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Articles from 2005 In December

The Year in Review

Those of you who saw my review of the December Hogs and Pigs Report quickly gathered that I don’t think much has changed since last quarter. For that matter, as I write the semi-required “year in review” piece for 2005, I get the same feeling – not much has changed.

Consider that one year ago, the North American pork industry looked back in some degree of amazement at how good hog prices had been (especially in the fourth quarter), then looked ahead with a great degree of trepidation, knowing full well what high hog prices have meant in years past.

I think I can say virtually the same thing today. While hog prices haven’t been nearly as good in 2005, they have held in there pretty well, especially in the fourth quarter when many of us felt we would see red ink for average producers. In addition, my skepticism of the December Hogs and Pigs Report is due to what high prices have caused in the past. Now, with two years of good prices, my skepticism hasn’t been alleviated.

There is scant evidence of rapidly growing supplies. Yes, I think hog slaughter will grow in 2006 and I think weights will add to that growth to provide 2-3% more pork. But that can hardly be classified a pell-mell expansion or irrational exuberance. In a pork market that is highly sensitive to quantity, that growth may be enough to cause some red ink, but I don’t see a disaster – barring any unforeseen circumstances.

U.S.-Canadian Relations
In January 2005, Canada and the U.S. were at odds over trade – in pigs. As January 2006 dawns, the two countries are now at odds over trade, this time in corn. And the wind sown by tariffs on corn could reap a whirlwind of trade issues regarding pigs and cattle.

Driving up Canadian grain prices relative to those of the U.S. will no doubt provide huge incentives to feed pigs and cattle in the U.S. Now we hear that the Canadian Border Services Agency has a plan to compensate Canadian feeders for the tariffs charged on imported corn. And further, as I understand it, that compensation will only be paid if those animals are shipped to the U.S. I don’t know many details of the program, but that seems to provide an additional incentive to ship slaughter animals south as well.

Should this action result in a flood of pigs into the U.S., do not be surprised if U.S. pork producers file another trade action. And this one could be more successful. Canada will not have a significantly weaker dollar to credit for its increased exports. The U.S. will have the clear issue of Canadian trade action and, perhaps, direct subsidies not generally available to all producers. The economic times will not be nearly so good, thus making the case for injury a much easier one.

This is playing out like Greek tragedy. Bad things are happening and everyone claims that they have no power to stop them. It’s time for leadership in both Canada and the United States. Subsidized U.S. grain, protected Canadian sectors, and risk reducing whole farm income supplements – you can’t give people money without affecting their behavior. Something has to give if this continent is to maintain its competitive position in the world pork market.

The late Jerry Clower, the country sage of Yazoo City, MS, used to tell the story of the time his friend John climbed a tree to knock out a ’coon (that’s a raccoon for those of you not from the South) only to find that it was not a ’coon, but a lynx. During the subsequent melee’ high up in the tree, Jerry and the others on the ground kept yelling “Knock him out, John!” to which John finally replied, “Just shoot up here amongst us ’cause one of us has to have some relief!”

Let’s hope it doesn’t come to that between the Americans and the Canadians. We all have too many friends across the border to take that chance.

Thank you so much for reading North American Preview. I received many kind comments this year and, just as important, a good number of critical comments – usually offered in a very positive manner. I appreciate both and urge you to continue to communicate with us.

May 2006 be a happy, blessed and prosperous New Year for you and those you love!

Click to view graphs.

Steve R. Meyer, Ph.D.
Paragon Economics, Inc.

2005 Swine Research Review - Animal Welfare

Animal Wellfare

Crowding Reduces Performance, Welfare Of Grow-Finish Pigs

Grow-finish pigs allocated more space, grew faster and exhibited better welfare characteristics and lower injury scores than groups in crowded conditions.

Both performance and welfare indicators were employed in a study at the University of Minnesota, funded by the Pork Checkoff. The study calculated the space allowance for grow-finish pigs using an allometric formula that weighs the size, shape and space utilization behavior of pigs.

Groups of 19 grow-finish barrows were evaluated at four levels of fully-slotted floor space: 6.9 sq. ft./pig, 8.0 sq. ft. /pig, 8.7 sq. ft./pig and 9.5 sq. ft./pig.

Pigs allocated 6.9 sq. ft./pig had lower average gain than those pigs allocated higher space allowances. The performance and welfare of the groups on higher space allowances were comparable in achieving a final slaughter weight of 256 lb. as depicted in Table 1.

Pen efficiencies (daily gain/unit of floor space) were similar across space allowance treatments during the final three weeks.

Grow-finish pigs were either sorted by size at placement or left in varying weight groups (Table 1). Sorting doesn’t appear to provide any benefits to average daily gain or overall welfare. But pigs in the varying weight groups spent more time lying in preferred areas than pigs in the uniform weight group.

Welfare of pigs appeared to be adversely affected at stocking densities of 6.9 sq. ft./pig, based on behavioral observations (increased aggression) and higher total injury levels. Salivary stress hormone levels did not differ with space allowance treatments.

Researchers: Leena Anil, DVM; Sukumarannair S. Anil, DVM; and John Deen, DVM, University of Minnesota. Contact Leena Anil by phone (612) 625-4243, fax (612) 625-1210 or e-mail .

Floor Space Plays Major Role in Hog Transport Losses

Many factors including genetics, health status, diet, handling intensity and facility design play a part in transport losses at the packing plant.

Increasing floor space during transport from 4.20 to 5.17 sq. ft./pig produced significant reductions in the incidence of total non-ambulatory pigs (0.62% vs. 0.27%); the incidence of non-ambulatory, non-injured pigs (0.52% vs. 0.15%); and the overall incidence of transport losses (0.88% vs. 0.36%).

That data is based on 74 loads of finishing pigs from wean-to-finish barns on two farms within one production system. Two different designs of straight, double-deck trailers were used for pig handling and transportation at 4.20 and 5.17 sq. ft./pig.

Variables measured in this study included the incidence of non-ambulatory pigs at the farm during loading and at the plant, average load weight, load number within each day, event times, and temperature and relative humidity in the trailer from loading to unloading.

Increasing floor space during transport greatly reduced the number of deads and non-ambulatory pigs at the plant. However, increasing floor space from 4.20 sq. ft./pig to 5.17 sq. ft./pig reduced numbers per load from 192 to 154, respectively.

“We also found that transport times and conditions may impact losses at the plant,” says Mike Ellis, professor of animal science, University of Illinois. “The incidence of non-ambulatory pigs at the farm increased as relative humidity during loading increased, and the number of trailers loaded by the same crew within a day increased.

“The overall incidence of transport losses at the plant increased as waiting and unloading time at the plant increased, and as the total transport time increased,” reports Ellis.

Average trailer temperature during transport and average pig weight on the trailer were unrelated to losses.

Researchers: M.J. Ritter, M. Ellis, J.M. DeDecker, M.E. Kocher, B.A. Peterson and J.M. Schlipf, University of Illinois; J. Brinkmann and B.F. Wolter, The Maschhoffs, Inc.; and K.K. Keffaber, DVM, Elanco Animal Health. Contact Ellis by phone (217) 333-6455, fax (217) 333-7861, or e-mail

Dynamic Group-Housed Sows Experience More Injuries, Aggression

Frequently mixed sows in group-housing systems featuring electronic sow feeders (ESF) incurred higher total injury scores (TIS) and compromised welfare vs. sows mixed twice or in static groups.

