NEW STRATEGIES FOR COCCIDIOSIS MANAGEMENT

NUMBER 7

SPAH-PBU-288

PLUSIRREFUTABLE EVIDENCECOCCI CONFIDENTIALTECHNICALLY SPEAKINGCOCCI FAQS: ANSWERS TO YOUR QUESTIONSCOCCI VACCINATION TAKES HOLD IN CHINA

IDENTIFYING VIABLE, SPORULATED OOCYSTS IS KEY TO QUALITY

KNOW THE SPOREKNOW THE SPOREIDENTIFYING VIABLE, SPORULATED OOCYSTS IS KEY TO QUALITY

NEW

Performance

American Scientific Laboratories, Inc.

Dear Partner in Poultry Production:

Last year, while reporting on the success of Clinacox® (diclazuril), we reminded the industry

to use this new-generation anticoccidial judiciously to minimize the development of resist-

ance. We also mentioned having trials underway to help us formulate more precise recom-

mendations for an integrated, multi-product anticoccidial program – one that would help

restore the anticoccidial sensitivity of Eimeria spp. populations.

Working with a major US poultry company, we chose three complexes that had used

Clinacox in either a continuous or shuttle program for at least one cycle during the prior

year. Coccivac®-B – our live-oocyst coccidiosis vaccine that has been shown to seed houses

with sensitive strains of Eimeria – was used for two full cycles.

We then compared the sensitivity of the field Eimeria spp. populations to Clinacox before and

after Coccivac-B usage, in addition to analyzing and categorizing the sensitivity of the coc-

cidial isolates to Clinacox. The dramatic results:

This study confirmed previous research showing the unique ability of Coccivac-B to restore the

efficacy of in-feed anticoccidials – in this case, Clinacox. Based on previous field observations

and this new information, we continue to recommend using Clinacox for only one cycle annually

or in shuttle program (starter or grower ration, but not both) in two sequential cycles. Coccivac-

B can be used for two to three cycles in an annual rotational program with Clinacox.

For more information, please contact your rep or call us today at 1-800-219-9286.

Sincerely,

Rick Phillips, DVM

Director, Poultry Technical Services

0%

20%

40%

60%

80%

100%

Coccivac is a registered trademark of Schering-Plough Animal Health Veterinary Corporation. Clinacox is a registered trademark of Janssen Pharmaceuticals.Copyright 2003 Schering-Plough Animal Health Corporation. All rights reserved.

FEATURES

3

NUMBER 7

4 COCCI R&D IRREFUTABLE EVIDENCENew study validates theory that vaccinating with Coccivac-Brestores Eimeria sensitivity to diclazuril

6 COVER STORY KNOW THE SPOREIdentifying viable, sporulated oocysts key to a quality coccidiosis vaccine

8 COCCI CONFIDENTIAL VACCINE CONTROLS COCCIDIOSIS, IMPROVES PERFORMANCE IN INTEGRATOR’S CONTROLLED STUDY

10 COCCI FAQS

Schering-Plough’s tech service team answers questions about managing coccidiosis in broilers

12 TECHNICALLY SPEAKING GUEST AUTHOR PROVIDES TECHNICAL INSIGHTS ON MANAGING COCCIDIOSIS IN BROILERS

16 COCCI PROFILE COCCIDIOSIS VACCINATION TAKES HOLD IN CHINAMore producers accepting concept of biological prevention

18 COCCI NEWS Updates from industry

23 COCCI VIEWS Putting ideas to the test

PAGE 4

PAGE 16

Coccivac is a registered trademark and Paracox and Spraycox are trademarks of Schering-Plough Animal Health Corporation. Clinacox is a trademark ofJanssen Pharmaceuticals.

PAGE 6

4

IRREFUTABLE EVIDENCENew study validates theory that vaccinating with Coccivac-B restores Eimeria sensitivity to diclazuril (Clinacox)

Along-held theory that vaccinat-ing with Coccivac-B for just twocycles restores Eimeria sensitiv-

ity to the new-generation in-feed anti-coccidial diclazuril (Clinacox) was vali-dated recently in a large-scale field trialwith a major US poultry company.

