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Articles from 2003 In February

Defining Moments

There are certain events and decisions in everyone's life that have a major impact. We often call these “defining moments.” Some come suddenly, others more slowly.

Industries have defining moments, too. Looking at the pork industry the latter half of the 20th century, the formation of the National Swine Growers Council in 1954 qualifies as a defining moment. This council focused on developing meat-type hogs and initiating pork-specific promotional programs.

A decade later, amendments to the Packers & Stockyards Act paved the way for a voluntary checkoff program. In 1965, industry stakeholders met in Moline, IL, and developed the “Blueprint for Pork,” a master strategy to organize the nation's pork producers — another pivotal event.

A national voluntary checkoff program, dubbed “Nickels for Profit,” was launched in 1968, providing a vehicle for producers to contribute 5¢/head to a national fund.

Legislative Checkoff Drafted

Twenty years after the renowned “Moline meeting,” industry stakeholders refocused on helping draft a legislative initiative prescribing a national, mandatory checkoff program under which all producers of hogs and pigs and importers of hogs and pork products would be required to contribute to an industry self-help fund. The Pork Promotion, Research & Education Act was incorporated in the 1985 Farm Bill and enacted in 1986 at an initial rate of 25¢/$100 of market receipt value. The Pork Act dictates that the rate cannot exceed 50¢/$100 value.

Fifteen years later, a handful of pork producers challenged the mandatory checkoff enacted by Congress, on the grounds that it violated their First Amendment rights. Their argument — they oppose having to contribute to programs and promotional messages they do not endorse.

The USDA conducted a referendum on the legislative checkoff in the fall of 2000. The tabulated results were challenged, setting in motion a series of legal challenges and appeals from both sides of the issue.

The fate of the checkoff now resides in the hands of the judicial system, possibly even, the highest court in the land — the Supreme Court.

If lower court rulings and appeals push the case that far, I'm told the Department of Justice and the USDA will encourage Supreme Court justices to hear the appeal and provide a ruling that could affect other commodity checkoff programs, too.

Meanwhile, a great deal of scrutiny and soul-searching has occurred at all levels of the pork industry's governance. At the 2002 Pork Industry Forum, the official business meeting of the National Pork Board, delegates voted to reduce the mandatory rate from 45¢/$100 market value to 40¢.

Discussions about the mandatory checkoff rate continued, however. Some argue that the industry and the challenges it faces have changed so dramatically since the inception of the mandatory checkoff that the funds would be better spent on matters of public policy and regulatory issues. By law, however, funds collected under the Pork Act cannot be used for lobbying or advocacy initiatives.

The compromise, proposed through resolutions at some state meetings, is to lower the mandatory checkoff rate further and encourage producers to reallocate those funds to a voluntary contribution program such as the Producer Consent program managed by the National Pork Producers Council (NPPC), the industry's advocacy organization.

Minnesota delegates passed a resolution calling for the mandatory rate to be reduced to 35¢. However, producers in three other states supported resolutions calling for the rate to be dropped to “0” — thereby eliminating the mandatory program and paving the way for voluntary contributions to unrestricted funds, such as the Producer Consent program.

File Your Opinions

Regardless of the decisions that could come from the judicial system, it is apparent that priorities differ amongst producers and states. When state delegates meet in Dallas on March 6-8, it is imperative that they clearly understand your wishes. If you don't know your state delegates or how to contact them, call your state pork producer association office or the National Pork Board (800-456-7675). If you can't find the information you need, call me, and I'll help you find it.

The activities of the past 24 months have positioned the U.S. pork industry at the cusp of another defining moment. It is essential that all pork producers consider the impact a change in the checkoff rate will have on industry research, education and promotion programs. Take stock. Think through the best- and worst-case scenarios these actions will have.

The decisions made at this year's Pork Forum could shape the U.S. pork industry for the next decade or two. This is a defining moment. Do not squander it.

Ileitis: New Approach to Old Foe

Ileitis caused by Lawsonia intracellularis has been a frustrating problem for pork producers for many years.

Although several antimicrobials have been shown to control the clinical disease, outbreaks among growing pigs and replacement gilts have been, in some instances, devastating.

The acute form of ileitis is sometimes dramatic, giving rise to blood-tinged diarrhea and occasionally sudden death. This form of the disease is especially maddening when the affected animals are bred gilts about ready to farrow.

A more insidious manifestation of the disease is the subclinical form that robs profits by lowering performance. Many times, this form of the disease goes unnoticed unless individual pigs become chronically infected. These pigs never achieve market weight, and if they do not die, are often considered of no value at close out.

A novel approach to controlling ileitis has been the introduction of an avirulent (nonpathogenic) live vaccine. It has had a huge impact on both the incidence and severity of ileitis outbreaks, and has reduced the reliance on antimicrobials in replacement gilts and grow-finish.

The following case studies demonstrate how antimicrobials and the avirulent vaccine can reduce disease and improve performance.

As with any new technology, there is a learning curve with this vaccine. The second case study outlines the attention to detail needed for proper immunization.