A Pork Checkoff-funded project at the University of Minnesota evaluated the effect of group size and structure on the welfare and production performance of gestating sows. In the study, three group-sow housing systems with ESF were established:

  • For the dynamic group, two adjacent pens of 50 sows were combined one month before the start of the experiment. The first batch of “experimental sows” was added to this 41.8 x 44.3-ft. combined pen with two ESF’s and six water bowls five days after breeding. At that time, another batch of sows in late gestation from the combined pen was moved to farrowing stalls.
    The next batch of sows was added 14 days later upon removal of another batch of sows in late gestation. This process was continued until the fourth batch of sows was added.
    The four batches of sows were kept together until the first batch of experimental sows was moved to farrowing stalls, and another new batch of sows was added to maintain group size. This process continued until all four batches were removed from the pen.
  • For the twice-mixed group, the first batch of weaned sows was mixed in 41.8 x 22.1-ft. pens five days after breeding, and the second batch was mixed 14 days later. A second, twice-mixed group was formed and similarly maintained.
  • One batch of a static group of sows was housed in one half of a 41.8 x 22-ft. pen, fed by a single ESF. Three other batches of sows were similarly penned.
    The results of the three groups of sows presented in Table 1 show no differences in terms of welfare indicators, such as cortisol concentrations, and the number of total aggressive interactions.
    But total injury scores were higher, and the number of non-aggressive interactions was lower in the dynamically group-housed sows, suggesting that the welfare of frequently mixed sows was compromised compared to the other groups.

Production performance was similar amongst all three group-housing situations.

Researchers: Leena Anil, DVM; Sukumarannair S. Anil, DVM; and John Deen, DVM, all of the University of Minnesota; and Samuel Baidoo and Roger Walker, Southern Research and Outreach Center, University of Minnesota-Waseca. Contact Leena Anil by phone (612) 625-4243, fax (612) 625-1210 or e-mail

Diet Changes Don’t Slow Stereotypic Behavior in Gestating Sows

Individual stall housing and feed restriction during gestation increase the incidence of stereotypic behavior by gestating sows. Activities include bar biting, sham chewing, and nosing or licking the floor or feeder when feed is not present.

Diets featuring 35% to 80% fibrous ingredients, particularly beet pulp, can greatly lower the incidence of stereotypic behavior during gestation. However, these high-fiber diets won’t flow through mechanical feeding systems.

Researchers at the University of Minnesota at Morris placed 239 second-parity and older sows on either a typical corn-soybean meal (control) diet at 4.7 lb./day, or a corn-soybean meal diet containing 40% soybean hulls fed at 5.7 lb./day. The higher feeding level for the fiber diet was necessary to compensate for the lower energy density of the fiber diet compared to the control diet.

Half of the control-fed sows and half of the fiber-fed sows were given their complete daily feed allotment at 7:30 a.m. (1X), while the other half were fed their daily feed allotment in two, equally-sized meals at 7:30 a.m. and at 2:30 p.m. (2X), throughout gestation.

On Days 40 and 80 of gestation, a subset of sows assigned to each feeding regimen was videotaped for 24 hours to observe the occurrence of stereotypic behavior (Figure 1). The taping confirmed that inclusion of 40% soybean hulls in a corn-soybean meal diet didn’t reduce the occurrence of stereotypic behaviors in gestating sows.

One reason for the development of stereotypic behavior is feed restriction imposed on sows that leaves them feeling hungry for long periods of time. High-fiber diets can provide sows with additional quantities of feed to offset hunger without gaining excessive condition.

But in this experiment, one additional pound of feed containing soy hulls was not enough to decrease stereotypic behavior. Another diet source with different fiber characteristics may be more effective. Feeding sows twice compared to once daily didn’t significantly impact the level of stereotypic behavior.

Researchers: Jonathon Holt and Lee Johnston, University of Minnesota-Morris; and Sam Baidoo and Jerry Shurson, University of Minnesota-St. Paul. Contact Johnston by phone (320) 589-1711, fax (320) 589-4870 or e-mail

2005 Swine Research Review - Pork Quality

Pork Quality

Improved Carcass Chilling Enhances Pork Quality

Subtle differences in the harvest process have the potential to improve fresh pork color and water-holding capacity.

In a study at the Iowa State Meats Laboratory, reducing scalding time from 7.6 to 5.6 minutes expedited the start of carcass chilling, and produced a slightly lower loin temperature two hours postmortem and a higher loin pH.

The end result was an improvement in pork color and water-holding capacity.

Loins from 64 pork carcasses were selected for quality evaluation immediately after fabrication one day postmortem. Fresh pork color, firmness, drip loss, pH and temperature were measured. Samples from 40 pork loins were evaluated five days postmortem for purge loss, color, pH and texture.

The more rapid scald treatment reduced the time on the processing floor by about 5 minutes. The 5.6-minute scald treatment also consistently produced lower Minolta L values (indicating darker pork) and pork loin chops with lower hue angle values (indicating less discoloration).

Those observations were confirmed by results from the quality evaluation five days postmortem.

Drip loss was also significantly lower in loins from carcasses in the 5.6-minute scald group. Shorter scalding produced a higher pH after the initial chilling period of two hours postmortem.

However, scald duration did not affect purge loss in vacuum bags during a five-day storage period.

Results show that small but significant improvements in the consistency of fresh pork can be achieved by altering slaughter processes.

Researchers: G. Mendez, E. Huff-Lonergan and S.M. Lonergan, Iowa State University. Contact S.M. Lonergan by phone (515) 294-9126, fax (515) 294-5066 or e-mail

Risk of Toxoplasma Infection Evaluated in Retail Meat Products

Representative blood samples from the National Health and Nutrition Examination Survey indicate that 22.5% of the U.S. population ages 12 and over are infected with Toxoplasma gondii (T. gondii).

This single-cell parasite causes mental retardation, loss of vision and other congenital health problems in humans. It is also an important cause of death and illness in immunosuppressed individuals.

In addition to congenital transmission, there are two other modes of transmission of T. gondii. People become infected by eating food or drinking water contaminated with oocysts excreted by infected cats, or by eating uncooked meat containing tissue cysts of T. gondii.

Scientists at the Beltsville Agri­cultural Research Center (BARC) in Beltsville, MD, and the Centers for Disease Control (CDC) in Atlanta, GA, conducted a survey of the prevalence of T. gondii in 6,282 samples of pork, beef and chicken (2,094 samples each) in 698 retail stores from 28 regions across the United States. Each sample purchased from the meat case was at least 2.2 lb.

Pork was the only meat found to contain viable T. gondii tissue cysts; viable Toxoplasma parasites were detected in eight samples.

Overall, the prevalence of viable T. gondii in retail meat was low. The BARC/CDC survey suggested that the actual risk of someone buying meat contaminated with T. gondii was 38% per decade. Over a 10-year period, if 100 people across the nation purchased pork from the retail meat case, 38 of them would have purchased meat containing T. gondii tissue cysts. In the northeastern United States, where the prevalence in pork is higher, 78 of the 100 would have purchased infected pork.

The researchers concluded that the risk of acquiring contaminated meat, as determined by their meat-case survey, is far too low to explain the source of most of the T. gondii infections in the United States.

They noted other factors must be responsible for human infection, including other types and cuts of meat, exposure to soil contaminated with cat feces and unfiltered water.

Researchers warned consumers, especially pregnant women, to be aware they still could acquire T. gondii from ingestion of undercooked meat, particularly pork.

Cooking meat to an internal temperature of 151° F. kills T. gondii. Post-harvest processing techniques, such as hard chilling and pumping, also kill T. gondii tissue cysts.

Researcher: Dolores Hill, U.S. Department of Agriculture, Agricultural Research Service, Beltsville Agricultural Research Center. Contact Hill by phone (301) 504-8770 or (301) 504-8300, fax (301) 504-6273, or e-mail

2005 Swine Research Review - Genetics/Reproduction


Genetic Pathways to Reduce Phosphorus Excretion Studied

Environmental Protection Agency regulations restricting the amount of phosphorus (P) that can be applied to the land have researchers examining ways of reducing P dietary supplementation to swine as well as minimizing the excretion of P.