The results, according to poultrydisease specialists involved in thestudy, could change the broiler indus-try’s strategy for managing coccidiosis,a costly parasitic disease in poultry.

Previous investigations intothe relationship between coccidiosis vaccination andin-feed anticoccidials —including studies by well-known researchers Dr. DavidChapman of the University ofArkansas, Dr. Harry Danforth,USDA, and Dr. Greg Mathis ofSouthern Poultry Research inAthens, Georgia. — havedemonstrated that vaccinatingwith Coccivac-B restores anti-coccidial sensitivity in a poul-try house by replacing resist-ant Eimeria organisms withones still sensitive to in-feedanticoccidials used today.

“In addition, pen trialsover the years have indicatedthat Coccivac-B used in arotational program can effec-tively displace wild fieldstrains of coccidia and restoresensitivity to the current in-feed anticoccidials,” says Dr.Rick Phillips, director ofworldwide poultry technicalservices, Schering-PloughAnimal Health.

Those studies, however,

focused on ionophore anticoccidials,not on diclazuril, now a widely-used,chemical anticoccidial.

“Despite the research and all thefield reports in hand, we felt it wasimportant to test our hypothesis in thefield where the proverbial ‘rubbermeets the road’,” Phillips says. “Theselatest trials with diclazuril without adoubt prove our hypothesis.”

Study background and designThe study, sponsored by Schering-Plough Animal Health, was conductedat the site of a large US integrator.Independent investigators involved inthe trial were the poultry company’sveterinarian and Dr. Mathis of SouthernPoultry Research, who conducted sen-sitivity testing.

The integrator, which asked not tobe identified in this report, addedCoccivac-B to its anticoccidial rotationto see if using the live-oocyst vaccineimproved the effectiveness of diclazuril— or changed the coccidial populationto one more sensitive to diclazuril — aswell as conventional ionophores. Themove was part of a concerted effort bythe company to develop new tools andlong-term strategies for managing coc-cidiosis.

The poultry company first collectedlitter samples from eight farms involvedwith its seven complexes to obtainbaseline diclazuril sensitivity informa-tion. Prior to this, the complexes hadbeen on a variety of in-feed anti-coccidial rotation programs, all ofwhich included diclazuril for one totwo cycles the previous year, he says.

Dr. Charlie Broussard, worldwidepoultry technical services manager for Schering-Plough Animal Health,

COCCI R&D

Dr. David Chapman

Dr. Harry Danforth

5

explains that after collecting initial littersamples, four of the seven complexescontinued their annual rotation usingionophores or chemical-ionophoreshuttle programs. The remaining threecomplexes incorporated two cycles ofCoccivac-B vaccine into the annualrotation. Identical houses were re-sam-pled after two cycles of Coccivac-B oranticoccidial rotation.

To determine diclazuril sensitivity,Mathis looked at weight reduction andcoccidial lesion scores in test birds andcompared them to unchallenged con-trols. He then summarized diclazuril’sefficacy as “good,” “moderate” or“poor.”

“Even though diclazuril was given arest, diclazuril sensitivity did notimprove or improved very little in thecomplexes that rotated diclazuril withother in-feed anticoccidials, rather thanwith the vaccine,” Broussard says. “Onthe other hand, diclazuril sensitivityimproved significantly in the complex-es that used two cycles of Coccivac-Bin the rotation. Not one of the samplestested scored ‘poor’ for sensitivity fol-lowing Coccivac-B use.” (See Figure 1.)