Case Study No. 1

A farm purchasing replacement gilts was concerned about preventing ileitis in new animal introductions. Females had a history of late grow-finish death loss after entering into the replacement sow farm. Medication would reduce, but not completely eliminate, clinical signs of ileitis. To prevent losses associated with ileitis, replacement females were vaccinated prior to leaving the grow-finish farm.

The vaccination protocol at the source farm was performed exclusive of any feed medications shown to be effective against ileitis. The vaccine label requires no antibiotics for three days prior and three days after vaccination.The producer gave developing gilts a full dose of vaccine after hearing about reduced efficacy and clinical signs from neighbors who had tried using a partial dose of the vaccine.

A pulse dose of therapeutic levels of chlortetracycline (10 mg./lb. body weight) was implemented to protect animals during the process of developing active immunity, about four weeks after vaccination.

Gilt performance in the grow-out barn reflected a 35% reduction in mortality, 8% improvement in growth rate and reduced medication use. Gilts were able to enter sow farms without any losses. No feed medications against ileitis were needed.

Case Study No. 2

A grow-finish system was experiencing finisher losses due to ileitis. Pigs throughout finishing would develop runny stools and grow poorly. Heavyweight animals just before and after first marketings from the barns would develop black stools, or simply be found dead with bloody feces. Feed medication with tylosin at 100 and 40 g./ton reduced clinical signs, but did not prevent outbreaks.

The finishing manager decided to try vaccination with the water-soluble ileitis vaccine from Boehringer Ingelheim (Enterisol Ileitis). Grow-finish pigs in 11 barns were vaccinated, and 10 comparable barns were left as controls.

All feed medications were taken out of the last nursery diet to allow vaccination without inactivating the live vaccine. A Ready Pack container with dye and chlorine neutralizer was used to prevent inactivation of the vaccine by any chlorine in the water. The producer charged the lines to all the pens that were getting vaccinated.

Feed medications were removed during the last 10 weeks of production in vaccinated barns to fully check vaccine potential. A growth promotant such as 10 g. of tylosin or BMD was used in the first 10 weeks. Control barns had 100 g. of tylosin in early finishing for three weeks, and 40 g. of tylosin in the last two diets.

No breaks of ileitis occurred in the vaccinated pigs, while several barns of control pigs broke while on medication. Mortality was prevented using tiamulin (Denagard Liquid Concentrate) in the drinking water.

Growth rate was also 5% better in the vaccinated groups. Reducing the level of medications paid for over half the vaccine cost.


The use of this new technology requires careful planning on the part of the producer and their veterinarian. Timing of the vaccination is critical since it requires at least three weeks for the pigs to acquire immunity. Using vaccine with approved medications can allow producers to prevent and control ileitis, while at the same time reducing their reliance on continuous feeding of antibiotics.

COOL Comments Extended

The U.S. Department of Agriculture has extended the comment period for country-of-origin labeling (COOL) to Feb. 21, 2003.

Trade groups requested the extension to provide more time to submit comments.

COOL calls for a two-year voluntary program followed by a mandatory labeling program for meat and fresh fruits and vegetables.

Comments should be sent to Country of Origin Labeling Program, Agricultural Marketing Service, USDA STOP 0249, 1400 Independence Ave. SW, Washington, DC 20250-0249; faxed to (202) 720-3499 or sent by e-mail to

Is 28-day Weaning a Bad Thing?

It may seem strange to many American producers that the European Union (EU) is proposing delaying the legal piglet weaning age from the current 21 days of age to 28 days. Why is this?

After the trauma of foot-and-mouth disease (FMD), various European pig production methods have experienced intense scrutiny from our European media, the public and politicians.

This concern, now being applied to weaning age, seems to be based on extremely thin evidence that there is an increased level of stress and stereotypic behavior among pigs weaned at 3 weeks of age compared to 4 or 5 weeks of age.

The subject is under discussion, but it looks rather likely that the change to 28-day weaning will be made. However, some are suggesting that producers with up-to-date nurseries may be allowed to continue with the present 21-day edict — although how this can be “policed” is dubious, surely.

The British, ever the pragmatists, and the Swedes, leaders in acceding to welfare “improvements,” have already done some trial work on what this rise in weaning age may mean.

Results Favorable

Plenty of performance evidence shows that another kilogram of weight per pig (2.2 lb.) at 24-day weaning reduces age to slaughter by 15 days (9% in our case).

The feed firm SCA tested delaying weaning age from 21 to 28 days in carefully controlled trials (Varley 2002). This included costings on both regimes as, of course, pushing back weaning age by a week necessitates more farrowing crates per pig produced, higher creep feed costs and a reduced farrowing index.

The first finding was that the target weaning age should be 30 days in order to abide by the 28-day legal minimum in any one weaning week. Of course, weaning weight increased due to the 7-9 day delay — from 15 lb. to 19.1 lb.

Impact Productivity, Profitability

As borne out by earlier work where 24-day-old weaners were 2.2 lb. heavier than their contemporaries, overall performance in the SCA trial favored the litters weaned later (Table 1).

“Ah,” you say, “But what about reduced turnover which reduces income/sow/year? And what about increased breeding unit costs? Does the improved productivity to slaughter/ sow outweigh the penalty costs?”

