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Triumph Foods' Blast Raises Questions

Many questions have arisen regarding the possible impact of an explosion Oct. 12 at the new Triumph Foods pork processing plant in St. Joseph, MO. One construction worker was killed, another was seriously hurt and 14 others were treated for less severe injuries. An Associated Press story on Thursday said the blast blew a 150-ft.-wide hole in the roof. In fact, a portion of the roof collapsed as a result of the explosion.

The damage is confined to the administration and cafeteria portions of the plant. The remainder of the plant, including the kill floor, cutting lines, refrigeration and waste treatment areas were unaffected. Triumph management is not at this time predicting how long the delay may be. One source said the plant was due to open in 2-3 weeks.

Five large hog producers and a coalition of smaller producers own the Triumph operation. When the plant opens, the hogs that those groups are currently sending mainly to upper-Midwest plants will be redirected to St. Joseph, creating a need for hogs on the part of former purchasers.

This plant was not yet a factor in cash hog markets, but was probably already having an effect on marketing contract offers in the upper Midwest. Packers need dependable supplies, and the packers losing this supply source have no doubt been trying to secure hogs to replace those currently purchased from Triumph owners.

Market analysts (including me) have considered the possible impact of the Triumph plant on hog prices in 2006 and beyond. It is difficult, though, to quantify that impact, and many have chosen to treat Triumph's entry as a risk factor that could positively impact hog prices. We know the factor will be here. We just do not know how large it might be.

Tracking U.S. Hog Slaughter Capacity
Figure 1 shows packing capacity utilization rates and hog prices from 1994 to the present. The utilization rate can go above 100% due to overtime and Saturday operations. These data go back to 1994 simply because no one ever knew the capacity of the U.S. hog slaughter sector before then. The sector had a substantial amount of excess capacity that was slowly wrung out of the business as new companies entered and new, low-cost plants came on line.

The fall of 1994 created the first possible benchmark for U.S. hog slaughter capacity. Anticipating large hog supplies, agricultural economist Ron Plain of the University of Missouri asked me in a September 1994 phone call whether I thought we could run out of room to slaughter pigs that fall. I laughed. Really, I laughed. The idea, after years and years of ample capacity, was that foreign. After computing the effect of closures by Swift (the old St. Joseph, MO, plant) and Seaboard (Albert Lea, MN), I concluded that Plain's concern was very well-founded.

The "mini-crash" of 1994 was, to my knowledge, the first time producers had real difficulties in moving hogs to slaughter. Delays of up to one week and rising slaughter weights confirmed that capacity was an issue - at least in as much as the capacity was less than producers' desires and needs to move hogs at any given point in time.

Of course, 1994 was just a blip compared to 1998. A large increase in production, coupled with some degree of panic-selling as hog prices fell and significantly fewer shackle spaces all added up to producers' worst financial disaster in history.

Packing Capacity Price Impact Lessens
So what about now? Figure 1 shows that the strong, negative correlation between packing capacity utilization and hog prices (it was -.76 from 1994 through 2002) has lessened markedly in recent years. It now stands at -.49 for 1994 through September 2005.

Much of that decline in correlation was due to price patterns of 2005. Even a run above 100% capacity utilization from September to December last fall did not drive hog prices down significantly. Strong consumer-level pork demand and excellent exports kept product moving, and buoyed hog demand enough to offset the negative price effect that high-capacity utilization rates have had in years past.

Slaughter Capacity Growth
What about the future? The new Triumph plant will still add to slaughter capacity in 2006. Hormel's expansion of its Crete, NE, plant is supposed to be operational in December. Smithfield will lose some capacity in Virginia this fall but gain some spots in Iowa in early 2007. I expect capacity to be 7,200 head/day higher (to 415,075) when the Triumph plant comes on line with one shift. A second shift (the timing is not known for certain, but within one year has been mentioned by Triumph principals) would add another 8,000 head/day.

With hog supplies next year expected to be quite similar to this year, those capacity numbers suggest relatively low utilization rates that should support hog prices.

