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Articles from 2003 In December

2003 Swine Research Review

Herd Health and Management Extending Weaning Age Boosts Finishing Efficiency, Pounds Sold

Producers have shortened weaning age to improve pig health and growth performance. Kansas State University (KSU) studies document the impact of earlier weaning age, and show that increasing weaning age up to 21 days improves grow-finish throughput within a three-site system.

In two trials, wean-to-finish average daily gain, mortality rate, average pig gain/days postweaning and pounds sold/pig weaned improved as weaning age increased.

The improvements in growth and livability largely occurred in the 42-day postweaning period. There were also some gains in growth during finishing.

KSU researchers stress that the growth rate improvement as weaning age rises is fairly predictable within a given production system. But the level of improvement in mortality rates is somewhat dependent on baseline nursery mortality rates, pig flow, site or system-specific challenges.

For this study, weaned pigs were derived from a 7,300-sow, three-site farm with single-source weaned pigs flowing into all-in, all-out nursery and finishing sites.

In trial 1, litters of pigs were weaned at 12, 15, 18 or 21 days of age. In trial 2, litters were weaned at 15, 16, 18, 19, 21 or 22 days of age. For trial 2, researchers averaged weaning ages to study: 15.5, 18.5 and 21.5 days of age.

Each trial had four blocks, and each block had four replications or pens on test. Blocks remained intact as pigs were moved from nursery to finishing sites.

Each 8 × 12-ft., wired-floored nursery pen in trial 1 contained an equal number of barrows and gilts. Each pen contained 36 pigs/pen, except for the first block in trial 1 which had 34 pigs/pen. Pigs were placed on a three-phase nursery feed budget. Trial 2 pigs were housed in similar conditions and placed on a nursery feed budget that was more or less complex.

For finishing in trial 1, each 7.5 × 22-ft. pen housed 10 barrows and 10 gilts. For trial 2, 13 gilts and 12 barrows were confined in 9.5 × 22-ft. pens. Finishing pens had partially slotted flooring (2/3 solid, 1/3 slotted).