The SCA trials shown in Table 2 suggest that later weaning provides piglets with a better immune status, especially cell-mediated immunity. They also will have a better thermoregulatory system should the farrowing or nursery environment be sub-standard.

In addition, that extra 3½ lb. at weaning favorably affects gut development, which is critical to post-weaning nutrition. It also makes feeding those pigs so much easier.

A Few Precautions

  • Good creep feeds and feeding practices are essential; otherwise, the more heavily milked sow will be shattered.

  • Very good sow nutrition, environment and management are equally essential to defend the sow against the depredations of 25% heavier piglets in their final, ferocious week of suckling.

    In addition to the possible economic benefits, why are Europeans even considering later weaning?

  • By 2006 we will not be able to use any antibiotic growth promoters.

  • Copper sulfate is to be banned in the EU at over 30 ppm from its present 175 ppm level due to soil residues. And, zinc oxide at 3,000 ppm in weaner feeds will be banned. Both are useful and cheap gut conditioners.

  • Milk and milk byproducts are becoming more and more expensive.

  • A week's longer gut enzyme system changeover, to accommodate more normal feed ingredients, makes postweaning nutrition easier and cheaper.

Perhaps the European move to later weaning is not so daft after all.

Table 1. Performance of 23-day vs. 30-day Weaning

23 days 30 days
Litter size (born alive) 11.3 11.6
Pigs produced/sow year 26.8 26.5
Days to slaughter 172.95 157.88 (8.7% better)
Source: SCA (2002)

Table 2. Economics of 23-day vs. 30-day Weaning

23 days 30 days
Gross margin/sow (indexed) 100 116 16% better
Return on breeding farm capital (indexed) 100 110 10% better
Feed costs ($/finished pig) 41.44 36.18 10.6% lower (ie better)
Fixed costs ($/finished pig) 81.33 74.24 8.7% lower (ie better)
Total costs ($/finished pig) 121.79 110.40 9.35% lower (ie better)
Source: SCA (2002)

Reproductive Biology 101

Sifiting through the various causes of reproductive failure generally requires a better understanding of the biology of reproduction.

Once the basics of reproductive biology are mastered, producers and managers can apply “critical analysis” principles to get to the root of low farrowing rates and small litters.

North Carolina State University swine reproductive specialist Billy Flowers is often called in to help solve reproductive shortfalls. Commonly, he starts by identifying where in the reproductive process things can go wrong.

On the boar side, Flowers focuses on spermatogenesis. That includes what happens in the testicle and sperm storage in the epididymis.

On the female side, he explores the fertilization process, as well as embryonic and fetal survival and development.

Boar Biology

Flowers turns to a schematic diagram of spermatogenesis for a review of the three basic steps of a boar's reproductive physiology (Figure 1).

Spermatogenesis works in a continuum; every 2-3 days a new group of sperm cells leaves the “resting pool” (testicles), moves on to the “developing pool”(testicles and epididymis), where the multiplication and maturation process advances over a 5- to 7-week period. In this ongoing process, matured sperm cells advance to the “storage pool” (epididymis proper) every 2-3 days. Semen for natural mating or collection for artificial insemination comes from there.

“Male reproductive physiology is a replenishing process,” explains Flowers. “Every time you have one cell leave the resting pool, one cell stays behind, and the others (advancing cells) actually start to produce more sperm cells. It replenishes itself so, really, you don't have to worry about the boars running out of the potential for producing sperm cells.”

Occasionally, a stress disrupts this process, which Flowers refers to as an “insult.”

“An insult may be something that you don't intend to do but it actually affects the boar's performance,” he explains.

For example, a boar is exposed to a very transient insult that occurs for just a few hours or a day. If severe enough, it will alter sperm production. But, because of the time it takes for sperm to mature, the impact of the insult will not be seen for a couple of weeks. Then, sperm quality gradually declines.

In the continuum, sperm quality gradually stabilizes, and then returns to normal, assuming the insult has been rectified. Normally, these insults have their greatest impact on developing sperm rather than the sperm in the resting or storage pools.

“In many cases, we have to rely on retrospective analysis to determine what happened,” Flowers says.

Prospective indicators, often seen as degrees of damage to the tails of the sperm cells, are shown in Figure 2. Curved or U-shaped tails often reflect a moderate insult has occurred; cooled or frozen semen often exhibit this tail position. Severe insults result in more sharply defined changes in the tail morphology, such as the tail folding back on itself.

Chronic insults, those less severe stressors that may occur over a long period of time, should also be checked. A good example is the gradual decline in the production of normal sperm cells as temperatures increase and stabilize. “With chronic insults, the boar copes with them for a certain period of time, then basically can't cope anymore,” he explains.

Female Biology

Equally important to the reproductive troubleshooting process is gaining a better understanding of female reproductive physiology, including the basics of maintaining pregnancy and the post-farrowing recovery period.

Flowers uses the most important reproductive event — breeding — as a reference point, then works backwards and forwards from there. A schematic diagram outlines specific reproductive events for his review (Figure 3).

Assuming an initial successful conception and farrowing, Flowers focuses on what must happen before the sow can be successfully bred again.