Click to view graphs.

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

Feeding strategies for weaned pigs, sows

Feeding and nutritional strategies for weaned pigs, regardless of age, should be thoroughly reviewed on a regular basis to ensure success of your weaning age program.

Properly designed nutritional programs and feed budgets cannot, by themselves, ensure a successful nursery program.

It's important when moving to an older pig at weaning that nutritional feeding strategies can be modified to maintain growth performance targets and decrease feed cost per pig.

Nursery pig management

Several key management factors are required to maximize growth and profitability of the weaned pig regardless of age at weaning:

Feed and water intake: The factors necessary to maximize feed intake include a warm, draft-free environment, appropriate water and disease control programs.

Newly weaned pigs dehydrate rapidly and must have ready access to drinking water. Whether you are providing water through nipple or bowl drinkers, proper positioning and sanitation of watering devices are essential elements of proper pig hydration.

Also, to maximize feed intake, pigs must be provided unrestricted access to feed. Producers often limit-feed pigs to reduce postweaning diarrhea. However, recent research indicates that limit feeding highly digestible nursery diets actually increases the risk for diarrhea. Thus, limit feeding is a frequent cause of reduced nursery exit weights.

A number of management lapses may also result in limited feed intake. These include failure to investigate all potential contributing areas such as improper air temperature or ventilation settings, poor sanitation or undetected disease challenges.

Social interaction between the piglets while eating is critical to develop feeding behavior. Feeders with solid partitions prevent this feeding interaction because piglets cannot see each other while eating. A properly designed feeder without solid partitions encourages proper social interaction and maximum feed intake, while preventing the small pigs from lying and defecating in the feeders.

Feeding mats are also useful to facilitate social interaction during feeding for the first few days after weaning.

However, mats can lead to higher levels of feed wastage and disease risk from improper sanitation if kept in the nursery pen too long.

Feeder adjustment: Proper and frequent feeder adjustments are the keys to excellent feed efficiency and low feed cost in the nursery. Feeder adjustment must start with the first feed placed in the feeder. Regardless of whether the first diet comes in bags or bulk, the feed gate in all feeders should be closed before placement of the first pellets. The feed gate then should be opened so a small amount of feed is visible in the feed pan.

Avoid placing pelleted feed into an empty feeder with the agitation gate open, because it will result in large amounts of feed filling the trough, leading to feed wastage and difficulty in achieving the proper feeder adjustment.

Although adequate amounts of feed must be present in the feeder at all times after weaning, too much feed in the pan of the feeder can also decrease growth rate.

In an attempt to stimulate feeding behavior, some producers place large amounts of the first diet in the feeding pan. Although the intention is positive, the outcome is negative. Energy deficiency can result from pigs “sorting” the diet and producing a buildup of fine feed particles (“fines”) in the feeding pan that pigs can find less palatable. These fines then lodge in the feed agitator mechanism, making it difficult for new feed to flow from the feeder.

To correct this problem, manage the amount of feed flow in the pan to stimulate the development of feeding behavior. Approximately 50% of the feeding pan should be visible in the first few days after weaning. As the pigs become more accustomed to the location of the feed and adjust their feeding behavior, the amount of the feed in the feeding pan should be decreased rapidly to less than 25% coverage.

Also, feed agitators need to be tested and adjusted frequently to ensure that the buildup of fines does not prevent them from working freely.

Identifying starve-outs: In our experience, weaning an older pig will reduce but not eliminate starve-out pigs. It's essential to have a dedicated workforce who can identify the signs of a starve-out pig, and then gently teach the pig where and how to eat with either a mat or individual feeding system.

Some pigs simply don't start eating readily after weaning — regardless of age. Producers who have the ability to teach these starve-out pigs to eat, rather than treating them with an antibiotic, will save more pigs.