To reduce P excretion while maintaining animal performance, researchers have studied the requirements for different genotypes and management conditions, plus ways of improving the bioavailability of P through plant sources.

Iowa State University researchers are focusing on the underlying genetic mechanisms behind P utilization and the impact it could have on commercial pork production. Limited research is available on the effects of P nutrition on gene expression in non-agricultural animals, and only a few genes have been studied previously.

Iowa State researchers examined the effects of P nutrition on large-scale gene expression in pigs from two different sire lines – one selected specifically for meat quality, the other for growth rate.

Microarray analysis showed sire treatment effects in gene expression in both liver and muscle tissue. Sire x treatment effects were noted in the expression of genes known to affect bone marrow.

Researchers noted, after only two weeks on the experimental diets, significant sire effects on bone strength and ash percentage. Sire x treatment effects were also seen for average daily gain and feed conversion. However, traditional plasma indicators of P levels, inorganic P concentration and alkaline phosphatase activity did not show any sire or sire x treatment effects, they reported.

Future work will focus on identifying new gene targets for better P utilization and markers for genotype-specific P requirements. The goal is to enable genetic selection of pigs that require less P and excrete less P, and identification of genetic lines to match producers’ waste management strategies.

Researchers: A. Qu, L. Hittmeier, L. Grapes, M.F. Rothschild and Chad Stahl, Iowa State University. Contact Stahl at (515) 294-5990 or e-mail

AI Timing Studied

Timing for artificial insemination (AI) is commonly based on expressions of estrus. Success with AI is largely reliant on the heat-check boars’ abilities to stimulate these expressions of estrus and the breeding technicians’ abilities to recognize them.

However, wean-to-estrus and estrus-to-ovulation intervals are variable. Both are influenced by other factors, such as follicle size, season, parity and lactation length. Researchers at the University of Illinois chose to focus on wean-to-ovulation interval, noting it has not been studied extensively and could be less variable.

If the factors influencing wean-to-ovulation intervals can be more accurately identified, a fixed-timed AI procedure could be developed, and the costs and labor of estrous detection could be eliminated, they speculated.

In an effort to characterize the factors influencing wean-to-ovulation interval, researchers performed a retrospective analysis from eight studies between 1998 and 2005. Sows were divided into two groups – 136 sows that received PG600 at weaning (PGW), and 650 sows that received no treatment at weaning (NOW).

Researchers found little variation in the wean-to-ovulation interval, with most sows ovulating within six days after weaning (6.0 +/- 0.9 days); 85% of sows ovulated within a 36-hour period between Day 5 and Day 6.5. Only 5% of sows ovulated on Days 2 to 4.5. Ten percent ovulated between Days 7 and 10 after weaning (Figure 1).

Wean-to-estrus and wean-to-ovulation intervals were inversely related. As wean-to-estrus inter val increased, wean-to-ovulation interval shortened, researchers reported. Regardless of the wean-to-estrus interval, most sows ovulated within a similar interval from weaning.

Looking closer, researchers found the PGW treatment advanced the wean-to-ovulation interval by more than half a day, and increased the proportion of sows ovulating closer to weaning when compared to the NOW sows (Figure 2). In other words, more of the PGW-treated sows ovulated earlier. Previous studies indicated that about 10% more PGW sows express estrus and ovulate within seven days of weaning. Therefore, insemination times for PGW sows should be altered.

Season and parity did not influence wean-to-ovulation, they noted. However, when lactation length extended beyond 18 days, wean-to-ovulation interval was shorter than sows that nursed less than 18 days.

Researchers concluded it would be difficult to breed 85% of sows within 24 hours before ovulation using a fixed-time insemination procedure. In particular, if single insemination were practiced, those sows ovulating early or late from the norm would likely miss the preferred 24-hour insemination window.

Double insemination would cover a greater percentage of sows ovulating, but would undoubtedly allow for late inseminations of the early-ovulating sows. Late inseminations reportedly cause some reproductive problems.

Likewise, increasing the number of inseminations or shortening the interval between inseminations may be detrimental to conception rates and litter size. In other words, fixed-time inseminations could risk failure due to early- or late-ovulating sows.

Semen extenders or techniques that allow sperm to survive longer within the sow’s reproductive tract, or hormonal treatments that reduce variation in ovulation time, could remedy these concerns.

Researchers agree that further investigation is necessary to refine insemination-timing procedures.

Researchers: S.M. Breen and R.V. Knox, Department of Animal Sciences, University of Illinois. Contact Knox at (217) 244-5177 or e-mail

Genetic Resistance To PRRS Virus Studied

The most important disease affecting U.S. pork production is porcine reproductive and respiratory syndrome (PRRS). With losses estimated at nearly $600 million annually, the identification of genetically-resistant breeding stock would be a significant advancement in controlling the disease.

Work conducted at the University of Nebraska, led by Rodger Johnson, has proven that genetic variation in resistance to PRRS virus infection exists. In a recent manuscript, Johnson’s group reported differences in responses to PRRS virus infection in two genetic lines of pigs.

Pigs from the Nebraska Index line (NEI), selected 20 generations for litter size, and commercial Hampshire-Duroc cross pigs (HD), selected for lean growth, were compared for responses to PRRS virus infection.

At 26 days of age, pigs were infected intranasally with PRRS virus. Viral load (viremia); weight; and rectal temperature at 0, 4, 7, and 14 days post-infection (dpi) were recorded for PRRS-infected and litter-matched control pigs. Lung, bronchial lymph node, and blood were collected at necropsy (14 dpi).

Infected NEI pigs had greater weight gain, decreased viremia, and decreased clinical signs than infected HD pigs. D.B. Petry and his colleagues concluded that line differences, and line by treatment (infection) interactions across days, indicate genetic variation in responses to PRRS virus. Overall, NEI pigs were more resistant to PRRS virus than HD pigs.

Researchers then used principal component analyses to rank pigs for phenotypic response to PRRS virus. Pigs were classed either as low (L) responders (low viremia, few lung lesions, and high weight change) and high (H) responders (high viremia, many lesions, low weight change).

Infected (+) low-responder NEI pigs (LNEI+) had the lowest viremia at day 14 (Table 1), low clinical signs in their lungs, and greater weight gain than high responder NEI pigs (HNEI+) and either low- or high-responder HD pigs (LHD+ or HHD+).

If underlying genetic variation determines whether pigs will effectively limit virus replication after infection with PRRS virus, the next challenge is identifying the genes involved.

Likely targets for control of most viral infections are immune genes (Table 2). There are innate immune factors, those that react immediately to infections but are non-specific. Most viruses require more specific responses, such as interferon-gamma (IFNG) related genes, termed T helper 1 (Th1) genes.

Alternately, some viruses decrease the host immune response by stimulating regulatory T cell genes, such as interleukin-10 (IL10), that can turn off immune responses.

To evaluate the role of these immune genes, a collaboration funded by the USDA PRRS Coordinated Agricultural Project (PRRS-CAP) grant was established between Nebraska scientists and Joan Lunney’s lab at the USDA’s Beltsville Agricultural Research Center.

For these immune gene studies, RNA was prepared from frozen lung and lymph node tissue of seven pigs in each group: LNEI+, HNEI+, LHD+, HHD+, and their control littermates; cDNA expression of the 12 genes noted in Table 2 was performed and data were statistically evaluated.

Overall, HD pigs had greater magnitude of difference in expression of immune genes in their lung and lymph node tissue at 14 dpi than NEI pigs. To confirm these results, serum protein levels of a subset of the Table 2 immune markers were tested. These tests affirmed the lung gene expression differences.