Table 1. Influence of Weaning Age on Nursery Performance (Trial 1)a
Weaning Age, Days
Item 12 15 18 21
Allotment weight, lb.b 7.6 9.4 10.8 12.7
Regressed weaning weight, lb.c 9.3 10.9 12.6 14.3
Average daily gain, lb.d,e .66 .81 .90 1.05
Average daily feed intake, lb.d,e .94 1.13 1.25 1.44
Feed:gaind,e 1.42 1.39 1.38 1.38
Mortality, % 5.25 2.82 2.11 .54
42-day weight postweaning, lb. 37.3 44.7 49.8 56.9
a2,272 pigs with 34 or 36 pigs/pen (50% barrows, 50% gilts) and 16 pens/treatment or a total of 64 pens on test.
bAllotment weights were taken on all pigs three days prior to weaning.
cPredicted treatment mean weaning weights were calculated by regressing the three-day preweaning weights on a pen basis.
dAllotment weights were used for all growth and efficiency calculations.
eAverage daily gain, average daily feed intake and feed:gain are all calculated with allotted pen weight, 42-day pen weight and pen space days postweaning.
Table 2. Influence of Weaning Age on Finishing Performance (Trial 1)a
Weaning Age, Days
Item 12 15 18 21
Allotment weight, lb. 37.3 44.9 49.9 57.0
Average daily gain, lb.b 1.59 1.60 1.62 1.69
Mortality, % 4.38 5.21 4.79 3.13
Off-test weight, lb. 229 240 247 259
Off-test weight/day of age, lb.c 1.36 1.40 1.42 1.46
Carcass weight, lb.d 197 197 195 202
Yield, % 75.9 75.5 75.6 75.8
10th-rib fat depth, in.e .70 .69 .70 .66
Loin depth, in.e 2.53 2.52 2.57 2.55
Lean, %e 54.6 54.6 54.7 55.0
a1,920 pigs with 20 pigs (10 barrows, 10 gilts)/pen and 24 pens/treatment, or 96 pens on test.
bAverage daily gain = (off-test pen - allotment pen weight ÷ (no. of pig spaces × no. of days on test).
cOff-test weight per day of age = off-test weight ÷ pig age.
dDue to extended transfer to slaughter strategy, comparing carcass weights between treatments was not of interest.
e10th-rib backfat, loin depth and lean percentage measures are all adjusted to a common carcass weight utilizing carcass weight as a covariate.
Table 3. Influence of Weaning Age on Wean-to-Finish Performance (Trial 1)a
Weaning Age, Days
Item 12 15 18 21
Allotment weight, lb. 7.5 9.4 10.8 12.7
Off-test weight, lb. 229 241 247 259
Average daily gain, lb.b 1.28 1.36 1.40 1.51
Mortality, %c 9.39 7.88 6.80 3.68
Average pig gain/days postweaning, lb.d 1.42 1.48 1.51 1.57
Pounds sold/pig weanede 208 222 230 249
aLinking nursery allotment weights and nursery mortality data within treatment and block to respective finisher pen to quantify wean-to-finish performance.
bAverage daily gain = (finisher pen weight sold - (nursery allotment weight × no. of weaned pigs required to place finishing pen)) ÷ (no. of weaned pigs required to place finishing pen × no. of days postweaning).
cMortality = (1 - (finishing pen inventory weighed off-test ÷ no. of weaned pigs to place finishing pen)) × 100.
dAverage pig gain ÷ days postweaning = (off-test weight - allotment weight) ÷ no. of days postweaning.
ePounds sold/pig weaned = off-test pen weight ÷ no. of weaned pigs required to place finishing pen.
Table 4. Influence of Weaning Age and Nursery Feed Budget Complexity on Wean-to-Finish Performance (Trial 2)a
Less Complex Nursery Budget More Complex Nursery Budget
Weaning Age, Days
Item 15.5 18.5 21.5 15.5 18.5 21.5
Allotment weight, lb. 9.0 10.5 12.4 9.0 10.5 12.5
Off-test weight, lb. 246 255 263 248 254 262
Average daily gain, lb.b 1.50 1.53 1.60 1.48 1.54 1.58
Mortality, %c 2.89 3.86 2.20 4.95 2.99 2.77
Average pig gain/days postweaning, lb.d 1.54 1.60 1.64 1.56 1.59 1.63
Pounds sold/pig weaned, lb.e 239 246 257 236 246 255
aLinking nursery allotment weights and nursery mortality data within treatment and block to respective finisher pen to quantify wean-to-finish performance.
bAverage daily gain = (finisher pen weight sold - (nursery allotment weight × no. of wean pigs required to place finishing pen)) ÷ (no. of wean pigs required to place finishing pen × no. of days postweaning).
cMortality = (1 - (finishing pen inventory weighed off-test ÷ no. of wean pigs required to place finishing pen)) × 100.
dAverage pig gain ÷ days postweaning = (off-test weight - allotment) ÷ no. of days postweaning.
ePounds sold ÷ pigs weaned = off-test pen weight ÷ no. of wean pigs required to place finishing pen.

Pen identity was maintained from birth through the packing plant in both trials.

In the nursery phase of trial 1 (Table 1), allotment or starting weights increased as weaning ages increased, and the variation in those weights dropped as weaning age rose. The most weight variation was seen in pigs weaned at 12 days of age.

Nursery performance and 42-day postweaning weight improved significantly as weaning age climbed from 12 days to 21 days. Performance was the poorest in 12-day-old weaned pigs.

Average daily gain, off-test weight variation and off-test weight/day of age during finishing in trial 1 also improved as weaning age increased from 12 to 21 days of age (Table 2).

Table 3 depicts how weaning age also influenced performance for the wean-to-finish period. Increasing weaning age from 12 to 21 days resulted in improved average daily gain, mortality, average pig gain/days postweaning and pounds sold/pig weaned.

Similar results were seen in trial 2 in performance gains and in 42-day postweaning weights as weaning age increased from 15.5 to 21.5 days (Table 4).

During wean-to-finish in trial 2, average daily gain, average pig gain/days postweaning and pounds sold/pig weaned all improved as weaning age rose.

Altering nursery feed budgets in trial 2 based on weaning age did not affect wean-to-finish growth performance.

Overall, the trials did not clearly show that either weaning age or nursery feed budgets affected carcass parameters measured.

An economic evaluation indicated that for each one-day increase in weaning weight, cost of production was reduced by 30¢/cwt. and income over costs increased by 94¢/pig weaned. Thus, increasing average weaning age from 15 to 20 days was projected to increase income over costs by $4.70/weaned pig.