The main signs to help identify starve-out pigs include:
• Mental status — depressed;
• Body condition — thin;
• Abdominal shape — gaunt;
• Skin — fuzzy;
• Appetite — huddled with no activity at the feeder, and
• Signs of dehydration — sunken eyes.

Pen space: One of the largest advantages with later weaning is the improvement in pig growth rate, both in the nursery and finishing stages. For every day of increased weaning age up to 21 days of age, producers should expect pigs to be over 3 lb. heavier from weaning until marketing on a fixed-day system, or marketed 1.7 days faster.

However, nursery pen space must be managed carefully. With a higher initial weight and the expected increase in growth rate, space allotments per pig need to be adjusted accordingly. Pig space will need to be increased if pigs remain in nursery pens for the same number of days before being moved to finishing barns.

In wean-to-finish facilities, this is not a concern unless producers are double stocking during the nursery phase of growth.

Phase feeding and feed budgets

The goal of the nutritional program remains the same regardless of the number of diet phases used. That goal is to transition pigs to a low-cost, grain-soybean meal-based diet as quickly as possible after weaning without sacrificing growth performance. In most cases, pigs achieve this goal without higher-cost products such as whey or fish meal.

A four-phase feeding approach replaced the traditional, three-phase system in the nursery phase when younger weaning ages were implemented in multi-site pig production.

With later weaning, many producers are reevaluating feed budgets or reverting back to the three-phase approach (see Tables 1 and 2).

No matter what feeding strategy is chosen, the concept of matching the digestive capacity of the pig to the ingredients used in the rations should not change.

Table 1: Feed Allowances/Pig (weaning to 50 lb.) for a Four-Phase Feeding Program

 Weaning age, days
Diet, lb. 7 14 21 24
SEW* 5 2 1 -
Transition 5 5 3 2.5
Phase 2 15 15 15 15
Phase 3 50 50 50 50
*Segregated early weaning

Table 2: Feed Allowances/Pig (weaning to 50 lb.) for a Three-Phase Feeding Program

 Weaning age, days
Diet, lb. 21 24
Phase 1 4 2.5
Phase 2 15 15
Phase 3 50 50

Postweaning nutrition and feed budget: As weaning age increases, two different approaches can be used for diets fed immediately after weaning.

Some producers use the same segregated early weaning (SEW) and transition-type diets that were used with younger-weaned pigs, but alter the feed budgets to decrease the amount of each diet fed.

A producer may provide 0.5 or 1 lb. of a SEW diet/pig and 1 to 3 lb. of a transition diet. If the pigs exceed the desired weight target for consumption of these diets, the budget for the subsequent diet is reduced accordingly.

Other producers have replaced the two separate phases with a hybrid Phase 1 diet. This diet is a compromise between the SEW and transition diet on levels of expensive ingredients, such as plasma, and therefore is a compromise on cost.

As weaning ages and weights increase, ingredients such as plasma and lactose — the cornerstones of most SEW and transition diets — can be dramatically reduced.

Another consideration that influences the feed budget is the variability of age at weaning within a group. Large variations in weaning age may require an increased budget amount to ensure that the youngest pigs receive an adequate amount of the proper diet.

Nutrition and feed budget from 15 to 25 lb.: This diet is typically a grain-soybean meal-based diet with 7 to 10% of a high-quality source of lactose and a small amount of a specialty protein source, such as spray-dried blood meal or high-quality fish meal.

Other specialty protein sources may be used, depending on economic considerations or location. Many producers make this diet in meal form on their farms.

Growth-promoting antibiotics and zinc oxide are typically used in this diet. Research indicates that 2,000 ppm zinc is the optimal inclusion level. When zinc oxide is used for growth promotion, high levels of copper sulfate do not provide any additional growth response. Typically, 15 lb. of feed is budgeted for pigs during this phase.

Nutrition and feed budget from 25 to 50 lb.: This diet should resemble a grow-finish diet, which in most cases will be a simple grain-soybean meal diet without any specialty protein products or lactose sources. The digestive capacity of the pig at this weight is such that these ingredients are unwarranted; including them will increase feed cost/pig.