Thus, following PRRS virus infection, low expression of IFNG in cDNA and in serum were correlated with resistance. This low IFNG, along with low serum antibodies, is the opposite of what might be expected. One might predict that a “better” immune response would produce higher levels of IFNG and antibodies. But PRRS virus-resistant pigs had lower levels of IFNG and antibodies.

An additional immune marker was identified: PRRS virus-resistant pigs had high pre-infection serum levels of the innate cytokine interleukin-8 (IL8). This suggests that pre-activation of the innate immune system may help to prevent viral expansion.

These data outline targets for future studies of genetic association, to determine if specific immune gene alleles are associated with PRRS virus resistance. Such studies will help determine the actual causative alleles, thus enabling producers to decrease breeding of PRRS-susceptible pigs, and specifically select for PRRS-resistant stock.

Because of the likely involvement of important immune genes, it will be essential to determine whether PRRS-resistance alleles are also associated with resistance to other viral infections.

Researchers: Rodger Johnson, University of Nebraska, Lincoln, NE; Derek Petry, Monsanto Choice Genetics, St. Louis, MO; Joan K. Lunney, Animal Parasitic Diseases Laboratory, ANRI, ARS, USDA, Beltsville, MD. Contact Lunney at (301) 504-9368 or e-mail

Pork Checkoff Funds Two Swine Welfare Projects

The National Pork Board announced two newly-funded swine welfare projects covering pig handling and transport issues, says Sherrie Niekamp, new director of animal welfare for the Pork Board.

The one-year projects focus on the fatigued pig syndrome, which imposes an animal welfare and economic concern to everyone in the pork production chain, says Niekamp. The projects include:

  • “Comparison of Handling Attributes and Physiological Indicators of Stress and Welfare During Marketing of Pigs from Conventional Small Pens and Large Pen Auto-Sort Systems,” Prairie Swine Centre, Saskatchewan, Canada, and

  • “The Development of Improved Trailer Designs and Transport Management Practices to Create the Optimum Environment for Market Weight Pigs During Transport and Minimize Transport Loss,” University of Illinois.

The studies aim to provide some information on the causes of fatigued finisher pigs at marketing time and provide solutions to reduce the incidence, says Niekamp.

Fatigued pigs are animals that have temporarily lost the ability or desire to walk, but have a reasonable expectation to recover full locomotion with rest, she explains.

Feral Swine Raise PRV Concerns

Although no domestic herds are infected with pseudorabies (PRV) in the United States, four cases of infection were found in feral swine in 2005, it was reported at the U.S. Animal Health Association annual meeting last month in Hershey, PA.

Infected feral swine were detected in Louisiana and Arizona; all were destroyed and no hogs remain on the farms.

product news

Heat Lamp Controller

RetroLite Corporation introduces the Comfort Zone 20 Power Control. The new controller can be used independently to adjust the heat output of two heat lamp fixtures. Each controller takes a standard 175-watt bulb, which allows it to be operated at 175, 125 or 100 watts, thus saving energy and allowing quicker temperature adjustment for piglets. The power controller allows the same lamp to be used in summer and winter, which reduces the need for frequent changes in fixture height.
(Circle Reply Card No. 101)

New Corn Hybrids

Pioneer Hi-Bred International, Inc. announces the release of 62 new Pioneer brand corn hybrids for the 2006 planting season. The list includes nine new genetic families with 34 hybrids containing technology from the Herculex family of insect control, and 28 new hybrids containing the Roundup Ready Corn 2 trait. The Herculex family offers three insect protection options for growers. Twenty-three new hybrids will contain the Herculex I trait for above-ground insect protection. Eleven new hybrids will contain the Herculex RW gene for transgenic corn rootworm control. The Herculex I gene protects the corn plant against European and southwestern corn borer, western bean cutworm, black cutworm, fall armyworm, corn earworm, sugarcane borer, southern cornstalk borer and lesser cornstalk borer, while the Herculex RW trait protects against western, northern and Mexican corn rootworms. In 2005, hybrids with Herculex RW and Herculex XTRA, a combination of Herculex I and Herculex RW traits, were tested by Pioneer for yield and efficacy against larval corn rootworm feeding. In normal growing conditions, the effectiveness of Herculex RW in controlling feeding was equal to that of insecticides.
(Circle Reply Card No. 102)

Protective Lotion

Skin MD Natural is a new “shielding lotion” from 21st Century Formulations. It is perfect for those working with their hands, because it enhances the skin's own natural protection while hydrating the skin. The lotion contains an effective combination of natural ingredients with a moisturizing factor 10 times higher than glycerin, a standard ingredient in skin care products. It is very effective in helping to prevent damage when working with livestock, doing veterinary work, cleaning barns and more. It also helps protect against chemicals, common cleaning products, pesticides and hundreds of other irritants.
(Circle Reply Card No. 103)

Rodent Neurotoxin

Agrisel USA, Inc. offers a unique rodenticide formulation to control rats and mice found in swine confinement units. Designed as a neurotoxin, Gladiator is Environmental Protection Agency-approved for anticoagulant-resistant rodents. The neurotoxin formula, combined with high palatability, kills rodents in a single dose. Traditional anticoagulant rodenticides allow rodents to continue feeding for up to five days, but rodents eating Gladiator die within one to two days, which stops feeding and reproduction cycles more quickly. Because rodents ingest a minimal amount of product, dogs, cats and predators are not affected by ingesting Gladiator-poisoned rodents. The bait also contains Bitrex, an ingredient with a bitter taste that discourages accidental consumption by children.
(Circle Reply Card No. 104)

Chemical Feed Pump

Diemold International, Inc. announces the Gator-XL, a non-electric, water-powered, heavy-duty chemical feed pump. The pump weighs 5½ lb. and will operate at pressures up to 120 psi (lb./sq. in.). The Gator-XL can be utilized in irrigation systems, sanitation applications, water conditioning and animal health — anywhere additives are needed in water. It accurately pumps a variety of chemicals, including fertilizers, disinfectants, chlorine, acids, soaps and pharmaceuticals, with no need for separate pumping units for different chemicals. The Gator-XL can be installed directly to pipes or connected with flexible hoses.
(Circle Reply Card No. 105)

Energy-Efficient Fan

American Coolair Corporation introduces the FGDC fan, which features a new cast-aluminum airfoil blade assembly for superior air performance. The three-bladed prop allows for more regain and faster spinning, which improves energy efficiency, says the company. The fiberglass FGDC is available in 16-in., 20-in., 26-in., and 36-in. sizes. Specially-formed structural components also provide sturdy, yet aerodynamic, support. Variable-speed controls are available to meet the needs of any ventilation situation.
(Circle Reply Card No. 106)

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

USDA Provides ID Grant

The Agriculture Department's Animal and Plant Health Inspection Service will award $3 million in cooperative agreements to states and tribes to develop solutions and automated data collection for the National Animal Identification System (NAIS).

The funds will support research or field trials:

  • To enhance the effectiveness of collecting animal identification (ID) data in production, marketing and slaughter environments;

  • To validate identity when official ID devices are lost or malfunctioning;

  • To conduct economic assessments of animal ID systems in production, marketing and slaughter environments; and

  • To evaluate advanced data collection systems for adaptability and use with NAIS.

The deadline for applications is Dec. 30. Apply at

2005 Swine Research Review - Nutrition


Out-of-Feed Events Impact Pig Performance

Producers are increasingly reducing the fineness of grind in pig rations in an effort to improve feed conversion and overall grow-finish performance.

However, finely ground diets could be producing out-of-feed events, due to bridging of feed in bulk bins and feeders. This can lead to an overall reduction in average daily gain.