“Some things have to happen before she can resume a normal reproductive functioning,” he says. “Once the piglets are weaned, you remove the negative inhibition of lactation on the reproductive hormones.” What follows is a very rapid period of follicular growth, culminating in estrus, and then, hopefully, fertilization.

The next signal comes Day 12 to 14 after fertilization when estrogen signals the presence of embryos in the uterus. Another estrogen signal is sent between Days 17 and 28 days after breeding. The exact timing remains a subject of debate. A 12-week fetal development period follows.

Stumbling Blocks

“Reproductive performance is erratic and unpredictable in sows with short lactation lengths,” Flowers says. “Most sows probably cannot respond normally until Day 12 to 14, but there is significant variation amongst sows.

“There are two components of her reproductive system that need to recover — the brain (hypothalamus) and the uterus. The ovary is pretty much ready to go at farrowing, but the brain and the uterus actually lag behind.

“Here's what happens: the area called the hypothalamus — responsible for coordinating most all the things that the sow senses and then translates to an endocrine signal — loses its ability to respond normally to these (endocrine) signals until about Day 12 (post farrowing),” he explains.

Attempts to rebreed sows before the brain has fully recovered often result in the formation of cystic follicles. Follicles continue to grow because the sow can't elicit the normal luteinizing hormone (LH) surge needed for ovulation.

The uterus also needs about 14 days to recover after farrowing. “This is actually the physical replenishment of the uterine endometrium (lining), and the regeneration of some of the things that will actually support the next pregnancy,” he adds.

Beyond Fertilization

“In pigs, fertilization is a very efficient process,” Flowers says. “If everything is handled properly, we see fertilization rates at 90% or more.”

For a pregnancy to be maintained, signals from the embryos are essential. “If the sow does not receive the signal at Day 12 (post breeding), that means the embryos are not producing enough estrogen or there are no embryos there. Then, the sow will actually return to estrus in 20-21 days, as if she was never bred,” he says.

“Based on work done by Phil Dzuik (University of Illinois) back in the mid-'80s, we believe we need at least 4-6 embryos at Day 12, and again at Day 28, for the sows to receive the (estrogen) signals (needed to maintain pregnancy). If a sow doesn't get this second burst of estrogen, she will usually come back into heat somewhere between Day 28 and Day 40,” he adds.

Still, if everything is done perfectly, it is fairly common to lose between 25% and 40% of the embryos between fertilization and implantation. “This part of reproduction is a highly inefficient process,” Flowers says.


Given that brief reproductive biology lesson, Flowers sorts through scenarios producers can use to pinpoint reproductive problems. For example:

High embryonic mortality, low ovulation rates — check lactation length, lactation management (feed, etc.), plus anything that happens to the females the first two weeks after breeding.

Fertilization shortfalls — check breeding management, breeding techniques and semen quality; consider additive effects of insults to boars.

“When I visit with boar studs that are having problems, we make a list of things that possibly could influence sperm output, then we break them down into acute insults and chronic insults,” Flowers explains.

Acute insults include:

  • Transient temperatures above 85∞ F. (consider humidity);

  • Transient health problems (scours);

  • Vaccinations;

  • Changes in housing (moving boars around within the stud);

  • New collection techniques (change technicians);

  • Changes in collection frequency.

Chronic insults include:

  • Nutritional changes (type or formulation of diet);

  • Changes in types of housing (inability to adapt to new environment over a long period of time);

  • Long-term exposure to temperatures in upper end of thermoneutral zone.

Recognizing that not all of these insults are a problem in every operation, they are recorded during winter and summer months to build a frequency distribution. The frequency distribution, by stud, reinforces that multiple causes can have an impact on sperm output and quality.

All Boars Are Not Equal

Heterospermic insemination (blending of ejaculates from multiple boars) is a common attempt to overcome the possibility that a single boar's fertility might be low. Flowers has tested this philosophy in the laboratory through competitive insemination tests using equal numbers of sperm cells (1 billion each) from three boars to breed sows and genetically fingerprint the offspring.

Table 1. Results of Competitive Fertilization
Stud No of piglets Proportion sired by Boar 1 Proportion sired by Boar 2 Proportion sired by Boar 3
A 640 75%* 20% 5%
B 700 66%* 25% 9%
C 750 57%* 25% 18%
*different from Boar 2 and Boar 3 (p<.05)

“We never see a third, a third, a third,” he says. “These boars are of equal morphology, equal sperm production, equal motility, but we never, ever see a distribution of 33% across the boards. There's always one boar that sires most of the pigs in a given litter (see Table 1).

Critical Analysis of Reproductive Shortfalls

North Carolina swine reproductive specialist Billy Flowers uses the “biology of reproduction schematic” (Figure 3, page 13) when diagnosing reproductive problems in a sow herd. His “critical analysis” focuses on three measures — farrowing rate, return-to-estrus interval and litter size — information that is readily available in most recordkeeping programs.

Flowers reinforces that reproductive performance is situation dependent, influenced by genetics, environment, nutrition, etc. He suggests comparing performance among farms with similar genetics, management and production environment.

For his case study discussion (below and Table 1), he uses the reference points drawn from actual farm records he has worked with (Table 2).