This diet is the lowest-cost diet in the nursery program. However, since consumption of this diet is the greatest during the nursery phase, it usually accounts for more than half the total feed cost from weaning to 50 lb. Typically, 45 to 50 lb. of feed is budgeted for pigs during this phase.

High usage makes it critical to monitor diet costs from 25 to 50 lb. Because long-term feeding of high levels of zinc oxide has not been shown to be beneficial, growth-promotion levels of zinc should not be used in this ration. Copper sulfate at 125 or 250 ppm of a complete diet and the proper antibiotics can serve as effective growth promoters in this phase.

Added fat: The fat level of the diet will depend on the ability of the producer or feed company to economically purchase fat. By increasing levels of fat in nursery diets, pigs will often respond with improvements in average daily gain and feed efficiency. Between 3% to 5% added fat is a common recommendation.

Regardless of the phase-feeding strategy, development of a proper feed budget will help keep nursery feed costs competitive. The feed budget should be used as a target for the amount of each diet that each pig receives from weaning to 50 lb. This budget should be adapted to the weight of pigs on a particular operation after the optimal weaning age is determined.

It's critical to practice strict discipline when using a feed budget to prevent overfeeding of the more expensive nursery diets past the desired weight range. Often, this is the major cause of high feed costs in the nursery.

Ingredient quality

With increasing weaning age, some pigs may be fed only a limited amount of an SEW or transition-type diet that contains higher levels of specialty protein and lactose sources. However, this does not dismiss the importance of using high-quality, highly digestible sources of these products.

While older-weaned pigs have a more advanced digestive tract to digest protein products, they can't utilize poorly processed or heat-damaged ingredients any better than a younger, lighter pig.

The use of high-quality ingredients, such as spray-dried blood meal and lactose purchased from a reputable source can assure producers that ingredient quality is not a limiting nutritional factor in nursery pig diets.

Producers who decide to manufacture on-farm nursery diets in meal form may choose to utilize granular specialty and lactose sources that have better flowability properties. Products with poor flow characteristics can lead to problems with bridging and getting feed out of feeders, thus limiting feed intake.

Don't forget the sows

As lactation length increases, it becomes essential to maximize feed intake to supply adequate levels of protein and energy to the sow. Research is clear, and nutritionists agree, that restricting protein or energy intake during any period of lactation will reduce milk production and impair subsequent reproductive performance. The negative influence on reproduction is particularly evident during summer months and can contribute to seasonal infertility.

The most practical method of increasing energy intake is to increase total feed consumption. However, when feed consumption is problematic, high levels of fat (5% or greater) are sometimes added to lactation diets to compensate for low feed intake.

Because dietary fat is preferentially shifted into milk fat, it doesn't directly help the sow as much as an increase in total feed intake. While high fat levels can help improve litter performance, some research indicates that very high levels (>5% added fat) can impair sow reproductive performance.

Therefore, we recommend that some dietary fat be added to lactation diets, but avoid excess levels in an attempt to compensate for poor lactation feed intake.

While most swine nutritionists and veterinarians agree that maximum feed intake throughout lactation is the correct goal, considerable debate exists as to the proper method to achieve maximum intake.

The debate concerns how quickly feed intake should be increased in early lactation. Some observers advocate feeding extremely low levels of feed (2 lb. or less) prior to and immediately after farrowing. Field experience indicates that extremely low intake during this period limits the ability to increase feed intake rapidly during early lactation.

In extreme cases, ulcers can be created by the extended period of low intake after farrowing. After the long period without feed, sows often overeat if provided free access to feed. The sows then typically go off feed or have a noticeable dip in feed intake.

To compensate for a dip at Days 5 to 10 of lactation, some nutritionists or veterinarians prescribe limit feeding rather than correcting the management that originally caused the problem (the extended period of little or no feed intake prior to and immediately after farrowing).

We recommend that just before farrowing, sows be fed at least 4 lb./day to prevent excess body condition loss, regardless of lactation length.