This calculation assumes limited finishing capacity, and that since the pigs weaned at a younger age grew slower, they would be sold at a lighter weight. If younger pigs were allowed to grow more days to achieve a similar market weight as the faster-growing, older pigs, the cost/cwt. was reduced by 18¢ and income over costs increased by 53¢/pig weaned.

Researchers: R.G. Main, DVM; S. S. Dritz, DVM; M.D. Tokach, R.D. Goodband and J.L. Nelssen of Kansas State University. Phone Nelssen at (785) 532-1251; fax (785) 532-7059; or e-mail

Finishing Performance Improved by Sorting Off Heaviest 25%

Removing 25% of the heaviest market hogs from a finishing barn pen provided the most improvement in growth performance and total live weight produced, according to University of Illinois researchers. Sorting off 50% of the heaviest pigs from a pen did not provide additional benefits, they found.

The study involved 1,456 crossbred pigs housed 52/pen in a wean-to-finish, tunnel-ventilated barn. Pigs were placed on test 22 weeks postweaning and remained on test for 19 days.

Four treatment groups were studied:

Group 1 (control group) had no pigs removed, with 52 pigs/pen at 7 sq. ft./ pig.

Group 2 had 25% of the heaviest pigs removed, leaving 39 pigs/pen at 9.4 sq. ft./pig.

Group 3 had 50% of the heaviest pigs removed, leaving 26 pigs/pen and floor space unadjusted at 14 sq. ft./pig.

Group 4 had 50% of the heaviest pigs removed from the pen, leaving 26 pigs/pen, with floor space adjusted to that of the control group at 7 sq. ft./pig.

Removing a proportion of the heaviest pigs from the finishing pens boosted growth performance. Compared to the control group, removing 25% and 50% of the pigs from the group (with no adjustment of floor space) increased feed intake 10.8% and 8.0%, respectively; average daily gain increased 20.6% and 21.0%, respectively; and gain:feed ratio improved 7.7% and 14.3%, respectively.

Table 1. Effect of Removal Strategy at Slaughter on Growth Performance
Removal treatment
Item Control 25% 50% 50% adjusted space, Significant effect of treatments
Weight before removal, lb. 249 251 250 251 No
Weight after removal, lb. 249 244 233 235 Yes
Final weight, lb. 278 279 269 268 Yes
Daily weight gain, lb. 1.45 1.83 1.84 1.66 Yes
Daily feed intake, lb. 6.16 6.91 6.69 6.30 Yes
Gain:feed 0.24 0.26 0.28 0.26 Yes
Total live weight produced, lb. 14,412 14,457 13,968 13,902 Yes

Floor space allowance had an effect on growth performance. Group 4, which had 50% of the heaviest pigs removed and floor space adjusted to 7 sq. ft./pig, had lower feed intake (0.4 lb/day) and grew slower (0.2 lb/day) than Group 3 pigs, which had 50% of the heaviest pigs removed, but floor space unadjusted at 14 sq. ft./pig. Group 4 pigs did grow faster (0.2 lb/day) than the control group (Table 1).

The Illinois scientists concluded that only part of the improvement in growth rate following the removal of pigs from a group was due to the increase in floor space. They suggested that part is due to other factors, such as change in social order and dynamics within the group.

Carcass composition and pigs pulled due to poor health were similar for all treatment regimens.

The four pens of 52 pigs produced total live weight of 14,412 lb., 14,457 lb., 13,968 lb. and 13,902 lb. for treatments 1, 2, 3 and 4, respectively.

Researchers: Jacob M. DeDecker and Mike Ellis, University of Illinois. Phone Ellis at (217) 333-6455; fax (217) 333-7861; or e-mail

Better Gilt Programs Can Boost Sow Reproductive Efficiency

Improving gilt management programs will result in reduced sow replacement rates, improved sow fitness, increased labor efficiency and better space utilization.

To achieve that success, reduce annual replacement rates while still meeting breeding targets. Annual replacement rates on swine operations average 62.9% in the U.S. and 58.7% in Canada, according to PigCHAMP data.

Recent research points to three key elements in good gilt management programs:

  • Implementing a strict selection program that identifies the most fertile animals;

  • Achieving appropriate weights at first breeding to prolong lifetime sow performance; and

  • Minimizing non-productive days (NPD) in the gilt pool.