Table 1. Critical Analysis of Reproductive Problems — Five Case Studies
Case Farrowing Rate Return Interval Litter Size
1 Bad < 22 days Bad
2 Bad > 28 days Bad
3 Good Bad
4 Bad < 22 days Good
5 Bad > 28 days Good

Case Study No. 1

Poor farrowing rate, poor litter size with normal return to estrus.

Checking the reproductive biology schematic, Flowers suspects the problems are occurring between Day 0 (rebreeding) and Day 12, because it appears the sows are not receiving the signals to continue pregnancy. “That's why you have a low farrowing rate, low litter size and return-to-estrus intervals less than 21 days,” he says.

From a reproductive biology standpoint, complete fertilization failure could be caused by breeding problems or poor semen quality, or short lactations and their effect on follicular development. High embryonic death losses before Day 12 and low ovulation rates should be considered.

Flowers assumes five embryos are needed to maintain pregnancy at Day 12, fertilization rates at 90% or above, and embryonic mortality rates at 40% — the upper end of normal (25-40% is normal).

Focusing on low ovulation rates, Flowers works backwards from an ovulation of 14 eggs (calculation: 5 embryos divided by .90, divided by .40 = 14 embryos). A herd averaging less than 14 ovulations/female likely will not be successful in maintaining a high percentage of pregnancies because a high percentage of hormone signals will be missed at 12 and 28 days, he says.

Case Study No. 2

Poor farrowing rate and litter size, return-to-estrus interval is greater than 28 days and irregular.

Flowers suspects short lactations could be affecting follicular development, thereby impacting farrowing rate and litter size.

It is unlikely that the irregular returns to estrus are being caused by fertilization problems or embryonic deaths in the first two weeks, because there are obviously enough embryos to send the first signal (Day 12). Therefore, focus on the causes of embryonic loss between Days 12 and 28.

Table 2. Reference Points from Farm Records in Southeast States
Rating Farrowing Rate % Litter Size
Bad < 80 < 10
Can Improve 81-85 10-11
Good >86 >11

Case Study No. 3

Good farrowing rates (therefore no concerns about return-to-estrus intervals), but average litter size is lower than expected.

Low ovulation rate could be a problem, but more likely something is happening during fetal development (between Days 28 and 114) to reduce litter size. Flowers reasons: “Obviously there are enough embryos to push sows past Days 12 and 28, the first and second signals to maintain pregnancy. Farrowing rate is good because the females are staying pregnant, but we're actually loosing live pigs.

“In this type of analysis, it's important to look at mummies and stillborns per litter. If it's a stillborn problem, it's happening toward the end of the fetal development period; with a mummy problem, it's probably happening after Day 60 or 70,” he says.

Case Study No. 4 and No. 5

Both herds have poor farrowing rate, good litter size, but No. 4 has returns to estrus under 22 days, while No. 5 has returns to estrus after 28 days.

Situations where one measure is good and one is bad can benefit from subset analyses. The more obvious subsets to examine are seasonal effects, and the percentage of first- and second-parity sows versus older sows.

“Because we have situations where litter size is really good, but farrowing rate is poor, we know that the sows that do farrow have normal litters. So, it's probably a subset (of females) that isn't farrowing.

“For most of the herds that have these scenarios, breeding regimens should be checked first. There could be a subset of sows which aren't receiving semen close enough to ovulation to achieve good fertilization. A simple adjustment in the timing of matings corrects the problem,” he notes.

In No. 4, consider that some animals have high embryonic mortality during the first two weeks — high enough that the pregnancy doesn't continue and they return to estrus within 21 days.

Case Study No. 5 is similar to No. 4 in that the animals that stay pregnant have normal size litters. “Something is happening to a subset of animals at around 28 days of fetal development. Consider the high embryonic mortality after Day 12 in the subset. This is typically what we would think of as animals being ‘pseudopregnant’ or ‘not in pig,’” he says.

Ultrasound can help diagnose this problem, however, you have to change your focus. “Normally you would have a normal pregnancy check with Real Time ultrasound (at) about Day 28, then you should come back around Day 60 or Day 70. This is important because it's after this time where most of the cartilage and bone in the piglet gets laid down, so there's a nice solid image,” he explains.

With a pseudopregnancy, the use of ultrasound at Day 70 will reveal large open areas — a sign that the uterus is full of fluid but no live embryos. When pigs are present, you should be able to see the outline of the skeleton and backbone at Day 70, he says.