A few highlights from the trial fol-low, according to Broussard:• In one complex, diclazuril sensitivitybefore vaccination was rated “good” inonly 30% of samples. After vaccination,however, 100% of samples were rated“good.” • In another complex, only 33% ofsamples were rated good before vac-cine use, compared to 83% after vac-cination. (See Table 1.)• In contrast, one complex where thevaccine was not used, investigatorsrated only 25% of samples as “good”for diclazuril sensitivity at the start ofthe study. After continuing on a tradi-tional rotation program and “resting”diclazuril, 0% of the samples were rated“good” for diclazuril sensitivity.

Considering its 2-to 3-years’ experi-ence with coccidiosis vaccination andthe results of this trial, the poultry com-pany plans to continue using Coccivacand will carefully monitor results aswell as assess the vaccine’s role inlong-term methodology. “Many otherfactors are involved with the selectionprocess so we cannot say that theprocess is sensitivity driven, thoughthat’s a major factor,” says a veterinari-an for the company.

Take-home messagePointing to the good performance ofthe vaccinated flocks and the reductionin lesion scores, investigator Mathis

❝ …The take-home message is that to get the performance you got when you originally had diclazuril or other in-feed anticoccidials, you’re going to have to use a vaccine.❞

Mathis: ‘One of the most coccidiosis-significant studies’

continued on page 19

6

Identifying viable, sporulatedEimeria oocysts and ensuring thatbirds get just the right amount is

one of the most important steps that gointo producing an effective coccidiosisvaccine.

Even so, with thousandsof chicks moving throughthe hatchery, it’s difficult forbusy poultry veterinariansand production managersto appreciate the tech-nology, careful selectionprocess, experience andrigid quality-control stan-dards that need to go into avaccine of this nature.

“Coccidiosis vaccinationworks by providing a con-trolled, carefully balanceddose of oocysts — coccidialeggs — to protect againstthe several species ofEimeria that cause the dis-ease in birds,” says GrahamKnight, manager of coc-cidiosis vaccine production

at Schering-Plough AnimalHealth Corporation’s produc-

tion plant in Millsboro, Delaware. “It sounds easy, but there’s more to

it than gathering oocysts and puttingthem in a bottle. The preparation andidentification of suitable oocysts is cru-cial,” he says. “It’s also critical to havethe right balance of antigens, which arethe individual components that lead toprotection against the Eimeria speciescausing disease.”

Stimulating immunity Producers need to understand that for acoccidiosis vaccine to stimulate immu-nity, oocysts must be capable of releas-ing viable spores. “In other words, theymust be sporulated. They also must be

viable to be infective,” Knight says. “An infective oocyst is a sporulated

oocyst, but a sporulated oocyst is notnecessarily an infective one,” Knightsays. “We think this is an important dis-tinction for producers to know andunderstand.”

The reason is that sporulatedoocysts age and die. In addition, someoocysts never fully develop; they areonly partially sporulated, while othersmay be abnormal or damaged and arenot infective.

“A major part of our job is the iden-tification of fresh, fully sporulatedoocysts,” Knight says. “These are theoocysts that are infective and that con-vey immunity to birds against coccidio-sis. It takes a lot of experience to builda quality coccidiosis vaccine.”

Tried and trueAlthough it’s a tedious and importantprocess, identifying viable sporulatedoocysts isn’t rocket science, Knightinsists, but it does require an educatedeye.

“In Millsboro, we have well-trained,seasoned technicians — many havebeen involved since the operation wasmoved to Millsboro in the 1980s. With agood microscope, they can easily dif-ferentiate a fresh, fully sporulatedoocyst from an oocyst that’s not,” hesays.

Microscopic examination is the tra-ditional method of determiningwhether an oocyst is fully sporulatedand has been in use since the early1900s. “It’s a straightforward andproven method, one that requires nomanipulation of the sample other thandilution and needs no specializedequipment or technique,” Knightexplains.

Dr. Steve Fitz-Coy, now a technical

KNOW THE SPORE Identifying viable, sporulated oocysts key to a quality coccidiosis vaccine

COVER STORY

Knight: ‘It’s critical to have the right balance ofantigens…’

Photos by Lisa Helfert.