Feeding first-parity sows

First-parity sows require special consideration when formulating lactation diets for two reasons:

First, their level of feed intake is typically about 20% less than the herd average. If the average sow is consuming 12 lb./day, first-parity sows will average about 10 lb. per day. So first-parity sows require approximately 0.20% higher lysine lactation diets to maximize litter weaning weight.

Second, researchers have demonstrated that first-parity sows can require higher lysine levels for maximum reproductive performance than required for maximum milk production.

When segregated-parity sow farms are used, a separate diet can be provided for first-parity sows. But when segregated-parity flow is not an option, nutritionists and producers must decide to either provide higher amino acid levels than required by the older sows in order to meet the requirements of young sows, or to formulate diets closer to the requirements of the older sows, and not meet the requirements of the young sows.

Typically, we advocate formulating diets closer to the requirements of the young sows and oversupplying nutrients to the older sows. Small improvements in reproductive performance of young sows rapidly pay for the added feed cost in the older sows.

Feeding for sow condition

We recommend that sows be fed at least three times/day to assure that they have a constant supply of fresh feed available. As weaning age increases, and feed consumption increases in the later stages of lactation, this practice cannot be emphasized enough.

To minimize sow body condition loss, feeding sows to maximum feed consumption, especially in the later stages of lactation, is critical to future reproductive success and longevity.

While research data is sparse in documenting the benefits of high feed intake levels after weaning and prior to breeding, we recommend that sows be fed to consume as much feed as possible during the period from weaning to rebreeding. High intake in this period, however, won't make up for increased losses of body reserves resulting from low feed intake during lactation.

Creep feeding

The effectiveness of creep feeding is an area open to considerable debate. During the past decade, providing creep feed to early-weaned pigs typically has not been advocated.

However, with older-weaned pigs and longer lactation lengths, this practice, if properly managed, can help alleviate pressure on the sow while helping pigs get off to a more rapid start in the nursery.

For creep feeding, supplying a high-quality starter diet equivalent to a SEW diet for earlier-weaned pigs is sufficient. Creep feed must be kept fresh and in feeders or troughs that prevent excess wastage.

Even though only small amounts are actually fed, the cost of creep feeding, if not managed properly, will increase the cost/weaned pig beyond the returned benefit.

Also, supplying pigs with an easily accessible water source can aid in pigs becoming accustomed to drinking water before they enter the nursery.


The basic concepts and management practices for feeding older-weaned pigs are not different than those for younger weaning ages. Intense management of newly weaned pigs to get them started on feed as soon as possible is critical to the success of the nutritional program.

Ultimately, producers who have high nursery feed intake, follow strict nursery feed budgets, use high-quality ingredients and maximize sow lactation feed intake will also maximize profitability.

Health Aspects Of Different Weaning Ages

Weaning age in baby pigs has seen its ups and downs over the years in U.S. pig production. Recently, we've seen a trend toward stabilizing and increasing weaning age in many sow farms (Figure 1).

The South Central Veterinary Associates database, representing clients across southern Minnesota and north central Iowa, has shown a decrease in the number of sows/farrowing crate over the past two years, reflecting the move to older ages at weaning.

The changes that have occurred with pork production in general, and as a result of the switch to older weaning age in particular, raise five key questions that must be considered:

  1. Do preweaning mortality levels increase as weaning age increases?

  2. What is the impact of weaning age on the incidence rate of sickness and death loss in the nursery?

  3. Have there been any negative health consequences as a result of the trend to earlier weaning that developed over the past 25 years?

  4. How much has weaning age been influenced by barn limitations and economics?

  5. Do all infectious agents respond in a positive way when pigs are weaned earlier?

Weaning Age Effect on Preweaning Mortality

All indications from research and field data, up until a few years ago, are that in many cases, decreasing weaning age allowed for a healthier pig at weaning. At the same time, conventional wisdom suggested that as weaning age decreased, so did preweaning mortality (PWM).

