at $38/cwt. and market price is $40/cwt., live weight.

In this case, ADG has the largest impact on both cost reduction and throughput. Improvement in sow mortality and farrowing rate has a limited impact on cost and throughput.

Fixed Costs/Week/Pig Space (Utilities, Maintenance, Taxes, Depreciation and Interest Costs*)
Interest Rate
$/pig space 6% 8% 10% 12% 14% 16%
$75.00 $0.28 $0.30 $0.34 $0.37 $0.41 $0.45
$100.00 $0.36 $0.39 $0.43 $0.47 $0.51 $0.55
$125.00 $0.44 $0.47 $0.52 $0.57 $0.62 $0.66
$150.00 $0.50 $0.55 $0.61 $0.67 $0.73 $0.78
$175.00 $0.58 $0.63 $0.70 $0.77 $0.83 $0.90
$200.00 $0.64 $0.71 $0.79 $0.87 $0.94 $1.02
$225.00 $0.72 $0.79 $0.88 $0.97 $1.05 $1.14
$250.00 $0.78 $0.87 $0.97 $1.07 $1.16 $1.26
$250.00 $0.78 $0.87 $0.97 $1.07 $1.16 $1.26
$275.00 $0.86 $0.95 $1.06 $1.17 $1.27 $1.38
$300.00 $0.92 $1.03 $1.15 $1.26 $1.38 $1.49
*Utilities cost $0.05/pig/week, maintenance = 2% of building cost/year, taxes = $1,000 depreciation over 15 years. Financing of 100% of value of the facilities.

Do Your Homework

Before undertaking a health improvement program, Luc Dufresne, DVM with PIC, Inc. suggests a thorough evaluation of your system.

“Putting a value on health improvement is not an easy task. You must resist generalizations to avoid creating false expectations.” His checklist includes:

  • Final product: Weaned pigs, market hogs, replacement animals, etc.

  • Performance data: Identify traits that need attention.

  • System capacity: Sell by fixed weight or fixed time; where are the bottlenecks?

  • Cost of production: Consider fixed and variable costs to identify areas of cost savings.

  • Health status/history: Document all diseases and outbreaks and their impact on cost of production.

  • Pathogens: It is critical to understand the host, environmental characteristics, pathogenesis of the agent, duration of shedding, latency and viability of the agent. Answer this question: “Do we know enough about the disease agent to eliminate it and keep it out?”

  • Facility design: Plan pig flow during the health upgrade. Facility design will influence downtime and the need for extra facilities during the project.

  • Impact on genetic potential: If a new genetic supplier is necessary to reach a new health status, it is also important to evaluate the impact the change will have on overall production performance.

  • Biosecurity assessment: Assuming an improved health status can be attained, it is important to assess the risk of reintroducing any pathogens over time. Consider all traffic patterns, hog density, prevailing winds/aerial spread, etc.

  • Facility costs and interest rates: “Cost of facilities and interest rates on loans to finance buildings and equipment will impact the cost of a project where depopulation and/or downtime of facilities are required,” Dufresne notes. The table below illustrates the cost/week of leaving growing pig facilities sit empty, using various facility costs and interest rates.

    In addition, Dufresne suggests calculating the costs associated with the health improvement program:

  • Medication costs: Vaccines, antibiotics, disinfectants, insecticides, etc.

  • Diagnostic tests: Serology, bacteriology, virology, necropsy; ask your veterinarian for estimates.

  • Inventory adjustments: Costs associated with changes in inventory, loss of throughput and revenue.

  • Facility rental: Costs of off-site breeding, partial depopulation, segregated early weaning, etc.

  • Personnel: Extra full-time or part-time help.