7

service representative for Schering-Plough Animal Health, agrees.

“Poultry producers have been deal-ing with coccidiosis for nearly 75 years,since groundbreaking work by E. E.Tyzzer in 1929. Identifying sporulatedoocysts with a microscope is a tried andtrue process that’s improved with time,”he says.

Knight points out that data collectedover the course of many years as wellas field experience have demonstratedthat coccidiosis vaccine made fromfresh, fully sporulated oocysts within afixed time frame has enough viableoocysts of each species at the end ofthe stated shelf-life (12 months) to beefficacious.

Complementary proceduresSeveral other procedures built into coc-cidiosis-vaccine production at Millsborocomplement the identification of viable,sporulated oocysts and contribute tothe vaccine’s efficacy, says Knight.

One is the way in which oocysts areproduced. Each coccidial species in thevaccine is grown in birds in a roomdedicated to that species. The roomsare located in an antigen-productionfacility. The birds are not used for mul-tiple species nor are they re-used, hesays.

“Although most species of coccidialoocysts can be differentiated by trainedtechnicians, there are exceptions.Different species have different sizesand shapes, but some overlap occurs,particularly among small oocysts.Growing each type in isolation solvesthis problem,” Knight says.

Technicians inoculate one group ofbirds with known and tested seeds ofone coccidial species. Excreted oocystsare then harvested and cleaned. “Wedon’t need to differentiate oocysts —we only have to determine whether anoocyst is fully sporulated or not andhow many there are.

“We need different numbers ofoocysts for each species to make

Coccivac. Ultimately, the oocysts areblended, but we grow them individual-ly,” he says.

Oocyst productionNevertheless, Fitz-Coy points out,oocysts excreted by birds are notsporulated when harvested and, there-fore, are not infective.

“We have to transform the harvest-ed, non-sporulated oocysts to thesporulated and infective form undercontrolled conditions by providingwarmth, humidity and oxygen,” hesays.

Adds Knight, “We mimic nature, butwith the benefit of controlled condi-

tions, we can efficiently transform themajority of oocysts over a given periodof time. Because the viability of sporu-lated oocysts decreases with time, theharvested material is processed quicklyat the Millsboro plant, which works tocGMP (current Good ManufacturingPractices).”

After sporulation, the antigen lot is

continued on page 20

Knight and Fitz-Coy: ‘We need differentnumbers of ooycsts for each species…’

8

The veterinarian was still skepti-cal. He wanted proof that vacci-nating broilers to prevent coc-

cidiosis wouldn’t hurt performance. His employer, a major poultry inte-

grator in the US processing millions ofbirds annually, hadn’t been vaccinatingagainst coccidiosis for long. Initially,there were some performance irregular-ities, but he couldn’t ignore the num-bers from the third cycle — the resultswere stellar.

A good study was needed, but com-paring a coccidiosis vaccine directly toa feed-grade anticoccidial programunder true field conditions would bedifficult. Non-medicated feed wouldhave to be provided to houses withvaccinated flocks; in particular, noanticoccidials could be fed to vaccinat-ed birds — they could destroy the vac-cine oocysts that help build immunityto coccidiosis.

Anticoccidial feed would have to bedelivered to other houses on the samefarms with unvaccinated birds. Carewould have to be taken to avoid man-ufacturing or delivery errors for the lifeof the flock. It would be a challenge fora big and busy integrator, but data wasneeded to determine whether changesshould be made to the standard coc-cidiosis control program.

Study designIn the fall of 2002, a multi-farm, paired-house trial was initiated. It involvedfour, 4-house farms raising heavy broil-ers (7.5 lbs). The integrator vaccinatedtwo houses on each farm withCoccivac-B, a live-oocyst vaccine; in theremaining houses, birds were fed ananticoccidial shuttle utilizing narasinand nicarbazin, which was the integra-tor’s standard program and served asthe study’s control. Evaluations wereconducted on 156,000 birds from thevaccinated group and on 156,000 birdsfrom the control group.