In fact, a review of the U.S. and Canadian databases in the PigChamp recordkeeping system shows no direct correlation between average age at weaning and PWM (Table 1).

One explanation for this apparent contradiction is the high percentage of mortality that occurs within the first 14 days after farrowing (Table 2). If 6% of the total PWM is occurring after 14 days of age, this accounts for only 0.066 pigs/litter weaned (assuming an average of 11 pigs born alive/litter with a 10% PWM).

As farrowing facilities and management techniques have improved, any negative impacts on PWM associated with weaning age seem to have been eliminated.

Segregated Early Weaning Programs

Swine health innovators, such as the late Al Leman, DVM, helped the industry understand the true benefit of all-in, all-out production. Emptying rooms, barns and, ultimately, production sites, could make large linear gains in health.

Work by researchers, including swine veterinarians Tom Alexander of the United Kingdom, and D.L. (Hank) Harris and Barry Wiseman of the United States, has shown the positive contributions of segregated early weaning (SEW) on elimination of some known swine disease agents (Table 3 on p. 20).

Table 1. Historical PigChamp Wean Age vs. Prewean Mortality (PWM)
United States Canada
Wean Age, Days Percent PWM Year Wean Age, Days Percent PWM
18.0 12.4 1999 20.9 11.9
18.0 12.4 2000 20.9 11.9
18.3 13.8 2001 20.8 12.1
18.2 13.1 2002 20.6 11.6
18.2 13.4 2003 20.6 12.4
18.2 12.5 2004 20.4 11.6
18.6 12.0 1st half ‘05 20.0 12.1
Table 2. Percent of Recorded Deaths by Wean Age*
Age 0-3 Days 4-7 Days 8-14 Days 15+ Days
Percent Deaths 65 16 13 6
*South Central Vets PigChamp data 2004

At about the same time, the need for improved facility and labor efficiencies began impacting the size of herds. These factors helped foster the development of multi-site production systems throughout the 1980s and 1990s that were very conducive to implementation of SEW programs.

Early Weaning Successes, Failures

The SEW program has proven successful, in some cases, in helping eliminate diseases such as Mycoplasmal pneumonia, swine dysentery, Actinobacillus pleuropneumonia (APP) and pseudorabies.

The management strategies necessary to properly implement early weaning programs are very detailed and require precise implementation. These health strategies are most successful with high-quality facilities, nutrition and management.

Unfortunately, there have been many instances where earlier weaning of pigs has led to higher mortality and disease problems in the nursery. Placing very young pigs into nurseries that do not meet those stringent requirements can quickly lead to disaster.

During the last decade, emphasis has been placed on maximizing throughput of systems and facilities, while compromises have been made to some of the critical control points that make SEW work. Some compromises include:

  • Not understanding the diseases that pigs are being exposed to at the sow farm;

  • Not implementing the proper medication programs prior to weaning and postweaning to help eliminate infectious disease agents;

  • Not sticking strictly to low variation in weaning age when trying to adapt a true SEW program;

  • Weaning pigs into a “motel style” nursery (pigs weaned into different rooms in the same barn) that allows for lateral infections to occur between age groups at one site;

  • Locating too many pigs on one site;

  • Overcrowding pigs in a poor environment;

  • Improper training of nursery personnel to handle very young, weaned pigs;

  • Not feeding pigs the proper diets for their age at weaning;

  • Mixing multi-sourced weaned pigs into one nursery at an early age;

  • Weaning pigs that are shedding the porcine reproductive and respiratory syndrome (PRRS) virus into a population of healthy, early-weaned pigs.

It is important to note that the PRRS virus is an example of an infectious disease agent that has been proven to infect pigs at or around the time of farrowing. It has been clearly shown that early weaning of baby pigs cannot successfully eliminate this virus.

Increasing Weaning Age To Reduce Mortality

As data has accumulated on the positive effect that extending weaning age has on sow performance, producers have begun to realize the potential benefits to health and performance from weaning an older, bigger pig.