Add to this the difficulties in placement and delivery of feed orders from toll mills, and the possibility of many out-of-feed events occurring during the grow-finish phase of production increases.

To test the impact of out-of-feed events, 240, 17-day-old weaned pigs were shipped 200 miles to the University of Nebraska's Haskell Ag Lab in Concord, NE.

On arrival, 15 pigs were placed in each of 16, 8×14-ft., fully slotted pens in a naturally ventilated, wean-to-finish barn, providing 7.5 sq. ft./pig.

Only barrows were placed on test to avoid the influence of gilts urinating in feeders. The experimental treatments began six weeks postweaning and lasted for 109 days (nearly 16 weeks).

Table 1. Impact of Experimental Treatments on Pig Performance
Out of Feeda Particle Sizeb
Item Never Weekly Coarse Medium
No. pens 8 8 8 8
Pig weight, lb.
On test 53.2 51.3 52.3 52.2
Day 53 155.2 145.3 150.9 149.6
Day 109 261.8 251.5 257.6 255.7
Coefficient of variation of pig weight within pen, %
On test 17.4 16.1 16.3 17.3
Day 53 10.7 10.9 10.3 11.3
Day 109 8.1 8.2 7.5 8.8
Daily gain, lb.
On test — Day 53 1.92 1.77 1.86 1.84
Day 53 — Day 109 1.90 1.89 1.91 1.89
Overall 1.91 1.84 1.88 1.87
Daily feed intake, lb.
On test — Day 53 4.42 4.13 4.34 4.21
Day 53 — Day 109 6.57 6.47 6.67 6.36
Overall 5.52 5.33 5.54 5.31
On test — Day 53 2.30 2.33 2.34 2.29
Day 53 — Day 109 3.45 3.41 3.50 3.36
Overall 2.89 2.90 2.94 2.85
Carcass data, Tyson Fresh Meats, Madison, NE
Carcass wt., lb. 206.3 197.5 201.6 202.1
Fat depth, in. 1.02 0.97 0.98 1.00
Loin depth, in. 2.75 2.67 2.72 2.70
Lean, % 53.5 53.5 53.6 53.4
Pigs dead, no. 2 4 2 4
Removed, no. 1 1 0 2
< 205 lb., no. 2 4 2 4
aNever = never out of feed; Weekly = 20 hr-out-of feed on a random day each week.
bCoarse = average 1266 microns; Medium = average 1019 microns.

Four treatment combinations analyzed two nutritional factors: 1) out-of-feed events, never or weekly; and 2) feed particle size, coarse (1,266 microns) or medium (1,019 microns). Out-of-feed events consisted of a 20-hour period starting at 12 noon on a random day each week for the 16-week period.

During the first eight weeks, weekly out-of-feed events reduced average daily gain 0.15 lb./day, compared to the never out-of-feed treatment (Table 1), due to a reduction in daily feed intake. Total gain depression was 7.9 lb. for pigs experiencing weekly out-of-feed events. There was no impact on feed conversion efficiency.

In contrast, out-of-feed events had no effect on daily gain or feed conversion for the second, eight-week period of the experiment.

For the 109-day feeding trial, weekly, random, 20-hour out-of-feed events resulted in a 0.077/lb./day decrease in daily gain and a total loss of 8.4 lb./pig with no effect on feed conversion. Pigs adjusted to being out of feed in the second half of the experiment, though they never compensated for the loss in gain during the first half of the trial.

Decreasing particle size 247 microns (going from coarse to medium) resulted in a 3.1% improvement in overall feed conversion.

The experimental design did not produce any differences in skin lesion scores, a measure of animal welfare and injury from fighting at the feeder.

Also, there was no interaction of out-of-feed events and diet particle size.

“In production units that must sell pigs by a certain date, these data will allow producers to examine whether the improvement in feed conversion efficiency from finely ground diets overcomes the loss in weight gain from out-of-feed events that may be due to increased bridging of finely ground diets,” observes lead researcher Mike Brumm, University of Nebraska.

Researchers: Mike Brumm and Sheri Colgan, research technologist, University of Nebraska Northeast Research and Extension Center, Concord, NE. Contact Brumm by phone (402) 584-3816, fax (402) 584-3859 or e-mail

Sorting by Weight, Bumping Energy Improves Returns

Greater economic returns may be possible by dividing finishing pigs by weight, not sex, and then feeding a targeted, higher energy diet to lighter pigs, according to Kansas State University researchers.

Two studies have shown that adding 6% dietary fat to the lightest 50% of the finishing pig population increased average daily gain (ADG) and reduced the number of lightweight pigs sold. Researchers say by feeding 6% dietary fat to the light pigs and removing fat for heavy pigs, producers could increase profit margins when compared to feeding mixed populations of heavy and light pigs.

Table 1. Effects of Added Fat and Initial Sort on Growth Performance in Grow-Finish Pigs (Exp. 1)a
Main Effects
Fat Addition Weight
Item Fat No Fat Heavy Light Mixed
Average daily gain, lb.
Day 0 to 56 1.59 1.54 1.68 1.48 1.54
Day 56 to 88 1.90 1.83 1.90 1.83 1.85
Day 88 to 109 2.20 2.25 2.29 2.18 2.23
Overall 1.79 1.76 1.83 1.72 1.76
Average daily feed intake, lb.
Day 0 to 56 3.42 3.64 3.88 3.20 3.48
Day 56 to 88 4.98 5.42 5.53 4.92 5.16
Day 88 to 109 5.60 6.22 6.19 5.62 5.86
Overall 4.23 4.59 4.74 4.17 4.39
Day 0 to 56 2.16 2.38 2.33 2.27 2.22
Day 56 to 88 2.70 2.94 2.94 2.70 2.78
Day 88 to 109 2.56 2.78 2.70 2.56 2.63
Overall 2.38 2.63 2.56 2.44 2.50
aA total of 1,032 gilts (24 or 25 pigs/pen and seven pens/treatment) with an initial average weight of 67.7 lb.
Table 2. Effects of Added Fat and Initial Sort on Weight Variation, Carcass Traits, and Economic Value in Grow-Finish Pigs (Exp. 1)a
Main Effects
Fat Addition Weight
Item Fat No Fat Heavy Light Mixed
Weight, lb.
Day 0 67.7 67.8 76.5 59.1 67.7
Day 56 158.4 155.7 172.0 142.9 156.4
Day 88 219.1 215.1 233.6 201.8 216.1
Day 109 262.9 260.1 275.6 248.0 260.8
Weight, CVc
Day 0 12.27 11.87 8.72 11.85 15.65
Day 56 14.56 14.10 12.16 15.21 15.62
Day 88 12.74 11.89 10.23 13.06 13.67
Day 109 11.79 10.99 9.18 12.48 12.50
Average daily gain CV
Day 0 to 56 20.44 20.79 19.18 22.02 20.66
Day 56 to 88 16.55 15.43 14.86 15.76 17.34
Day 88 to 109 19.78 19.76 19.02 19.75 20.54
Overall 14.07 13.28 11.86 14.86 14.31
Carcass Traits
Backfat (mm) 0.57 0.57 0.59 0.56 0.57
Fatfree Lean Index 51.49 51.48 51.58 51.32 51.55
Lean, % 57.22 57.22 56.99 57.36 57.31
Loin Depth, cm 2.40 2.37 2.39 2.37 2.40
Economic Value
FC/lb. Gain, $ 0.168 0.163 0.168 0.159 0.163
Sort discount, $ -2.55 -2.28 -2.57 -2.08 -2.66
MOFb, $ 90.99 91.26 94.92 87.65 90.81
aA total of 1,032 gilts (24 or 25 pigs/pen and seven pens/treatment) with an initial average weight of 67.7 lb.
bMargin Over Feed; calculated using corn $2.16/bu, SBM $186.19, Fat $13.34/cwt, Carcass Base Price $45.39
cCV = Coefficient of Variation

Because U.S. packer matrices impose large discounts for lightweight pigs, any technology or management technique that reduces the number of lightweight pigs could result in a higher net return.