“It's really important to train technicians, to look for solid objects instead of the dark circle. Or, you can use a higher frequency probe to get a better image. In ultrasound diagnosis, the low frequency probe gives you depth but you lose resolution. With high frequency probes (7.5 MHz), you get better resolution,” he explains.

product news

Organic Drying Product

France-based Olmix introduces Mistral, an organic drying product capable of absorbing practically its weight in liquid. This unique blend of seaweeds, alginates, diatomic earth, natural desiccants, (a drying agent), and essential oils is non-aggressive in action and does not burn. The company says that dunking piglets in Mistral immediately after birth reduces the risk of chilling, speeds drying of the umbilical cord, promotes suckling quicker and leads to faster growth. The product helps keep creep areas dry, reduces ammonia and odors, and is said to substantially reduce fighting.
(Circle Reply Card No. 101)

Durable Gilt Line

PIC USA announces the launch of the new Camborough 23 gilt, developed for producers seeking greater sow durability and longevity. The Camborough line is known for its mothering ability and prolificacy. Line 23 adds greater environmental and management flexibility. The gilt was bred in severe environmental conditions behind the Iron Curtain, often in outside areas, explains Bill Christianson, technical director of Genetic Development for PIC. The line produces terminal progeny with very competitive growth rates, feed conversions and lean content values, as well as excellent meat quality. In comparative trials in eight commercial farms in the U.S., Camborough 23 has met or exceeded Camborough 22 in the areas of gilt development, farrowing rates, feed cost, maternal characteristics, wean-to-estrus interval and durability. The gilts are currently available from five multiplier farms.
(Circle Reply Card No. 102)

Feed System Software

Agrotronix announces the release of its FCC2200 Feedpro Command Center software to control its Feedpro continuous-flow feed mixing system. This software package controls the operation of the feed-making process by controlling several types of metering units including continuous-flow by weight units, a loss-in-weight premix metering unit and the LX800 loss-in-weight premix mixer/metering unit. It also allows ration maintenance, provides ingredient inventory tracking, and permits complete feed records to be kept on a personal computer running Windows software.
(Circle Reply Card No. 103)

Bulk Bag Handling System

Easy Automation Inc. announces the release of its new and improved bulk bag handling system. This system features a ring adapter bottom to provide for easy attachment of common bulk bin-style auger boots and augers. The system also features an easily adjustable side shelf to adjust for bag size.
(Circle Reply Card No. 104)

Sow Stall

Dallas Mfg. introduces the 3D Pig Thing, a new design for handling sows from gestation through lactation. The concept is designed to address animal welfare concerns and provide maneuverable space for sows during confinement. The floor area is adjustable from 35 sq. ft. to 42 sq. ft., depending on the size of the sows. Two telescopic sliding interior gates provide a series of settings such as: opened wide during gestation, giving the sow full floor area; set in parallel during the sow's farrowing period; or open with protected corner creep area giving the sow 80% of the floor space during lactation.
(Circle Reply Card No. 105)

Manure Monitoring System

Phason introduces Omni-Manure, an automatic manure level monitoring system. The system constantly monitors manure levels without human intervention (lagoon, above-ground tank or under-slat storage pit). Omni-Manure determines the amount of manure accumulating over time by measuring the change in manure levels each day. Using this data, it estimates when the reservoir will be full. The system's charts and reports can provide early warning of leaks or high manure levels and proof of past manure levels. Information from Omni-Manure can also help producers plan and schedule manure spreading.
(Circle Reply Card No. 106)


Agri-Pro Enterprises announces the availability of the Lock ‘N’ Load syringe from Instrument Supplies. The syringe provides multiple dosing with two sizes, 20 ml. and 50 ml. The 20 ml. syringe delivers increments of 0.5 ml. to 5.0 ml. And the 50 ml. offers increments of 1.0 ml. to 5.0 ml. The syringe features metal and poly materials giving it a comfortable, lightweight and durable construction made to withstand heavy use with non-corrosive metal shafts. The Lock ‘N’ Load is easy to load and prime, features a reverse dosing dial selector and a cap for simple needle placement and removal.
(Circle Reply Card No. 107)

Phytase Can Replace Trace Mineral Premix

(Editor's note: Table 1 accompanying this research report, National Hog Farmer, Dec. 15, 2002, p. 18, was incorrect. Following is the complete report and correct table.)

Louisiana State University (LSU) Agricultural Center researchers recently discovered microbial phytase supplementation could replace added trace mineral premixes in nursery pig diets.

The primary reason phytase is added to swine diets is to help increase phosphorus availability and to reduce the amount of phosphorus excreted in feces.

The researchers say adding phytase to corn-soybean meal diets can increase the availability of calcium, phosphorus, energy and amino acids. In addition, phytase has been shown to increase the availability of some trace minerals, including copper, manganese, iron and zinc.

Researchers speculate the effect of phytase on trace minerals may mean trace minerals could be removed from diets when phytase is added.

The LSU research was conducted with 208 crossbred barrows and gilts, weaned at 21 days of age and fed four different diets.

Pigs were fed a conventional nursery diet with trace mineral premix (control diet), conventional nursery diet without trace mineral premix (- Mineral), control with microbial phytase (+ Phytase), or control with phytase but without trace mineral premix (-Minerals, + Phytase). See Table 1.

Average daily gain (ADG), average daily feed intake (ADFI) and gain:feed were measured at the end of Phase 1 (7 days), Phase 2 (14 days) and Phase 3 (13 days).

Researchers found pigs fed the conventional nursery diet without the trace mineral premix had decreased growth performance. However, pigs fed the same diet, but with supplementation of phytase, had growth performance equal to that of the pigs fed the control diet. Pigs fed the diet without the trace minerals returned to normal growth after they were fed the control diet for two weeks.