A selection program must identify the 75-80% of pre-pubertal gilts that best respond to boar stimuli.

Based on earlier research at the Swine Research and Technology Centre, and a current study at Prairie Swine Centre, Saskatoon, the link between age at boar-induced puberty and lifetime performance is being examined in Camborough 22 and L42 gilts. Gilts are exposed to vasectomized boars for 20 minutes daily starting at 140 days of age. Gilts achieving puberty by 180 days of age are named “select” gilts and classified as Early (EP), Intermediate (IP) or Late (LP) for first standing estrus. EP gilts have a recorded heat within 140 to 155 days, IP gilts within 155 to 170 days and LP gilts within 170 to 180 days. Gilts are classified “non-select” (NP) if puberty is not reached by 180 days of age.

“Select” gilts are bred at third estrus regardless of age or weight. To meet breeding targets, most NP gilts are bred with the aid of PG600.

Table 1. Breeding Herd Efficiency Measured as Cumulative Non-Productive Days to Day 30 of Gestation in Parity 2*
Early Puberty Intermediate Puberty Late Puberty Non-Select (No Estrus)
NPD Actual1,2 50.5 58.5 75.5 71.1
NPD Predicted3 41.2 41.4 49.2 69.2
Reduction in NPD 9.3 17.1 26.5 -----
Expected Savings4 $18/60 $34.20 $53.00 -----
*Inclusive in estimated non-productive days (NPD) for each gilt category are days-to-service as gilts, wean-to-service interval, days to culling for gilts not bred or not farrowing, and non-productive days (NPD) for sows culled after weaning their first litter (Prairie Swine Centre and University of Alberta, Swine Research and Technology Centre, unpublished data, 2003).
1NPD calculated from 170 days (days to reach slaughter weight of 264 lb. with an average growth rate of 1.6 lb./day).
2Actual number of NPDs accumulated to Day 30 of gestation of parity 2.
3Predicted number of NPDs if gilts bred at 297 lb. body weight or third estrus.
4Example of a 600-sow unit × 45% replacement = 270 gilts × 120% to meet requirements = 324 gilts × (average of $18.60 + $34.20 + $53.00 = $11,426 (savings/year)).

These breeding results have shown that pregnancy rate, farrowing rate, weaning rate and the percent of gilts rebred after weaning the first litter were lower for NP gilts than for EP, IP or LP gilts (Figure 1, on page 15).

First-litter sows need to weigh 385-396 lb. to protect them from adverse affects of first lactation on subsequent fertility, according to recent research.

This data also suggests that instead of following the conventional wisdom of using age to determine time of breeding, ad libitum-fed gilts should be bred based on weight (297-330 lb.)

If gilts are also “select” (recorded standing heat within a set number of days of direct contact with mature boars), and an upper limit of third estrus for breeding is also required, the number of non-productive days (NPD) will dramatically drop (Table 1).

If one NPD is worth $2/day, University of Alberta data says efficient gilt management strategies on a 600-sow unit will produce savings of $11,426 due to reduced NPDs (Table 1).

Researcher: George Foxcroft, University of Alberta. Contact Foxcroft by phone (780) 492-7661; fax (780) 492-4265 or e-mail

Animal Welfare Performance, Welfare in Stalls Comparable to Group Sow Housing

The performance and welfare of sows in stalls was comparable to that of two other group sow housing systems in a pork checkoff-funded study conducted by the University of Minnesota.

A research team led by Leena Anil, post-doctoral associate at the University's Swine Center, concluded that the stall system provided comparable benefits to sows. But stalls do limit space. Further, as sows grow larger, there is greater potential for injury in the limited space they provide, warns the team.

Group sow housing with electronic sow feeder (ESF) offers great potential for providing proper animal welfare provided changes can be made to reduce injuries inherent in the system.