Researchers focused on reducing variation in a group of pigs by increasing growth rate of the lightest pigs, thus shifting this portion of the population to heavier weights. Researchers were striving to determine whether adding dietary fat to the diet of the lightest 50% of the pigs in a finishing barn could increase both ADG and economic return.

The first experiment was conducted with 1,232 gilts with an initial weight of 67.7 lb. The pigs were sorted into weight categories. Pigs were housed in pens of 24-25 pigs/pen. The second experiment included 1,176 gilts sorted by weight with 28 pigs/pen.

Diets were formulated in meal form and fed in three phases for both experiments. Pigs were weighed and feed disappearance was determined every 14 days.

The addition of fat to diets increased ADG in the first two periods of Experiment 1, and tended to increase growth for the overall study (Table 2). Adding fat also reduced feed intake and improved feed efficiency during each period.

Adding fat to diets increased ADG in lightweight pigs, but not in the heavyweight pigs in the first study. This interaction was unexpected, so a second study was conducted.

Table 3. Effects of Added Fat and Initial Sort on Growth and Variation of Growth in Grow-Finish Pigs (Exp. 2)a
Main Effects
Fat Addition Weight
Item Fat No Fat Heavy Light Mixed
Average daily gain, lb.
Day 0 to 49 1.87 1.79 1.85 1.79 1.83
Day 49 to 81 2.09 2.05 2.09 2.07 2.07
Day 81 to 95 2.18 2.12 2.27 2.03 2.12
Overall 1.98 1.92 1.96 1.92 1.94
Average daily feed intake, lb.
Day 0 to 49 4.19 4.45 4.52 4.10 4.32
Day 49 to 81 5.20 5.67 5.60 5.25 5.45
Day 81 to 95 6.00 6.53 6.57 5.95 6.26
Overall 5.05 5.47 5.73 4.81 5.22
Day 0 to 49 2.22 2.50 2.44 2.27 2.33
Day 49 to 81 2.44 2.78 2.70 2.50 2.56
Day 81 to 95 2.78 3.13 2.86 2.94 2.94
Overall 2.38 2.70 2.56 2.44 2.50
aA total of 1,176 gilts (28 pigs/pen and seven pens/treatment) with an initial average weight of 77.4 lb.
Table 4. Effects of Added Fat and Initial Sort on Weight Variation, Carcass Traits, and Economic Value in Grow-Finish Pigs (Exp. 2)a
Main Effects
Fat Addition Weight
Item Fat No Fat Heavy Light Mixed
Weight, lb.
Day 0 77.4 77.6 83.1 71.7 77.6
Day 49 168.7 164.7 174.1 159.2 166.9
Day 81 235.9 230.7 240.7 225.9 233.3
Day 95 264.5 258.9 269.3 254.2 261.7
Weight, CVc
Day 0 12.65 12.58 9.66 12.32 15.86
Day 49 10.86 11.06 8.74 11.12 13.02
Day 81 9.44 9.82 8.36 9.54 11.00
Day 95 8.60 8.93 7.35 9.22 9.71
Average daily gain CVc
Day 0 to 49 13.32 13.49 11.86 13.79 14.57
Day 49 to 81 12.57 15.32 14.91 13.31 13.62
Day 81 to 95 21.11 21.64 19.07 25.19 19.86
Overall 9.53 9.76 9.15 10.03 9.77
Economic Value
FC/lb. Gain, $ 0.163 0.159 0.168 0.159 0.163
Sort Discount, $ -3.08 -2.56 -3.35 -1.90 -3.22
MOFb, $ 93.30 92.59 96.28 90.13 92.42
aA total of 1,176 gilts (28 pigs/pen and seven pens/treatment) with an initial average weight of 77.4 lb.
bMargin Over Feed; calculated using corn $2.16/bu, SBM $186.19, Fat $13.34/cwt, Carcass Base Price $45.39
cCV = Coefficient of variation

In the second study, pigs fed diets with added fat had greater ADG through Day 49 of the study, and overall (Tables 3 and 4).

Adding fat also lowered average daily feed intake and improved feed efficiency during every period and for the overall study.

Similar to the first experiment, pigs sorted into heavy pens had greater ADG overall when compared to light or mixed pens. Lightweight pigs had a better overall feed efficiency compared with heavy or mixed pigs.

Researchers concluded that profitability in the lightest 50% of the pigs was increased by $1.46/pig in the first experiment, and $3.19/pig in the second experiment by feeding high-fat diets; average profit overall was $2.33/pig. Because this profit is only achieved on 50% of the pigs, it is worth $1.16/pig marketed, researchers noted.

Many nutritionists estimate that split-sex feeding within the same barn is worth $.50 to $.60/pig. The KSU results indicate that dividing the groups by initial weight, and feeding a higher energy diet to the lightest 50% of the pigs in order to increase growth rate, yields a greater return than dividing the group by sex. Large production systems could gain added benefits if pigs were fed by weight in addition to split-sex feeding benefits.

Researchers: Chad Hastad, Mike Tokach, Steve Dritz, DVM; Robert Goodband, Joel DeRouchey and Jim Nelssen, Kansas State University. Contact Tokach at (785) 532-2032 or e-mail

Impact of Nursery Diet Ingredients On Feed Flow

High concentrations of lactose and specialty protein sources in nursery pig diets can cause bridging in bins and feeders. Kansas State University researchers recently conducted two experiments to determine the effects of different lactose and specialty protein sources on the flow characteristics of a 70:30 corn-soybean meal-based nursery diet.

The first experiment focused on six lactose sources. Three sources were fine powdered whey permeates, and the other sources were coarse ground whey permeate, edible grade spray-dried whey, and a crystalline lactose source. Lactose sources were added at 0, 5, 10, 20 and 30% to the corn-soybean meal blend (Figure 1).

Researchers measured the maximum angle in which a pile of ingredient retained its slope, called the “angle of repose.” A large angle of repose represents a steeper slope and poorer flowability of the feed ingredient.

Increasing the inclusion of the lactose source showed good flowability; however, the coarse whey permeate had a much greater improvement in flowability.

The second experiment evaluated five specialty protein sources: spray-dried animal plasma in powdered and granulated form, spray-dried blood cells in powdered and granulated form, and select menhaden fish meal (Figure 2).

Specialty protein sources were added at 0, 2.5, 5, 7.5 and 10% to the 70:30 corn-soybean meal blend.

As powdered animal plasma and blood cells increased, the angle of repose increased, resulting in poorer flowability. Better flowability was achieved with the addition of granulated animal plasma and blood cells. Increasing fishmeal did not influence the flowability. The researchers concluded the greater flowability is observed with granulated specialty protein or coarsely ground lactose sources.

Lactose and specialty protein sources are often included in nursery pig diets to stimulate feed intake and improve growth performance. The researchers suggest adding granulated specialty protein sources to meal diets to improve feed flowability. Adding granular ingredients like Dairy Lac 80, Appetein, or granulated blood meal improve flowability.

Although the addition of granulated lactose and specialty protein sources to meal diets will increase feed cost slightly, they will improve feed flowability and can help decrease feed bridging in bins, feeders and other feed handling systems. Researchers are currently testing whether angle of repose can be used in feedmills to measure the relative flowability of meal diets to prevent problems in the field.