The ration formulation for the twotreatments was consistent except thatvaccinated birds received a virgini-amycin premix in the starter and finish-er ration and bacitracin methylene dis-alicylate and roxarsone in the growerration, while controls received narasin,nicarbazin and bacitracin methylenedisalicylate in the starter ration andnarasin and roxarsone in the growerand finisher rations (Table 1).

FindingsAt 4 weeks (28 days) and 7.5 weeks ofage (52 days), veterinarians fromSchering-Plough Animal Health andAlpharma Inc. conducted posting ses-sions on the 16 test houses, where theylooked for evidence of coccidial

COCCI CONFIDENTIAL

VACCINE CONTROLS COCCIDIOSIS, IMPROVES PERFORMANCE IN INTEGRATOR’S CONTROLLED STUDY

Editor’s note: The information for this article was provided by a major USpoultry company on the condition that its name and location be keptconfidential. The sources mentioned in the article have nevertheless

reviewed the information for technical accuracy and approved it for publication in CocciForum. It is presented here in our newest feature, Cocci

Confidential, to help the poultry industry learn from these real-world experiencesand improve their management of coccidiosis. If you have a story you would liketo share with Cocci Confidential, please contact the editor at JFeeks@prworks.netor call 508-627-6949 (US).

9

species. They used microscopic evalua-tion for Eimeria maxima, since thisspecies does not always produce dis-tinct gross lesions and is more likelythan other Eimeria species to impairfeed conversion and weight gain. By 51to 55 days of age, most of the lesionsreceived mild scores of +1 and +2(Figures 1 and 2).

In addition, the integrator processedbirds from each treatment separately.The processing plant reported standardperformance parameters such as thepercent livability, gross pounds sold,average weight, feed conversion andaverage daily gain (Table 2).

The results Vaccinated birds and the controlsreceiving feed-grade anticoccidials eachdemonstrated mild coccidial lesions at 4weeks of age. However, the lesions hadresolved by the second post-mortemexam at 7.5 weeks of age (Figures 1and 2). Vaccination did not appear toaffect either 7-day mortality or overalllivability compared to controls.

On a farm-by-farm basis, vaccinatedflocks outperformed or equaled theperformance of the control flocks for allsignificant parameters. Vaccinatedflocks also demonstrated better per-formance on an averaged basis.Compared to flocks receiving standardionophores, those that were vaccinatedhad: • An average weight 9.6 points higher• An average feed conversion 1.6

points lower• A caloric conversion 11 calories

lower• An adjusted caloric conversion 33

calories lower• A standard cost per pound 0.17

cents lower

Discussion & conclusionCoccivac delivers a controlled, bal-anced dose of sporulated or infectiveoocysts of the economically significantEimeria species. A new generation

of oocysts develop in vaccinated birdsand are then excreted, providing re-exposure to Eimeria oocysts. Theprocess stimulates natural, long-lastingimmunity.

Generally, it takes about two tothree oocyst cycles for strong immunityto develop. Vaccinated birds may bepresented with a field challenge from

Starter Grower Finisher

Coccivac-B virginiamycin 20g bacitracin virginiamycin 10gmethylene disalicylate 50g

Control narasin 62g nicarbazin 63g nicarbazin 54gbacitracin roxarsone 22g roxarsone 22gmethylenedisalicylate 50g

Table 1Ration Formulation: Coccivac-B vs. Control

E. acervulina E. maxima E. tenella

% B

irds

With

Les

ion

0

20

60

40

80

100Control Coccivac-B

Figure 1. Birds Age 51-55 Days

E. acervulina E. maxima E. tenella

% B

irds

With

Les

ion

0

20

60

40

80

100Control Coccivac-B

Figure 2. Birds Age 25-29 Days

continued on page 22

10

COCCI FAQs

Q. HOW PREVALENT ARE EIMERIAMAXIMA VARIANTS IN THE US, AND ISCOCCIVAC-B CROSS-PROTECTIVE?

A. Based on a recent survey of 33isolates of Eimeria maxima collectedfrom 11 states and 18 major poultryintegrators throughout the US, onlythree of the isolates (less than 10%)showed only partial protection by theCoccivac strain of E. maxima. In otherwords, the prevalence of E. maximaamong US poultry integrators that ishighly variant to the E. maxima inCoccivac is very low and is not ofmajor significance at this time.