  • Downtime: Calculate all added costs and revenue loss associated with the project.

product news

PowerMaster Pig Injector

Durvet introduces the new 2 ml. PowerMaster Pig Injector. Powered by LP gas, the unit has the capacity to fire a perfectly calibrated dose of selected, injectable pharmaceutical or biological product. Recycling in as little as one-half second between injections, the speed, combined with the injector's accuracy, ease of use and safety, helps pork producers vaccinate large numbers of animals in a fraction of the time it would take using a traditional inoculation delivery device. The injector can be calibrated to administer 0.5 ml. increments up to a full 2 ml. dose. Constructed of strong, lightweight plastic and metal, the unit is built to last with minimal maintenance required.
(Circle Reply Card No. 101)

Gene Marker for Daily Gain

Newsham Genetics, LC, has announced that its Belgian sister company, Gentec NV, and researchers at the University of Liege, also in Belgium, have discovered a new gene marker for daily gain in swine. Brent Mitchell, chief operating officer for Newsham Genetics says, “We expect this development to help us fine-tune our unique selection process and set a new performance standard.”

Nadine Buys, the molecular geneticist at Gentec involved with the discovery, says the patent-pending marker is linked to the more than 25g. (0.055 lb.) per day of variation in daily gain on slaughter pigs, calculated from birth to slaughter. “The new marker has no negative influence on backfat thickness, lean meat percentage or meat quality characteristics,” she adds. “This means that the new marker is a real breakthrough, as it will not only improve turnover in finishing units, but also will have a significant influence on feed conversion.”
(Circle Reply Card No. 102)

Protect Your Hands

Many livestock medications, chemicals, detergents and solvents are absorbed directly into workers' skin, causing skin disorders or dry, cracked skin. Gloves In A Bottle, a lotion, makes the outer layer of skin work like an invisible pair of gloves to keep the moisture-robbing irritants out while retaining natural moisture. It is virtually undetectable when dry, lasts four hours or more and comes off naturally.
(Circle Reply Card No. 103)

Utility Tractor

New Holland's new TC49DA and TC55DA Boomer utility tractors have the power for tough jobs. Because of their convenient size and ample power, these tractors are productive on the job, yet are easy to transport on a trailer. The sleeveless parent bore engine design of the tractor features a deep skirt and ribbed block for added strength and durability. The unique Omega-shaped bowl at the top of each piston helps to thoroughly mix air and fuel, producing more horsepower per gallon of fuel and turning more of its gross engine horsepower into usable power at the PTO and drawbar. The 18LA Quick-Latch front-end loader, specifically designed for the Boomer models, features a unique, curved-boom design with a 2,500-lb. lift capacity.
(Circle Reply Card No. 104)

Swine Influenza Virus Vaccine

Schering-Plough Animal Health Corp. introduces the first trivalent vaccine for swine influenza virus (SIV). MaxiVac Excell 3, a killed-virus vaccine, protects against all major strains of SIV circulating in the U.S. swine population. It features a new variant or “reassortant” strain of H1N1 subtype in addition to the classical H1N1 subtype that has been circulating in U.S. hogs for decades. The vaccine also contains an H3N2 subtype that protects against the Cluster 1 Texas-like H3N2 subtype, as well as cross-protects against Cluster III variants of H3N2. MaxiVac Excell 3 is approved for use in pigs 5 weeks of age or older, including boars and pregnant sows. The vaccine also has been shown to reduce pneumonia and lung infection following challenge. The company recommends vaccinating healthy pigs with a 2 ml. intramuscular dose and revaccinating two to three weeks later.
(Circle Reply Card No. 105)

Reduce Pit Crust

Accelerator Plus from Agtech Products, Inc. is the first product developed specifically to reduce pit crust on stored manure primarily caused by the accumulation of the pericarp (outer shell of corn). The product contains enzymes chosen for their ability to digest the pericarp of the corn kernel and other hard-to-digest feed substances, thereby limiting the formation of the crust. Pit crust also provides a more ideal environment for flies and rodents; therefore, the product also serves as an important part of any biosecurity program.
(Circle Reply Card No. 106)

Audit Outlines 10-Year Pork Quality Shifts

The composition of the average market hog has changed significantly in the last decade — tipping the scales at heavier weights and with considerably less backfat.