Researchers: Erin Carney, Crystal Groesbeck, Robert Goodband, Mike Tokach, Jim Nelssen and Steve Dritz, DVM. Contact Carney at (785) 532-1277 or e-mail

Measured Digestibility Values for DDGS Aid Diet Formulation

South Dakota State University (SDSU) researchers measured digestibility values for distiller's dried grains with solubles (DDGS) that demonstrate for the first time that DDGS has nearly the same energy content as corn. This discovery will reduce the cost of formulating diets with DDGS.

SDSU scientists took 10 samples of DDGS collected from ethanol plants in South Dakota and formulated 11 diets. One diet was corn-based, and the rest were formulated by mixing each of the 10 sources of DDGS and the corn diet in a 1:1 ratio.

Eleven growing pigs were placed on test at 64.5 lb. for 22 weeks in metabolism cages that permitted total, but separate, collections of urine and feces. Each pig was fed each diet for two weeks.

All samples of urine and feces were analyzed for concentrations of energy, crude protein and phosphorus, and the Apparent Total Tract Digestibility (ATTD) for energy, protein and phosphorus were calculated. Levels of digestible energy (DE) and metabolizable energy (ME) in each source of DDGS were also calculated.

Results are presented in Table 1. The average ATTD values recorded for energy, crude protein and phosphorus in DDGS were 76.8%, 83% and 59.1%, respectively. The energy and protein digestibility values are similar to those found in corn.

However, the phosphorus digestibility in DDGS is much higher than that of corn, reducing the need for monocalcium phosphate in the diet by 5 lb./ton of feed if 20% DDGS is included in the diet. That represents a savings of about $0.5/ton of feed.

The DE and ME values may vary among sources, but the experiment showed that the values are close to those of corn. The values for DE and ME in this experiment are 21% and 27%, greater than the values currently listed by the National Research Council.

Because energy values are similar to those found in corn, it eliminates the need to add extra oil to diets containing DDGS to maintain the same energy level.

“When pork producers and feed companies formulate diets with DDGS, they now have measured values for DE, ME and phosphorus digestibility to use in the formulas,” says lead SDSU researcher Hans Stein. “By using the energy value of DDGS, other nutrients may be included at ratios that match the energy in the diet. Therefore, diets containing DDGS can be more accurately formulated.”

Because values for phosphorus digestibility are now available, diets can be formulated without under- or oversupplying phosphorus, thus reducing the level of phosphorus excretion into the environment without lowering animal performance.

Researchers: H.H. Stein, C. Pedersen and M.G. Boersma, South Dakota State University. Contact Stein by phone (605) 688-5435, fax (605) 688-6170 or e-mail

Table 1. Apparent Total Tract Digestibility (ATTD) of Energy, Protein and Phosphorus, and Concentrations of Digestible Energy and Metabolizable Energy in Corn and in 10 Sources of DDGS Fed to Growing Pigsa
Item Corn Distiller's dried grains w/solubles (DDGS)
Average Range
ATTD, energy, % 90.4 76.8 73.9 to 82.8
ATTD, protein, % 81.5 83.0 77.1 to 87.5
ATTD, phosphorus, % 19.3 59.1 50.1 to 68.3
Digestible Energy, kcal/kg. Digestible Matter 4,090 4,191 4,015 to 4,555
Metabolizable Energy, kcal/kg. Digestible Matter 3,989 3,871 3,678 to 4,255
aData are means of 11 observations/treatment.

DDGS Boosts Sow Nutrition; Phytase Cuts Phosphorus Loss

High-producing lactating sows can thrive using 15% distiller's dried grains with solubles (DDGS) to help meet their nutritional needs.

Equally important, adding phytase to these DDGS-supplemented sow lactation diets reduced phytate phosphorus excretion levels over sows fed conventional sow rations or a complete DDGS ration without phytase.

Two studies were completed using Yorkshire × Landrace sows nursing 11 or more pigs/litter, weaned at 18 days of age.

The first study compared sows fed 15% DDGS with sows fed 5% beet pulp (BP). The diets contained the same amount of fiber, lysine (1.2%), calcium (0.9%) and phosphorus (0.84%).

Treatment did not influence lactation performance. Sows weaned 10.9 and 10.8 pigs/litter with an average gain of 8.4 and 8.6 lb./pig for the BP- and DDGS-fed sows, respectively. Weight loss during lactation was 13.6 lb. (BP) and 17.9 lb. (DDGS). Fecal phosphorus excretion decreased linearly for DDGS-fed sows.

In the second study, a 15% DDGS sow lactation diet was compared with three other diet formulations. The trial included a control group (typical corn-soy diet), control group plus phytase, control group with 17% of phosphorus supplied by 15% DDGS and this same DDGS diet plus phytase.

At 110 days of gestation, sows were gradually introduced to their lactation diet. Two days postfarrowing, litters were crossfostered to 11 pigs/litter and sows and litters were weighed. Fecal grab samples were collected from 48 sows (12/treatment) on Day 7, 14 and 18 of lactation. Litter weight gain (101.2, 101.9, 92.6 and 92.8 lb.) and sow weight loss (17.8, 15.8, 15.4 and 13.9 lb.) were not affected by the respective dietary treatments.

The phosphorus concentration in the feces was similar between treatments on Day 7, 14 or 18, but was reduced in sows fed all treatments on Days 14 and 18.

Significantly, however, fecal phytate phosphorus (the form of phosphorus in corn and soybeans) was reduced in sows fed the DDGS-phytase diet at Day 14 and 18, vs. sows fed the three other diets.

Researchers: G.M. Hill, D.L. Kirkpatrick, J.E. Link, M.L. Gibson, K. Karges and M.J. Rincker, Michigan State University; and Dakota Gold Research Assn. Contact Hill by phone (517) 355-9676, fax (517) 432-0190 or e-mail

Feeding Trials Support Added Fat Benefits, Discount Genetic Link

Two experiments conducted by the University of Nebraska confirmed the benefits of added fat to grow-finish performance and discounted any genetic link between sire line and dietary treatment.

In each experiment, rations consisted of corn-soybean meal-based diets with no added fat and corn-soy diets with added fat. The level of added fat ranged from 3.75% for the 40- to 70-lb. weight period to 1.5% for pigs over 220 lb.

Pigs fed in the experiments were progeny of Danbred females bred to four different Danbred sire lines.

Feeding trials showed there were no interactions between sire line and dietary treatment in either experiment. And there was no effect of dietary treatment on daily gain.

Feed conversion improved 6.8% in the first experiment with the added fat vs. the control diet, but only 3.7% improvement for the added fat group in the second experiment.

The lack of daily gain response, when combined with a lack of genetic interaction, suggests that for at least these genetic lines, daily gain is not a consideration as to the use of fat in grow-finish diets.

Researchers: Mike Brumm, University of Nebraska; Larry Himmelberg, formerly of Danbred; and Tom Rathke and John Sonderman of Danbred North America. Contact Brumm by phone (402) 584-3816, fax (402) 584-3859 or e-mail

2005 Swine Research Review - Herd Health/Management

Herd Health/Management

The Impact of PRRS On Cost of Production

Four pork industry analysts used a combination of techniques and data to project the current annual cost of porcine reproductive and respiratory syndrome (PRRS) to the U.S. swine industry.

The USDA-National Animal Health Monitoring System (NAHMS) conducts a survey every five years to provide a valid demographic and descriptive survey of the U.S. swine industry. The most recent survey of pork production operations was in 2000. The next NAHMS survey of hog operations will be in July 2006, and the results will be published in March 2007.

PRRS was a specific focus of the 2000 NAHMS survey. It showed that PRRS was the second-most often reported health problem in breeding herds (21.4%).

Using a case study approach, the NAHMS group surveyed information on farms across the United States to estimate the prevalence of PRRS-affected farms by production phase.