The results of the study also indicatethat if birds are properly immunized,the vaccine strain of E. maxima inCoccivac-B would protect against awide range of field isolates encoun-tered in commercial operations in theUS.

Q. IS THERE ANY MERIT TO USINGAN AUTOGENOUS VACCINE FOR VARI-ANT SPECIES OF EIMERIA?

A. Autogenous vaccines are derivedfrom uncharacterized Eimeria fieldspecies. These poorly defined speciesare not subjected to the same rigoroustesting as the licensed, defined speciesof Coccivac. To develop a safe, consis-tent vaccine, it is imperative that thebasic species characteristics such aspathogenicity, antigenicity and anti-coccidial drug sensitivity are welldefined. Using a poorly defined vac-cine highly increases the risk of rapidlyspreading unwanted contaminates froma few selected farms to all companyfarms, which could be an overnight dis-

aster and a very expensive problem tocontrol later; it also decreases thechances of maximizing production per-formance due to inconsistent productmanufacturing from serial to serial.

Q. ARE YOU RE-ISOLATING THE VAC-CINE STRAINS FOLLOWING THE USE OFCOCCIVAC?

A. Yes. All research to date supportsour initial hypothesis that the vaccinestrains over 2 to 3 flocks are displacingwild field strains. This is evident by theEimeria population shift toward moresensitive strains as measured via anti-coccidial sensitivity testing (AST).

Q. HOW STABLE IS THE POPULATIONSHIFT TO EIMERIA STRAINS CONTAINEDIN THE VACCINE?

A. It is not a permanent change —it’s a shift. The vaccine strains becomepredominant in the absence of drugpressure. With drug pressure and time,the strains will shift back to those thatare drug tolerant/resistant.

Q. HOW MANY CYCLES OF COCCIVACUSE DOES IT TAKE BEFORE NOTICING ACHANGE IN THE EIMERIA POPULATION?

A. It’s difficult to say specificallyhow many, but the longer the removalof pressure from the drugs, the greaterthe chance of seeing a change in theEimeria population. We can say, how-ever, that there should be a minimumof two cycles and that three cycles arepreferred.

SCHERING-PLOUGH’S TECH SERVICE TEAM ANSWERS QUESTIONS ABOUT MANAGING COCCIDIOSIS IN BROILERS

Charles Broussard, DVM

Steve Fitz-Coy, PhD

Lanny Howell, DVM

John McCarty, DVM

Linnea Newman, DVM

Rick Phillips, DVM

John Radu, DVM

11

Q. WHAT ABOUT COMPETITIONBETWEEN THE WILD AND VACCINESTRAINS OF EIMERIA? WILL A SHORTLAYOUT TIME INFLUENCE THE OUT-COME?

A. Layout time will influence thedesiccation rate of Eimeria. Coccidiawill not be eliminated, but the longerthe layout period, the greater thereduction in numbers.

The advantage of vaccination is thatbirds are exposed early in life to vac-cine strains; eventually, they will devel-op immunity. Using a live vaccineallows us to control the dose (level ofexposure) as well as the timing (day-1)of exposure. These are two majoradvantages in controlling any diseaseprocess.

Q. DO COCCIDIOSIS VACCINESREQUIRE SPECIAL HANDLING?

A. Yes. Make sure the vaccines arenever frozen, which will kill or damagesporulated oocysts and ruin their effec-tiveness. If ice crystals are noticed inthe liquid, the vaccine should be dis-carded.