That is the summary of the American Meat Science Association's “Benchmarking Value in the Pork Supply Chain” final report released recently.

The benchmarking project, supported by pork checkoff, several packers and genetic companies, surveyed pork processing companies to identify, quantify and rank factors influencing pork quality, explains Floyd McKeith, lead researcher from the University of Illinois. The survey and resultant report drew on the original Pork Chain Quality Audit Survey from 1993, which identified and quantified several pork quality issues, he notes.

In that early work, producers, packers and processors zeroed in on key issues causing economic losses. They included: excessive fat, inadequate muscle color/water-holding capacity, inconsistent live weights, excessive abscesses and bruising. The 2003 survey provided a follow-up to those pork quality issues.

Meat processors provided slaughter data on 64% of the 98 million federally inspected barrows and gilts slaughtered in 2002. The survey featured three phases. The first surveyed packers; the second studied products manufactured from various fresh pork cuts; and the third looked at the consumer acceptability of different products at varied pricing levels. All major hog-producing areas in the U.S. were represented.

From the quality perspective, the survey reveals two definitions of pork quality currently in use. “One pertains to the technical aspects of pork quality and is defined by purge loss, water-holding capacity, objective color, percent fat and percent lean,” McKeith explains. The other reflects the consumer's expectation of quality, which focuses on subjective color, tenderness, juiciness, flavor and nutrition, he adds.

Notable Carcass Trait Changes

Compositionally, the 1993 concern about excessive fat was addressed handily. Backfat was reduced 36% during the decade that followed, trimming average backfat thickness from 1.07 in. to 0.69 in.

Looking closer at the distribution of backfat depths, Table 1 verifies that nearly 96% of the hogs represented in the survey had less than 0.98 in. of backfat. “This significant improvement can be credited with improved genetics, feeding techniques, marketing plans, housing and an understanding of environmental influences and their impacts,” McKeith says.

The carcass trait, backfat and live weight data in Table 2 reinforces that, as backfat decreases, overall weight and muscle increases. This change in composition is also reflected in Table 3. The average U.S. market hog now has 55.5% lean muscle, up from the 49.5% recorded in the '93 audit. In 2003, nearly two-thirds of market hogs landed in the 54-56.9% muscle slot. Of course, that leaves over a third of U.S. market hog carcasses with less than 53.9% muscle.

Even as backfat was being trimmed, live weights increased by 10 lb. during the decade — from a 245-lb. average to just over 255 lb. Nearly 45% of the market hogs fell within the middleweight category (242-269 lb.). The next largest category, 271-300 lb., accounted for just over 34% of market hogs; 14.1% landed in the 200-240-lb. range. At the extremes, 5.9% weighed over 300 lb., 1.1% less than 200 lb.

“This trend reflects the increase in slaughter weights currently in practice today,” McKeith observes. “Increases in average daily gain, feed efficiency and improved nutrition can also be attributed to the processing weight increase.”

Table 1. National Pork Benchmarking Audit Estimate of Backfat Thickness of U.S. Market Hogs
Backfat thickness range, in. Carcasses with backfat thickness in this range, % Minimum Maximum
Below .59 12.3 0.0 15.0
.59 - .78 55.3 2.0 53.0
.78 - .98 28.1 5.0 29.0
.98 - 1.18 3.5 2.0 42.0
1.18 - 1.38 0.7 0.0 42.0
1.38 - 1.58 0.1 0.0 25.0
1.58 - 1.78 0.0 0.0 25.0
Over 1.78 0.0 0.0 6.0

Table 2. National Pork Benchmarking Audit Estimate of Carcass Traits of U.S. Market Hogs1
Trait 1993 2003
Live weight, lb. 245.1 255.7
Backfat thickness, in. 1.07 0.69
Carcass muscle, % 49.5 55.5
Ham weight, lb. 21.8 26.0
Loin weight, lb. 17.2 20.9
Boston butt weight, lb. 6.2 6.0
Belly weight, lb. 14.8 15.0
1Estimates of variability are the ranges of the specific traits and the frequency of hogs falling into those ranges which are included in the tables.