Table 1 shows the effects of the experimental diets on growth performance during the nursery phase.

Skin lesions developed on 26 of the 52 pigs fed the conventional nursery diet without the trace mineral premix. No lesions were found on any of the pigs fed the diets with the trace mineral premix or with the addition of phytase. The skin lesions were healed on all pigs after five weeks of being fed the control diet.

Researchers: Jason Shelton, L. Lee Southern, and Tom Bidner. Contact L. Lee Southern at (225) 578-3449, or e-mail

Table 1. Effect of Diets on Nursery Performancea
Item Control +Phytase -Minerals -Minerals +Phytase
Phase 1 (0 - 7 d)
ADG, g. 122 141 141 150
ADFI, g. 177 195 211 211
Gain:feed, g./kg.e 664 725 667 692
Phase 2 (8 - 21 d)
ADG, g.b 345 342 292 323
ADFI, g.b,c,d 538 539 462 546
Gain:feed, g./kg. 641 635 626 603
Phase 3 (22 - 34 d)
ADG, g.b,c,d 457 440 339 468
ADFI, g.b,c,d 812 819 609 819
Gain:feed, g./kg. 566 540 551 573
Overall (0 - 34 d)
ADG, g.b,c,d 342 338 277 350
ADFI, g.b,c,d 585 576 467 577
Gain:feed, g./kg. 584 587 590 607
aData are means of eight replicates of six pigs per replicate. Average initial and final bodyweight were 5.4 and 15.9 kg. for the gilts and 5.6 and 16.4 kg. for the barrows, respectively.
bMineral, P<0.05. e1kg.=2.2 lb.
cPhytase, P<0.02. ADG=average daily gain
dPhytase × mineral, P <0.02. ADFI=average daily feed intake

Mexican Standoff

The Mexican government's contention that the U.S. is dumping pork into their country is politically motivated and without merit, says Dave Roper, president of the National Pork Producers Council and a producer from Kimberly, ID.

“U.S. pork is not being dumped into Mexico,” he says. “This case is a blatant attempt by Mexican pork producers to make the renegotiation of the North American Free Trade Agreement (NAFTA) a major political issue. Mexican pork producers, who have benefited significantly since NAFTA was signed in 1994, are not satisfied with the current treaty and are currently disrupting Mexican commerce with protests and other measures aimed at further restrictions on American agriculture.”

Roper says Mexican hog operations are highly profitable and do not need protection from imported pork. “Mexican hog producers earn, on average, 17 times as much per kg. (2.2 lb.) of live hog as their counterparts in the U.S. These profits reflect high pork prices in Mexico in comparison to the prices in international markets, and the success of the Mexican pork industry in exporting pork.”

At the same time Mexico is trying to restrict pork imports, they are also trying to liberalize imports of feed grains into Mexico, he says.

Mexico is the second largest export market for U.S. pork with 210,000 tons of pork valued at $270 million shipped to Mexico in 2001.

Nebraska Index Cross Females Perform In Commercial Herds

The National Genetic maternal Line Evaluation Program (MLP), completed three years ago, showed distinct reproductive advantages for an F1 female that was a cross of the Nebraska Line (NI) line with Monsanto Choice Genetics maternal lines.

Since then, pigs of the NI line were released to several breeding organizations that have marketed NI line cross females to commercial producers. Data on the performance of these gilts are beginning to accumulate. This report summarizes that information with the objective of determining whether the NI cross gilts are living up to their reputation derived from the MLP results.

Monsanto Choice Genetics has since obtained exclusive rights to the line outside of Nebraska.

Development of NI Line

For those unfamiliar with the hyper-prolific NI line, it was developed in a selection experiment at the University of Nebraska, begun with a cross of Large White and Landrace in 1979. After two generations of random mating to mix the genes from the two breeds, index selection for increased ovulation rate and increased embryonic survival was initiated in 1981.

Index selection was practiced until 1991, a total of 11 generations. From 1991 to 1996, selection has focused on increased litter size at birth, emphasizing total number born. After 1996, emphasis was placed on number of live pigs born. Selection for increased growth rate and decreased backfat was included in the selection objective in the last three years.

Litter size in the NI line in the last generations has ranged from 13.5 to 14.2 pigs/litter — approximately four pigs/litter greater than a randomly selected control line. Until selection for growth and fat was initiated in 1999, no correlated changes in growth or carcass traits had occurred.

MLP Results Overview

In 1996, a cooperative effort between the University of Nebraska and Monsanto Choice Genetics provided gilts from a cross of NI lines with Monsanto lines to be evaluated in the checkoff-funded MLP test. Performance of these females was compared with that of females of five other industry lines through four parities, with approximately 625 gilts per line.

Table 1. Comparison of Performance of Nebraska Index (NI) Line Cross Females and Standard Cross Females in Herds in Which Both Types of Females Were Contemporary (6 Herds Represented)
NI line cross females Standard cross females
Trait Number Mean Number Mean Percentage advantage
Age at 1st service, days 679 219 1,865 221 0.9
Farrowing rate, % 2,019 84.9 3,439 79.3 7.1
Total born/litter 2,327 12.8 4,799 11.9 7.7
Pigs born live/litter 2,327 11.7 4,799 10.9 7.3
Weaning-to-service interval, days 530 6.9 1,805 7.2 4.2

Results of the MLP were widely published (see “Maternal Line Genetics” Blueprint, National Hog Farmer, April 15, 2000).