Store Coccivac vaccines at a temper-ature between 36°F to 47°F (2°C and8°C). The vaccines should be kept atthese temperatures during shipping aswell as during transport to farms orhatcheries. When the vaccines arerefrigerated, watch for uneven temper-atures that might allow partial freezing.

Q. ARE COCCIVAC VACCINES TESTEDFOR POTENCY?

A. Yes. Potency testing in live birdsis conducted on every serial (batch) ofCoccivac manufactured. Birds are vac-

cinated with the serial being tested andare then challenged with every speciesof Eimeria contained in the vaccine tomake sure they develop immunity. Ifthey have developed immunity, theydo not develop coccidiosis. The validi-ty of each potency test is checked bychallenging unvaccinated birds.

Q. DOES THE METHOD OF VACCINA-TION AFFECT THE AGE WHEN CHICKSCAN BE VACCINATED WITH COCCIVAC?

A. Yes. When the Spraycox spraycabinet is used, chicks can be vaccinat-ed in the hatchery because the sprayerenables uniform distribution; 21 ml ofcoarse spray is delivered for each boxof 100 chicks. Chicks “preen” to cleanand dry their feathers and ingest thevaccine. Red dye mixed in with thevaccine gets their attention and stimu-lates preening.

An alternative to using the Spraycoxapplicator is feed spray application. Itdoes not deliver the vaccine as uni-formly as the Spraycox applicator, butcan be used when hatchery applicationis not possible. Chicks must be 4 daysof age, however, since younger chicksmay not have developed uniform feedconsumption patterns.

Q. WHAT’S THE DUAL-NOZZLESPRAYCOX CABINET?

A. It enables simultaneous adminis-tration of Coccivac-B and Newcastle/Bronchitis (ND/IB) vaccines, which inturn provides producers with conven-ience and reduced labor costs. Thenozzle for Coccivac delivers the coc-cidiosis vaccine as droplets that areingested by preening. The nozzle forND/IB produces a flat, even sprayacross the box.

continued on page 21

12

TECHNICALLY SPEAKING

The hazards of poorly managedlitter are well known to poultryproducers. Too little moisture

can result in dehydration and respirato-ry illness. Too much moisture leads tolitter caking and ammonia, which caus-es a host of problems ranging fromblindness to poor flock uniformity.

Good litter management is essentialwhen it comes to managing coccidio-sis. Wet litter sets up an ideal environ-ment for the proliferation of coccidialoocysts, increasing the challenge tobirds and the risk for coccidiosis out-breaks.

In birds vaccinated against coccidio-sis, some exposure to coccidia is need-ed to stimulate immunity. If the litter istoo dry, there might not be enoughoocyst sporulation to stimulate immu-nity and make vaccination effective. Toadequately stimulate the coccidial lifecycle and immunity, a minimum of 25%litter moisture content is needed.

On the other hand, if the litter is toowet and oocyst sporulation is too high,birds could be overwhelmed with coc-cidial challenge before immunity isfully developed. Wet litter can set thestage for development of necrotic

enteritis (Clostridium spp.) since bacte-ria thrive in a moist environment.

ConsiderationsWhen devising a plan to control littermoisture, keep in mind that birds arecontinuously adding moisture to thehouse. As a general rule, birds drinkalmost two pounds of water (about onequart) for every pound of feed they eat.If 24,000 four-day-old birds eat approx-imately 1,000 lbs. of feed daily, theywill drink close to one ton of waterdaily. As birds get older, feed con-sumption increases dramatically — andso does the amount of water theydrink. By the end of a 7-week growout,a house with 24,000 birds has con-sumed over 100 tons of feed and wellover 200 tons of water! Where does itall go? Less than a third of ingestedwater is retained by the birds. The restis exhaled into the air in the form ofwater vapor or deposited into the litter.