Table 1: Median and Range of Total Injury Scores and Mean ± Standard Error of Cortisol Concentration (ng/ml.) of Sows at Different Stages of Gestation in Pens with Electronic Sow Feeding (ESF) and in Stalls*
Preweaning Day 5 Mixing-1 Mixing-2 Day 28 Day 56 Day 84 Day 108
Total injury scores (pens with ESF) 4(1-11)a 25(9-41)b 22(10-40)bc 21(9-38)cd 18(7-34)e 19(7-39)de 20(7-38)cd
Total injury scores (stalls) 5(1-11)a 5(1-16)a 5(1-14)a 4.5(2-14)a 5(2-13)a 6(2-13)b
Cortisol (pens with ESF) 0.5399 ± 0.087a 4.1227 ± 0.535b 3.1404 ± 0.419bc 2.4883 ± 0.233c 2.1117 ± 0.248c 3.1271 ± 0.477bc 4.2388 ± 0.576b
Cortisol (stalls) 1.2109 ± 0.1230a 1.0166 ± 0.1501a 0.4442 ± 0.06651b 0.4518 ± 0.1291b 0.5258 ± 0.06651b 0.9515 ± 0.1216a
a,b,c,d Within each row, values with different superscripts are significantly (P<0.05) different.
*The injury scores were based on frequency and severity of wound on different body locations (ranging from 0 to 3; no injury, mild, obvious and severe, respectively) and the scores were totaled. A higher cortisol concentration is suggestive of increased stress compared to the lower concentration, though there is no base level.

The third sow housing system tested, hoops with deep-litter bedding, holds promise. But in the small group system tested (15 head/pen), sow handling becomes more labor intensive in terms of management and manure removal, according to the Minnesota team.

The first study compared sows housed in stalls with sows housed in pens with ESF. Welfare status of the group-housed sows in terms of number and severity of injuries and salivary stress hormone (cortisol) concentrations were consistently lower than that of the stall-housed sows. Results are shown in Table 1. Overall production performance was better for sows in stalls than for sows group-housed with ESF.

In the first study, researchers compared 206 Parity 1-4 pregnant sows grouped-housed with ESF in pens 43 ft. long and 22.5 ft. wide on fully slotted floors, with 176 pregnant sows of Parity 1-5 in conventional sow stalls.

Group sows with ESF were housed 38-39/pen. To achieve this size, sows were added to the pen twice, two weeks apart. Sow welfare was assessed four days before weaning and at different stages of gestation. Sows in pens were assessed on Days 5, 19 (both mixing days), 28, 56, 84 and 108 of gestation. Sows in stalls were assessed on Days 5, 28, 56, 84 and Day 108 of gestation.

The concentration of stress hormone in saliva and injury levels in sows housed in pens with ESF was lowest prior to weaning and highest during mixing days. After mixing, both injury levels and stress hormone levels gradually declined before increasing during late gestation. More injuries were observed on the neck, shoulder, chest, croup and limbs. The same trends were observed in stall-housed sows. Most of the injuries were at the back, limbs and udder area.

Injuries and stress levels were lower at all stages of gestation for sows housed in stalls. As parities increased, the chance for injury rose in stalls and declined in group sows with ESF.

Stalled sows enjoyed higher farrowing rates and lower culling rates than sows housed in groups with ESF. Litter size, born alive and stillborns were the same for both groups. Stall-housed sows had fewer mummies, while sows in pens with ESF had fewer piglet deaths and lower preweaning mortality. Lameness was the most common cause of removal in sows housed in pens with ESF.

The Minnesota team states the

product news

Pig Flooring

Dura-Trac welded, steel rod truss frame flooring comes complete with a plastic coating to conserve pigs' body heat and reduce stress caused by cuts and abrasions. The plastic-coated steel flooring provides more durable wear than all-plastic flooring. The truss frame design dramatically reduces installation cost, requiring little or no maintenance. The flooring spans manure pits up to 10 ft. wide, comes in 30-in. widths and accommodates pigs up to 60 lb.
(Circle Reply Card No. 101)

Estrus Synchronization Product for Gilts Approved

Intervet Inc. recently announced the launch of Matrix, the first product approved for estrus synchronization in mature, cycling gilts. The active ingredient, altrenogest, is a synthetic progestagen that mimics progesterone to block follicular development and suppress heat. When withdrawn, follicular development commences, leading to estrus and ovulation. Treatment is recommended only in gilts that have completed at least one estrous cycle.

The product is spray applied with a special device that delivers a fixed 15 mg./dose. A snap-on, quick-coupling connector is specially designed to fit the 1,000 ml (30 oz.) bottle, enough to treat 10.5 gilts for 14 days. Cost per gilt treated for the 14-day period is about $20.50. Individual housing is recommended to ensure gilts receive the proper dose.

Research has shown that when gilts were fed 15 mg. of altrenogest daily for 14 consecutive days, up to 85% displayed estrus within 4-9 days after withdrawal.