It is important to note that there is actually very little science to observe what happens to the health of a population of pigs in a nursery or a wean-to-finish barn when the average weaning age changes on a farm.

In extensive field trials conducted by Kansas State University (KSU) researchers, there was a significant reduction in nursery mortality as weaning age increased (Figures 2 and 3). These differences were measured from a 7,300-sow commercial farm in trials on over 2,000 and 3,000 pigs, respectively, in a uniform environment with one source of pigs. Weaning pigs at less than 15 days of age increased mortality rates dramatically; weaning pigs from 15 to 21.5 days of age resulted in near linear improvements.

The trials concluded that a significant improvement could be made not only in mortality but in average daily gain and pounds sold/weaned pig. Modeling of the two trials showed that for every day added to weaning age, wean-to-finish mortality decreased by 0.47%.

The level of change in mortality expected from increasing weaning age will depend on individual farm parameters such as baseline mortality rates, pig flow and other farm-specific challenges. Farms that are heavily infected with PRRS virus probably will not see substantial changes.

Effect of Weaning Age on Nursery Pigs' Behavior

Recently published work (Journal of Swine Health and Production, September-October 2005, Vol. 13) by the KSU group has shown significant differences in the chronic problem of navel sucking (belly nosing) in weaned pigs. Pigs that were weaned at a younger age had a much higher prevalence of belly-nosing behavior.

The most significant change in rate of belly nosing occurred in pigs weaned at less than 15 days of age. Over 20% of all weaned pigs at 12 days of age showed this detrimental behavior. Only 6% of pigs weaned at 21 days of age had these tendencies.

At the same time, over 30% of pigs weaned at 12 days of age had umbilical lesions. These types of umbilical lesions can lead to bacterial infections and umbilical hernias. Average daily gain in the belly-nosing pigs was 4% less in comparison to the control group.

Overall, the KSU researchers concluded that increasing weaning age and using bowl waterers appear to be the two main management inputs that reduce belly nosing.

Impact of Increased Weaning Age

Over the past few years, a significant increase has occurred in a few diseases caused by bacteria that are found in just about all pigs' mucous populations. This group includes the “suicide” diseases of Haemophilus parasuis and Streptococcus suis.

Carlos Pijoan, University of Minnesota expert on Haemophilus parasuis and Streptococcus suis, has done significant studies on how these two normal mucosal bacteria cause disease.

Pijoan explains that pigs don't always suffer disease when exposed to bacterial agents as young pigs. This is because of a process called colonization.

Pijoan theorizes that baby pigs get colonized with the bacteria while still under maternal protection, which would prevent the bacteria from invading the pig and causing disease.

Disease prevalence and severity has increased with the transition to off-site SEW. In older, conventional farms with continuous pig flow on the same site as the sow herd, baby pigs get infected very quickly from older animals.

Pijoan's work has shown that some disease-causing strains of Haemophilus parasuis and Streptococcus suis require late colonization in an older pig because of their low prevalence in sow herds. In order to produce disease from one of these bacteria, only a few pigs are infected, causing spread to non-colonized pigs in the nursery. A higher prevalence of the virulent or infectious strain of bacteria prior to weaning will not cause disease in the nursery.

Inoculation of baby pigs with live cultures of disease-causing Hemophilus parasuis has proven successful in some cases in reducing disease levels in nurseries. Caution needs to be exercised before trying these procedures, however. Weaning an older pig may play an important role in allowing natural colonization of these two potential pathogens prior to movement to off-site segregated production.

Recent outbreaks of postweaning multisystemic wasting syndrome (PMWS), potentially caused by porcine circovirus Type 2, have been difficult to control.

In certain areas of pig production, such as the United Kingdom and Quebec, Canada, significant nursery mortality has occurred with this disease syndrome. Severity also increases when PMWS cases in Quebec have been linked with the PRRS virus, according to new research presented at the 2005 Leman Swine Conference by Laura Batista, DVM, of the University of Montreal. Field experiences are indicating that increasing weaning age reduces the severity of pigs showing signs of wasting from PMWS.