Logically, the heavier live weights yielded heavier carcasses, which, of course, translated to heavier wholesale cuts. A comparison to the '93 data verified this trend. Interestingly, hams and loins averaged 3-4 lb. heavier in 2003 compared to 1993, while Boston butt and belly weights were relatively unchanged.

The distribution of ham, loin, Boston butt and belly wholesale cut weights is shown in Table 4. Average weights for each of the wholesale cuts were: ham, 26 lb.; loin, 20.9 lb.; Boston butt, 6 lb.; and belly, 15 lb.

From a meat quality perspective, the audit reported an increase in PSE (pale, soft, exudative) pork. In 1993, 10.2% of the pork was PSE, compared to 15.5% in 2003. Reinforcing the trend, pork exhibiting normal quality characteristics — color/firmness and structure — dropped from 86% in 1993, to 82.6% in the current report. The amount of DFD (dark, firm, dry) pork was cut in half, from 3.8% to 1.9% in 2003.

Table 3. National Pork Benchmarking Audit Estimate of Percentage of Muscle in Carcasses of U.S. Market Hogs
% Muscle range Carcasses with muscle percentages in this range, % Minimum Maximum
Below 45 0.7 0.0 3.0
45 - 47.9 2.0 0.0 6.0
48 - 50.9 8.1 0.0 20.0
51 - 53.9 25.9 11.0 79.0
54 - 56.9 63.0 12.1 88.0
57 and over 0.3 1.0 1.0

“This suggests that as the composition of the market hog has become leaner, management of the leaner animals must be altered to ensure normal pork characteristics,” McKeith says. Packers and purveyors indicated that weather (season) had the largest impact on the occurrence of PSE in carcasses and wholesale cuts.

Table 4. National Pork Benchmarking Audit Estimate of Weights of Wholesale Cuts from Carcasses of U.S. Market Hogs
Weight range, lb. Percentage of carcasses with wholesale cuts in this weight range Minimum Maximum
Below 14.0 0.0 0.0 0.0
14.0 - 17.0 0.6 0.0 5.0
17.0 - 21.8 7.8 3.0 35.0
21.8 - 25.0 25.4 15.0 49.0
25.1 - 27.0 5.8 13.0 66.0
Above 27.0 20.4 0.0 32.0
Below 19.0 26.0 5.0 60.0
19.0 - 23.0 53.5 26.0 80.0
Above 23.0 20.5 0.0 50.0
Boston Butt
Below 4.0 1.2 0.0 9.0
4.0 - 8.0 59.0 30.0 100.0
Above 8.0 39.8 0.0 65.0
Below 10.0 2.8 0.0 15.0
10.0 - 12.0 7.2 2.0 53.0
12.0 - 14.0 14.1 5.0 29.0
14.0 - 16.0 26.7 2.0 42.0
16.0 - 18.0 25.5 0.0 42.0
18.0 - 20.0 14.5 0.0 25.0
20.0 - 25.0 7.8 0.0 25.0
Above 25.0 1.4 0.0 6.0

Carcass Condemnations

Whole or partial condemnations represented 0.4% and 2%, respectively. In other words, 340,000 whole carcasses were condemned, while 1.95 million carcasses were assessed partial condemnation. “The partial condemnations does not include all trimming conducted on the carcass,” McKeith explains. “Rather, it represents times when substantial sections are removed from the carcass.”

The total condemnations, whole or partial, represented approximately 2.3 million animals. Animals or carcasses reported condemned for disease represented 52% of the total. Diseases such as erysipelas, metritis and septicemia were represented, but not all inclusively. The “diseased” segment accounted for the equivalent of approximately one million market hogs or 1% of the total annual slaughter.