The company says the product improves breeding herd efficiencies through better scheduling of boar semen delivery to maximize potency and offers more efficient gilt pool management with greater emphasis on selecting only the best genetics, and fewer gilts are needed to match breeding dates with production schedules.
(Circle Reply Card No. 102)

Combination Vaccine

Boehringer Ingelheim Vetmedica Inc. launches Ingelvac HPE-1, a combination vaccine for prevention and control of Haemophilus parasuis (HPS) and erysipelas. The single-dose product provides extended duration of immunity to 23 weeks against erysipelas and 19 weeks against HPS. Pigs 3 weeks of age and older should be vaccinated with a 2-ml. dose intramuscularly. The vaccine provides equal to superior protection of two-dose products due to superior production techniques and an Impran adjuvant.
(Circle Reply Card No. 103)

Emergency Curtain Drop

Controltech has developed PowerDrop, a new time-delay emergency curtain drop. The curtain drops automatically during a power failure. It features a five-minute drop delay, spring-loaded forced release, instant manual reset, battery-free operation, epoxy-sealed electromagnet and stainless steel construction.
(Circle Reply Card No. 104)

Compact Utility Tractor

AGCO introduces the new GT series 45- to 73-PTO hp tractors to complete the AGCO line. Whether 2WD or 4WD or cab or platform configuration, the GTs offer the perfect balance of power to weight and a turning radius of 10.5 ft. The series includes the GT45, GT55, GT65 and GT75 and features 3- and 4-cylinder engines with SynchroShuttle transmissions with four speed ranges (16 forward, eight reverse speeds) and push-button controls for PTO, all-wheel drive and differential lock.
(Circle Reply Card No. 105)

Wet-Dry Tube Feeder

The new Thorp “ultimate” wet-dry tube feeder is virtually maintenance-free. The waterline is adjustable and the vacuum valve maintains a constant water level for pigs of all sizes without any nipples to leak or adjust. All water trays are connected to one vacuum that fills all of the trays regardless of tube feeder size.
(Circle Reply Card No. 106)

Feed Batching System

Agtronix announces the release of its FS320 Feed Batching System. The rugged, dust-tight unit controls loading of feed ingredients into new or existing feed mixers on a weight basis using the built-in digital scale. The unit stores up to 100 recipes, sequentially runs up to 30 batches and can unload to up to 20 locations. Complete feed records are maintained and can be transferred to a personal computer running Windows software.
(Circle Reply Card No. 107)

Center Pivot Control

Valmont Irrigation announces the cams Pocket Pro, a personal digital assistant (PDA) with cell phone capabilities that allows producers to monitor and control their center pivots. The Pocket Pro is designed with the user in mind, providing simple, intuitive, easy-to-use graphics. A phone link is used at the pivot point, which communicates with the irrigation control panel. The operator using the Pocket Pro calls the phone link, and the PDA provides the screens to see the status and control the functions of the irrigation equipment.
(Circle Reply Card No. 108)

Information Alliance and its eHarvest division and PigCHAMP subsidiary have entered a long-term relationship to provide information and database management services to VeriPrime Pork.

“VeriPrime Pork is a revolutionary cooperative owned and directed by pork producers that will enable them to provide preharvest production and safety assurances to the consumer, and be paid for providing them,” says David Farnum, DVM, vice president of

VeriPrime Pork ( will offer standardized animal welfare and traceability capable of supporting evolving retailer needs, including country-of-origin labeling.

Influenza Virus Mutates, Survives

Despite the swine industry's continued push to achieve greater efficiencies using multiple-site production systems, disease challenges seem to prevail. One ongoing challenge that has definitely managed to change with the times is swine influenza virus (SIV).

SIV, much like its human counterpart the past several years, apparently has developed a somewhat unique ability to mutate very rapidly.

In my practice, it seems as though I isolate one strain subtype on a producer's farm, and a mutant subtype pops up that may or may not be antigenically different. An antigen is a protein, toxin or enzyme that is capable of stimulating an immune response. This activity makes controlling the virus very difficult.

Case Study No. 1

I was called out to a 1,000-head finisher site with primary complaints of pigs off feed, coughing and very lethargic. The double-curtain-sided, slotted floor barn with a 10-ft.-deep manure pit is operated on an all-in, all-out (AIAO) basis. The barn was being filled from two sow herds.