Table 3. Weaning Age Required to Eliminate Disease Agents
Disease Maximum Wean Age, Days
Pasteurella multocida 8 to 10
Haemophilus parasuis 10
Ileitis 10
Mycoplasmal pneumonia 17 to 21
Porcine reproductive and respiratory syndrome 0
Salmonella 14 to 16
Streptococcus suis 5
Swine influenza virus 21

There are still diseases such as Mycoplasmal pneumonia, atrophic rhinitis and Actinobacillus pleuropneumonia where weaning an older pig may cause an increase in disease prevalence if not properly medicated and vaccinated (Table 3).

Over the next few years, more individualized weaning strategies will be implemented based on recognized scientific methods of disease prevention. Certainly, weaning age will be a cornerstone of those strategies.

What to Look for When Buying Weaned Pigs

Many weaned pigs are purchased on the spot open market in North America today.

While spreadsheets may show potential profit for putting pigs on feed, developing a checklist of items to understand the health of the animals prior to purchasing is critical. This has been commonly referred to as a vet-to-vet consult.

It is important to note that in spite of a thorough investigation before purchasing pigs, unforeseen health problems can arise. Still, the industry standard is that pigs are purchased on an “as is” basis.

Review this checklist before purchasing weaned pigs:

  • Are the pigs being sold because of health problems, such as depopulation/repopulation situations?

  • How many different sites are the pigs coming from? Pigs can be represented as a single source from a “system” instead of from an individual site.

  • What are the demographics of the source site farm (size, location, population, facility type, genetics, pig flow and production data).

  • Who is the herd health veterinarian? Often, the system veterinarian may not see the sale animals. Talking with the local veterinarian may be important to understanding the pigs' health.

  • What health issues has the sow farm dealt with during the past two years?

  • Is testing being done to understand the porcine reproductive and respiratory syndrome (PRRS) status of the sow herd?

  • When was the last PRRS break?

  • What is the level of preweaning mortality? Scour problems could be an indicator of potential nursery problems.

  • What vaccination programs are in place?

  • Has the herd experienced a swine influenza virus break?

  • What is the Mycoplasmal pneumonia status of the sow herd?

  • What other diagnostic tests have been done?

  • What is the track record of this source of pigs? Get reference information on other pigs sold and fed recently.

  • What are the mortality rates in the nursery and finisher?

  • What health problems have been seen? Are there signs of respiratory, enteric, sudden death or central nervous system problems?

  • What have been the performance parameters for average daily gain, feed efficiency and cost per pound of gain?

  • What medications and vaccines have been used in the nursery and finisher?

  • Would the referral party buy these pigs again?

  • Finally, what are the average and range of age and weight of the pigs being sold?

Figure 1. Performance of Two Groups of Weaned Pigs
Weaned Pigs Purchased Avg. Weight In Avg. Weight Out Feed:Gain Feed Cost Cost/Lb. Of Gain Mortality Days On Feed
84,886 13 69 1.64 $9.16 $0.16 2% 56
50,235 10 64 1.66 $9.10 $0.17 2.85% 56

Many systems are now selling weaned pigs on a sliding scale with each additional pound over a base weight bringing $0.50 to $0.75/lb.

What does the purchase weight/age of weaned pigs mean to the physical health of the pig and the financial health of the producer? The average difference in weaning age can be as much as one day per ½ lb. of weight.

A review of two groups of purchased pigs that had a wide variation in purchase weights was conducted. Performance data from 2004 in the South Central Management Services (SCMS) database are summarized in Table 1.


An SCMS evaluation of purchased pigs suggests that weaning weight affects three key elements of production in the nursery:

  1. Death loss on heavier pigs equals 0.85% less death loss.

  2. Feed cost savings on a heavier pig is 1¢/lb. of gain.

  3. Heavier exit weights equal significant financial value.