Abscesses were the next largest source of condemnation at 9.3%, which was down from 11.1% in the '93 survey.

Arthritis, bruising and skin problems were responsible for about 19% of condemnations (7.5%, 6.5% and 5.1%, respectively).

Carcass Loss Summary

The dollar value loss for carcass nonconformities reported in the 2003 audit averaged $8.08/carcass. That compares to $9.88/carcass in 1993's audit.

The largest losses, $1.32, were attributed to inconsistent weights — which encompassed live, carcass and wholesale cut weights. Thin bellies ranked next for economic losses, averaging $1/carcass. PSE was the third most prevalent problem, costing 90¢/carcass, because of increased purge losses in fresh pork and decreased protein functionality in processed products. And, even though market hog composition had changed considerably, an 85¢ penalty was waged against the average carcass for being too fat. Most of this excess appeared in the shoulder and ham. And, it is noteworthy that an average 57¢ was lost per carcass because of abscesses/injection sites.

Copies of the complete “Benchmarking Value in the Pork Supply Chain” report are available for $75/copy from the American Meat Science Association. Call (217)356-5368 or e-mail:

Something Fishy in Sow Diets

European pork producers have a swine ration component that gives them a nutritional advantage — the availability of fish oil.

There may not be a huge amount of data, but it looks like pigs can benefit from omega-3 fatty acids, much like people do. It's not just any fatty acid, however, that gets credit for a positive response.

“The long-chain carbon fatty acids found in marine oils are the focus,” says John Rooke, a swine nutritionist with the Scottish Agricultural College. Those of particular interest are linolenic, eicosapentaenoic (EPA) and docosahexaenoic (DHA).

Tuna is the best source of the more valuable EPA and DHA fatty acids, but it is not cost effective. So salmon, menhaden and mackerel oil provide those desirable long-chain acids.

According to Rooke, there are about eight products on the market that contain marine oil. Only one, Fertilium (see sidebar), is available in the U.S.

The Scottish scientist spoke on the use of long-chain fatty acids in sow diets during the Minnesota Nutrition Conference last fall in St. Paul, MN. His studies have centered on gestating sows and the effects of specific fatty acids on preweaning death loss.

Rooke has found that feeding salmon oil from Day 60 of gestation through farrowing increased the weight of brain tissue. Whether or not that accounts for the noticeable improvement in viability, he's not sure.

But preweaning mortality dropped significantly from 11.7% to 10.2% in a large commercial study, mostly due to fewer pigs being crushed. The progeny of sows fed fish oil were lighter at birth, but there was no difference in weaning weights.

Most neonatal growth occurs after Day 60, and this is when long-chain fatty acids transfer to the organs, including the brain, is most likely to occur, says Rooke.

Like most mammals, the lipids of brain, retina and spermatozoa in the pig contain substantially higher proportions of 22:6 n-3 (DHA) than other tissues. Most deposition of DHA occurs during late pregnancy, and experimental models have shown that a deficiency at that time causes changes in brain function in the offspring. Thus, improving the omega-3 status of the brain in a fetal pig may improve neonatal vitality, he points out. Increasing the DHA content of spermatozoa has also been associated with improved sperm function and ability to fertilize.

There are well-documented effects of fatty acids on gene expression as well, Rooke notes. This is a rapidly developing area of research and the number of factors regulated by fatty acids is increasing.

Flaxseed as a Source

Cereal grains contain only small amounts of omega-3 acids, and so pig diets using cereal grains and common protein supplements normally have omega-6 to omega-3 ratios greater than 10 to 1, which are considered imbalanced in human nutrition. Only flaxseed provides a supply of omega-3 fatty acids, but not the longer chain acids found in fish oils.

“Flaxseed oil is a very good source of linoleic acid, and it will reduce the ratio of omega-6 to omega-3 acids in the diet to nearer the desirable range of 4 to 8:1. But we need to be careful about whole flaxseed and attributing responses only to the 18:3 n-3 (omega-3), as there may be undefined trace components in the flaxseed that contribute to responses,” says Rooke.