The pigs weighed approximately 160 lb. and exhibited a dry, hacking cough. The producer had lost two pigs during the night and necropsy revealed secondary Streptococcus suis as the main cause of death.

The problem started a week earlier when a curtain cable broke and the barn temperature had dropped to below 55 °F.

The pigs were placed on water medication to stop death loss.

Diagnostics were conducted on lung samples, serum samples and nasal swabs from acutely sick pigs.

As a result, the sow herds were vaccinated with a commercial SIV vaccine and a killed, autogenous porcine reproductive and respiratory syndrome (PRRS) vaccine prior to farrowing.

SIV was isolated from the lung tissue and an autogenous vaccine was developed to vaccinate sows prior to farrowing. The entire breeding herd was double vaccinated with a new SIV vaccine three weeks apart. Incoming gilts were also double vaccinated three weeks apart during the isolation/acclimation period.

The finisher death loss stopped and the cough subsided after 7-10 days. When the finisher was emptied, it was cleaned and disinfected. The finisher was refilled and has not suffered another SIV outbreak.

Case Study No. 2

The second case study involves a multiple-site system where the sow herd is separate from the rest of the production. However, the nursery and finishing operations are all on one site. The nursery is operated on a continuous-flow basis with six rooms of pigs. The finishers are operated AIAO, by building.

The sow herd is vaccinated with a killed PRRS vaccine, along with the routine vaccinations for reproductive problems.

The sow herd broke with abortions and high fevers, and sows were off-feed. The outbreak was sporadic throughout the herd, but primarily occurred during late gestation.

Fetuses were submitted, along with nasal swabs and serum samples. Before the diagnostic test results were fully completed, the nursery and finishers broke with a severe cough. Death loss was minimal.

Necropsy of pigs from the nursery and finisher revealed Strep suis and a few Haemophilus parasuis organisms as secondary invaders. Water medication and individual pig treatments minimized death loss.

Lab tests of the sows revealed normal vaccine titers, but unstable SIV titers. Convalescent serum samples have been submitted. Virus isolation for PRRS and SIV were negative. The herd has since quieted down.

Case Study No. 3

This is the most difficult case of all since it involves a single-site system. This is a 600-sow herd that is positive for PRRS and SIV. The sows are vaccinated before farrowing with killed products, but the nursery and finishers receive no vaccinations.

The sow herd has been stabilized for some time now, but the nursery and finisher broke with a severe cough. The combined death loss in the nursery and finisher was 8%. Death loss was mostly due to Strep suis and Haemophilus parasuis. Water medication stopped death loss, but several pigs turned into culls. A few pigs died of gastric ulcers from being off feed.

Diagnostics revealed a different subtype of SIV. The isolate was added to the sow herd vaccine protocol.

An accurate diagnosis of swine influenza is difficult, at best, and the overall control of the virus is even more difficult.

Stabilization of the sow herd is the key to control. Unfortunately, vaccination does not always guarantee protection since the number of variant subtypes continues to increase.

Area spread and the realization that there is an interdependence between systems helps us establish databases within sow herds.

Challenges for 2004

As 2003 draws to a close, there are a couple of unresolved issues that will spill into next year's pork industry agenda. Leading the list is the future of the pork checkoff.

In all likelihood, within the next 12 months we will know more about the true fate of the pork checkoff. Pork's not alone in the checkoff battle. Thirty-one other commodity checkoff programs are currently being challenged at various levels. In most cases, the key issue focuses on First Amendment rights/free speech infringement. In other words, some producers feel they should not have to pay for generic advertising or other checkoff-funded programs they disagree with.

Appellate Courts have ruled on several cases, including the pork and beef checkoff programs, declaring them unconstitutional. The Sixth Circuit Court of Appeals upheld a Michigan court judge's decision earlier this year that declared the pork checkoff is unconstitutional.

Pork checkoff advocates now have two options:

  1. Request a rehearing from the full panel of six Sixth Circuit Court judges, or

  2. Request a “stay” allowing the checkoff to continue while an appeal is filed with the U.S. Supreme Court.

The Supreme Court hears only 5-6% of the cases brought before it, so there is no guarantee the checkoff appeal will be placed on the docket. However, with a constitutionality issue at the center of the debate, some feel the High Court justices are more likely to accept an appeal. Some are betting the beef checkoff will be the test case.