Also, a Delphi-type survey of industry personnel (primarily swine veterinarians) familiar with PRRS was conducted to help with estimating the annual cost of the disease. A Delphi survey is a structured group interaction process that provides opinion collection and feedback, validated on a national scale for detailed information on PRRS.

In the breeding-farrowing phase, the economic impact of PRRS was calculated to be $74.16/litter on affected farms. Of this amount, $45 was derived from a reduction in the number of pigs weaned/litter, and $29.16 was due to reduced farrowing rate.

The cost of PRRS in the nursery was pegged at $6.01/head on affected farms. This amount was comprised of $3.58 for increased pig mortality, $1.17 for reduced feed conversion and $1.26 for reduced average daily gain.

In grow-finish, the cost of PRRS was projected at $7.67/head on affected farms. Of this total, $3.23 was due to increased mortality, $3 for reduced feed conversion and $1.44 was attributed to reduced average daily gain.

Overall, based on NAHMS information and the size of the U.S. pig industry, the annual cost of PRRS is projected to be $66.75 million in breeding-farrowing, $201.34 million in the nursery, and $292.23 million in finishing. Combined, the total is $560.32 million.

A much higher cost of PRRS was arrived at when the Delphi survey data was summarized. The annual cost of PRRS was estimated at $111.12 million in breeding, $244.53 million in the nursery and $406.15 million in finishing for a total impact of $761.80 million.

The study was completed using pork checkoff funds.

Researchers: Colin Johnson and John Mabry, Iowa Pork Industry Center; James Kliebenstein of Iowa State University; and Eric Neumann, DVM, formerly of the National Pork Board. Contact Johnson by phone (515) 294-2340 or e-mail

Bacterial Product Cuts Antibiotic Use, E. coli Problems

Beneficial bacteria, cultured in a research laboratory, hold promise as an alternative to antibiotics in providing a cost-effective treatment for postweaning E. coli problems.

The patented bacteria that is harvested, often referred to as commensal bacteria, is produced naturally in the pig.

The new treatment approach involves colonizing a baby pig's intestinal tract with a mixture of beneficial bacteria, which are designated as RPCF (recombined porcine continuous-flow).

The field trials consisted of six geographically separated farms (five nursery sites in Kansas, Minnesota and Missouri, and one wean-to-finish operation in Iowa), with a history of high mortality from K88 and F18 strains of E. coli.

On those farms, piglets were orally administered a 2 ml. dose of the cultured bacteria within 24 hours of birth, and monitored through the nursery phase.

A total of 21,467 piglets were treated with RPCF. A similar number of piglets served as untreated controls.

On five of six farms, the beneficial bacteria reduced the impact of E. coli at a fraction of the cost of antibiotics. Mortality in RPCF-treated pigs decreased by an average of 2.6% over untreated control pigs (Table 1). Differences in mortality were not observed for the different treatment groups on one Minnesota farm.

When projected to an annual basis, the economic benefits from decreased medication costs and mortality averaged $24,663/farm.

Lead researcher Roger Harvey, DVM, with the Agriculture Department's Agricultural Research Service in College Station, TX, concludes that although RPCF is not a “silver bullet,” research results suggest it may serve as a valuable intervention method, when used with other management practices, to lessen the effects of E. coli. RPCF also offers a viable alternative to antibiotics in pig production, thus curbing concerns about antibiotic resistance.

The treatment is not yet approved for commercial use. Harvey says it may take two years or more before it is licensed and commercialized. He projects the product will cost in the range of $0.50 to $1/dose.

Researchers: Roger Harvey, R.C. Anderson, K.J. Genovese, T.R. Calloway and D.J. Nisbet, Southern Plains Agricultural Research Center. Phone Harvey at (979) 260-9259, fax (979) 260-9332 or e-mail

Table 1. Effects of a Defined Culture of Commensal Bacteria of Porcine Gastrointestinal Tract Origin* on Mortality and Medication Costs Due to Escherichia coli (E. coli)
Location (No.) Mortality plus cull, % Medicine cost/pig, $
Farm A (Missouri)
Control (3,242) 9.06 0.70
RCPF (10,402) 2.80 0
Difference 6.16 0.70
Farm B (Missouri)
Control (6,318) 3.33 0.11
RCPF (4,900) 2.54 0
Difference 0.79 0.11
Farm C (Missouri)
Control (3,068) 3.30 0.28
RCPF (3,127) 2.45 0
Difference 0.85 0.28
Farm D (Iowa)
Control (1,331) 9.00 0.40
RCPF (1,288) 4.20 0
Difference 4.80 0.40
Farm E (Kansas)
Control (350) 1.50 0.10
RCPF (250) 0.90 0
Difference 0.60 0.10
Farm F (Minnesota)
Control (1,500) 0.40 4.0
RCPF (1,500) 4.0 0
Difference 0 0.40
*RCPF refers to recombined porcine continuous-flow.

Crowding Reduces Performance, Floor Type Doesn't

Crowding is known to affect the performance of grow-finish pigs. But research at the Prairie Swine Centre (PSC) in Saskatoon, Saskatchewan, discredits the belief that pigs need more floor space if housed on partially slotted floors.

PSC scientists placed four blocks of grower pigs averaging 81 lb. on full or partially slotted flooring at three levels of space allowance: 4.1 sq. ft./pig, 5.81 sq. ft./pig and 8.40 sq. ft./pig. The lowest space allowance was discontinued after the grower phase.

Average daily feed intake was not affected by floor type or floor space allowance in grower or finisher phases.

Average daily gain tended to be less on partially than on fully slotted floors during the grower phase (Figure 1), but in general did not differ during the finishing phase of production.

As expected, pigs tended to grow slower on the lowest floor space allowance than the two other space allowances.

Average daily gain tended to be reduced by crowding during the finishing phase. PSC researchers estimate that this represents a lost opportunity of about $1/hog marketed at $0.65/lb.

Researchers: T. Done, S.M. Hayne and H.W. Gonyou, Prairie Swine Centre, Saskatoon, Saskatchewan, Canada. Phone PSC at (306) 373-9922, fax (306) 955-2510 or e-mail

Developing Better Oral Vaccines For K88 E. coli

Infection with enterotoxigenic E. coli (K88, now known as F4) causes postweaning colibacillosis (PWC) in 4- to 6-week-old pigs. Current vaccine strategies provide maternal immunization, conferring protection to piglets. But this protection wanes at around 5-6 weeks of age, leaving piglets susceptible to infection.

Antibiotics are the main line of defense against E. coli, but an effective vaccine may provide better protection while decreasing the use of antibiotics.

Researchers at the Vaccine and Infectious Disease Organization (VIDO) in Saskatoon, Saskatchewan, are trying to develop effective oral vaccines against PWC by inducing mucosal immunity in the small intestine.

Oral vaccination is being tested using a recently developed gut-loop model, which is based on the surgical creation of independent intestinal segments (loops) in piglets. All loops remain within the animal for four weeks. Various vaccine formulations are administered into the loops, and local immune responses to vaccination are assessed for four weeks.

Having access to multiple loops (6-8 loops/animal) allows VIDO researchers to assess multiple doses and vaccine formulations within the same animal, eliminating environmental fluctuations.

Using the model, it was found that the vaccine induced the strongest immune response when the animal had the highest level of K88 receptors present in its small intestine.

This has implications for the development of future vaccines, as it demonstrates that the K88 status of the animals is more important to vaccine effectiveness than the dose given or the adjuvant used.

Researcher: Volker Gerdts, Vaccine and Infectious Disease Organization, Saskatoon, Saskatchewan, Canada. Contact Gerdts by phone (306) 966-1513, fax (306) 966-7478 or e-mail