“The 18:3 n-3 fatty acids in flaxseed will convert to EPA, and to a lesser extent to DHA, but the pig does not do this efficiently. The question is: Is the extent of the conversion sufficient to meet requirements? Our data says no,” he adds.

It is also important that the correct amounts are fed. Rooke explored an optimum by feeding sows increasing levels of fish oil from Day 60 and measuring response by changes in brain weight and fatty acid composition. The optimum inclusion, he says, was 10 g. oil/kg. (2.2 lb.) of diet, which corresponded to 6 g./sow/day of EPA and DHA together (total intake 5.5 lb./day), or 0.6% DE intake. On cost grounds, he recommends feeding 1%, or about $5/sow/year.

Rooke points out that given the highly polyunsaturated nature of marine oils and their susceptibility to oxidation, it is notable that marine oils contain varying concentrations of the antioxidant vitamin E.

In the United Kingdom, vitamin E is added to stabilize the oil. “This may have been overkill, as vitamin E levels this side of the pond (U.S.) are usually around two times the requirement. In products such as Fertilium, the encapsulation process protects the fatty acids from oxidation and makes them easier to handle,” he notes.

Many mills simply spray the oils onto product to act as a binder. “In the long run, the practicality and ease of handling with solid products and protection from oxidation may well turn out to be the method of choice for delivering fish oils into feed,” Rooke says. “It also takes the risk away from the mill or unit actually producing the diet.”

In conclusion, the Scottish nutritionist says there is evidence that piglet survival and growth may benefit from including a source of long-chain fatty acids in sow diets. The amount and type of fatty acid to be included, both during ovulation and early pregnancy and during the time of rapid fetal tissue deposition, require further study.

Fatty Acid Terminology Explained

Chemically, omega-3 fatty acids are long chains of carbon atoms (18 to 22), with three to six double bonds (unsaturation sites) in the chain. The “omega” carbon refers to the final carbon at the end of the fatty acid's carbon chain. This carbon is usually designated as the “n” carbon.

Thus, omega-3 fatty acids (n-3) contain their first double bond at the third carbon, while omega-6 fatty acids (n-6) have their first double bond at the sixth carbon atom in the chain. The terms long-chain and short-chain omega-3 fatty acids generally refer to EPA/DHA and alpha-linolenic acid, respectively. Generally, the oilier the fish, the more omega-3 fatty acids are present.

Sow Product Made from Marine Oil

United Feeds Inc. developed and markets Fertilium, a dried, processed blend of omega-3 fatty acids, protein, vitamins and minerals. The source of its marine-derived oil is proprietary, and the encapsulation process to stabilize the fatty acids is patent pending, but the product does contain the long-chain fatty acids eicosapentaenoic (EPA) and docosahexaenoic (DHA).

Company field trials have shown an increase of 0.6 pigs/litter from sows fed Fertilium for 28 days, from farrowing through breeding. It is normally added to the lactation diet and top-dressed during breeding. The product should be used within four weeks of delivery. Fertilium replaces 15 lb. of corn and 15 lb. of soybean meal/ton. Sows should receive 3 oz./day. The cost is about $5/sow/lactation.

There can be problems with implementation, admits Steve Webel, director of reproduction research and development. “We know (feeding for) four weeks is required prior to breeding to get maximum effect. Some farms may not be able to take advantage of the product's benefits because of early weaning. If the lactation and rebreeding period is less than 28 days, sows would need to be fed prior to entry into the farrowing room. Our ongoing research is directed at developing a second-generation product in a program that is more convenient to implement.”

Fertilium helps to balance the omega-6 to omega-3 fatty acids in a proper ratio. “Human nutritionists suggest we consume diets that have a 5:1 ratio,” explains Webel. “A typical sow diet has a ratio greater than 20 to 1, since corn is high in omega-6. Fertilium reduces the ratio to less than 10:1.”