With so many checkoff programs literally hanging in limbo — I sure hope the Justices hear a case. The pork industry and many other segments of agriculture need a definitive decision.

In the meantime, it would be foolhardy to assume the checkoff will go on as is. The Justices may agree with the lower court rulings and banish all commodity checkoff programs. Or, they may agree that the laws regulating checkoff programs must be rewritten to exclude generic promotion programs. Of course, they also could rule that checkoff programs may continue as is.

Without question, the challenges facing the pork industry are increasingly legislative or regulatory in nature. At last year's Pork Industry Forum, several states presented resolutions calling for lowering the mandatory checkoff rate. The underlying thought — a reduction of the mandatory rate would result in more producers voluntarily reallocating those monies to an unrestricted fund. A good deal of debate ensued. The 172 Pork Act delegates, responsible for setting the checkoff assessment rate, held fast to the 40¢/$100 rate.

However, with key legislative and regulatory battles being waged at all corners of the country, I suspect the checkoff rate debate will recur at several state association meetings again this year, with resolutions for a rate change back on the Pork Forum table in March.

Regardless of the Supreme Court's decision to address the checkoff conundrum, producer-funded organizations (mandatory or voluntary), are obliged to meet the needs and wants of the membership. The Justices may formally decide the fate of the checkoff, or, producers may chose to realign their funding priorities. Either way, a failure to plan ahead would be the greatest miscue of all.

North American Sow Herd

It's high time that producers on both sides of the U.S.-Canadian border cultivate a greater understanding of the scope and interaction between their respective industries.

For all practical purposes, the U.S. breeding herd has stabilized and it's the smallest it's been in modern times.

The biggest cuts have come in the leading hog state, Iowa, where the sow herd has been cut by one-third in the last 8-9 years. But, Iowa producers imported 14.5 million feeder pigs for finishing in 2002. Where did they come from? Missouri and Canada.

Second-ranked North Carolina's sow herd has stood at about one million for several years, a reflection of the ongoing moratorium on new hog buildings.

Meanwhile, in the five-year stretch from '97 to 2002, Canada boosted the number of pigs farrowed by 45%; number of pigs exported increased 62%. Canada exports 20% of their production.

Considering the impact the Canadian hog and cattle markets have had on U.S. hog prices this year, it shouldn't be too difficult to persuade pork enthusiasts on both sides of the border to pay greater attention to what each other is doing. Failure to do so will leave us all limping along with very tight margins and more tough economic times ahead.

There are opportunities for Midwestern producers to get out from under inefficient breeding and farrowing facilities, yet continue to add value to their abundant corn and soybean crops through finishing Canadian-born feeder pigs. It makes perfect business sense, and, in the end, the total North American sow herd can be better matched to domestic and foreign demands.

COOL Passage Blocked

The controversial plan to impose country-of-origin labeling (COOL) on the U.S. livestock industry has been blocked until Sept. 30, 2006 by the recent filing of the fiscal year 2004 Omnibus Appropriations Bill, says National Pork Producers Council (NPPC) President Jon Caspers. Congress is expected to approve the bill.

Delaying implementation of COOL for two years provides time for further study. “While NPPC continues to oppose mandatory COOL, the two-year time out period should give all parties ample time to create a voluntary, market-driven framework,” says Caspers, a Swaledale, IA, pork producer.

He adds: “We must now work to resolve the many problems with mandatory COOL — its failure to raise hog prices long-term, exemptions for chicken and turkey products, a reduction in record U.S. pork exports, and the fact that less than 50% of pork products would be covered.”

NPPC will work with the Agriculture Department and Congress to mandate an animal identification system. Once in place, NPPC will work toward a voluntary program.

Also, now that Congress has blocked COOL, NPPC will deal with increasing imports of Canadian hogs and feeder pigs, which are negatively impacting U.S. hog prices, says Caspers.

Niche Pork Web Site

Producers who sell pork direct from their farms can list their business for free on the pork checkoff's new Niche Pork Web site.

The site ( connects producers, packers and buyers across the country, says Scott Long, Manteca, CA, pork producer and National Pork Board member.

The site also includes niche pork links to universities, Extensions, the U.S. Department of Agriculture and the National Pork Board.

To contribute to the site, call the Pork Service Center at (800) 456-7675.

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