The bottom line, the total production of the NI cross gilts was 30 to 50% greater than other lines. Identified as MXP200 females in the test, but subsequently renamed GPK347 by Monsanto, the gilts bred at a younger age, and sows had greater conception rate, litter size, and shorter weaning-to-estrus intervals through four parities. Economic value of this enhanced reproduction was partially offset by slower growth and somewhat fatter carcasses in the progeny of GPK347 dams.

NI Lines Released

A controlled release of breeding animals from the NI line was approved in 1996. An advisory group representing Nebraska pork producers and several breeding organizations developed the guidelines by which the line would be made available to breeding organizations.

The first release occurred in 1997 to a breeding organization in Brazil known then as Granja Rezende S.A. Over the next two years, pigs were released to 10 additional breeding organizations including Newsham Hybrid, Monsanto Choice Genetics, Cotswold Pig Development Company, Premier Swine Breeding Systems, Hermitage Exports Ltd., Danbred North America, National Genetic Technology, two private breeders in Nebraska (Waldo Farms, C. Papenhausen), and a consortium of Iowa-Missouri breeders (B. Sleazer, P. Howerton).

Table 2. Mean Performance of Nebraska Index (NI) Line Cross Females Across Herds
Trait No. herds No. records Mean Range (min. and max. herd means)
Age at 1st service, days 1 679 219
Farrowing rate, % 15 4,261 82.1 62.5 - 90.9
Total born/litter 15 4,569 12.3 10.9 - 13.8
Pigs born live/litter 15 4,569 11.2 10.0 - 12.4
Pigs weaned/mated female/year 8 1,973 22.6 20.8 - 26.2
Weaning-to-service interval, days 11 5,811 8.2 5.9 - 11.5

Most organizations obtained pigs of one sex only or obtained small numbers of pigs of both sexes. Monsanto sampled significant numbers of both males and females and is the only organization to have sampled in a way that will permit the line to be maintained long-term as a pure-line population.

The NI line samples were incorporated into the respective breeding organization lines in a variety of ways, ranging from continued pureline production to development of composite populations.

For the most part, breeding organizations are using their new maternal line composites to produce F1 gilts with either 50% or 25% NI line genes. At this point, a significant number of these crossbred females have been tested in commercial herds and a limited amount of information is available.

NI Line Genetics Field Data

No official data are available on the number of herds or sows of NI line descent being used in the industry. The performance data available from commercial herds are presented in Tables 1 and 2.

Table 1 compares the performance of females with NI line cross genes with standard cross females across six herds in which both types of females were contemporary. Average parity of females was approximately 1.6 for NI line cross females and 1.8 for standard cross females. The “means” are weighted averages across parities and herds.

The data shows NI line cross females had advantages over standard cross females that ranged from 0.9% for age-at-first service, to approximately 7.5% for litter size. Differences were similar across all parities and are similar to differences between GPK347 females and other crosses found in the MLP test.

Data in Table 2 show the performance of more than 4,500 NI line cross females across 15 herds. These data include production of only NI line cross females with no comparison to other crosses. They should be used only to get a general sense of levels of production being realized with these females in a variety of commercial settings. Considerable variation among herds in all traits existed, which is clearly illustrated by the range in number of pigs weaned/mated female/year, which went from 20.8 to 26.2 pigs.

General Comments

Crossbred females with NI line genes are expressing levels of performance in commercial herds that are very similar to those seen in the MLP results. Improvements in fertility, litter size and rebreeding performance are realized in crosses of this line with a wide range of other maternal lines. Breeding organizations with these pigs are continuing to develop and evaluate not only the maternal performance of the lines, but also the growth and carcass merit of terminal cross progeny.

Pseudorabies Rule Changes

Two states have announced changes in their pseudorabies (PRV) control programs.

The Iowa Department of Agriculture has filed an emergency rule changing the expiration date of the monitored status of a site from six months from the date of last official bleeding to 12 months for movement of swine. Testing requirements for the sale of swine have not changed. Mandatory vaccination of all swine on monitored sites in Iowa continues through March 2003.

Iowa State Veterinarian John Schiltz says the emergency rule was filed because federal funding for enhanced surveillance testing ended Dec. 31, 2002, and routine state funding was cut by 50%. The result is that producers would have been responsible for paying for required six-month monitoring tests on all premises located in Stage II (control).

In Indiana, one-year certification as PRV-free has resulted in relaxed monitoring requirements. Major changes include:

  • Elimination of down-the-road testing;

  • Elimination of change-of-ownership testing for breeding or exhibition;

  • Extension of health certificates from 60 to 90 days; and

  • Permission to ship hogs interstate under specific guidelines.

“The producers and swine practitioners in this state fought this disease for more than two decades,” says John Johnston, DVM, director of the Board of Animal Health's Swine Division. “They deserve to reap the benefits of their hard work and investment in making Indiana PRV-free.”