When a grower operates exhaustfans, the moisture-laden air in thehouse is replaced with drier outside air,thereby removing water from thehouse. The drier air that the fans bringinto the house will not only pick upwater that the birds are placing into theair but also remove water from the lit-ter, keeping it drier. Of course, if a pro-ducer does not operate exhaust fansenough, water will build up in the airas well as litter leading to house sweat-ing and litter caking.

It’s all relativeWhen it comes to removing moisturefrom a house, it is important to knowthat the amount of water that air canhold varies dramatically depending ontemperature. The term humidity is usedto describe how much water is in theair. For instance, if the humidity is100%, we know the air is holding allthe water it can. If the humidity is 90%,

LITTER MANAGEMENTReview your program to minimize coccidiosis pressure and maximize control

Michael CzarickExtension EngineerUniversity of Georgia Athens

If litter is too dry, there may not be enough coccidia production to stimulateimmunity; litter that’s too wet can foster too much coccidia growth, overwhelm-ing birds before immunity is fully developed.

13

the air can only pick up a little waterfrom the litter and litter caking is morelikely to occur. If the humidity in ahouse is 40%, it is capable of pickingup a lot of water from the litter.

Because the amount of water the aircan hold changes with the temperature,relative humidity is a better term thanhumidity. For instance, 1,000 cubic feetof 40°F air can only hold less than eightounces of water, but 1,000 cubic feet of85°F air can hold about 32 ounces. At150°F, 1,000 cubic feet of air can holdan entire gallon of water. The fact thathot air can hold more water than coldair is why we use hot air when wewant to dry something off, such as wetclothes in a clothes dryer.

As a general rule, the moisture-hold-ing ability of air doubles for every 20degree rise in temperature. If 1,000cubic feet of 40°F air has 100% relativehumidity, it holds approximately 6ounces of water. If the temperature ofthat air is increased by 20 degrees, themoisture-holding ability of the air dou-bles and it can now hold about 12ounces of water. Since the air now hasonly half the water it’s capable of hold-ing, the relative humidity is 50%.

Let’s heat the same 1,000 cubic feetof air another 20 degrees to 80°F. Thereis still only less than 6 ounces of waterin the air, but now the air is capable ofholding about 24 ounces of water.Therefore, the air is only holding 25%of the water it can, and the relativehumidity is 25%.

So, can you dry a house when it iscold and rainy outside? Yes you can,because as you warm the air to theproper house temperature you areincreasing its moisture-holding abilityand the relative humidity of the airdecreases. Since the air can now holdmore water, it can remove more waterfrom the litter, keeping the house drier.

The key to drying cold wet air is tomake sure that all incoming air isbrought in through air inlets that directsthe air toward the ceiling. As the fresh

air moves along the ceiling, it is heatedby the hot air produced by the birdsand brooders/furnaces that tends tocollect at the ceiling due to the fact thathot air is lighter than cold air. Thelonger that incoming air can be kept atthe ceiling through maintaining theproper static pressure and inlet open-ing, the more the air will heat up anddry out. Maximum heating and dryingof air is obtained if the static pressureand inlet openings are set so that

incoming air stays at the ceiling until ithas reached the center of the house.

Circulation fansAnother way to promote litter moisturecontrol is through the use of small cir-culation fans that are 18 to 24 inches indiameter. Circulation fans can helpbring in drier air from the ceiling gen-tly down to floor level; water is pickedup from the litter, which keeps thehouse drier. Of course, if exhaust fansare not operated enough, moisture inthe air and litter can build up.

Circulation fans, if operated proper-ly, should not cause a draft at birdlevel. Generally, they should be con-trolled with an interval timer or variablespeed controller. Interval timer settings

Circulation fans can help maintain proper litter moisture, but shouldnot cause a draft at bird level.

14

or speed can be adjusted according tohouse conditions. If there is significanttemperature stratification or the litterneeds additional drying, timer settingsor the speed of fans can be increased.If the litter is very dry, the use of circu-lation fans can be decreased.

How much ventilation?To determine how much fresh air isneeded, use the chart (see Figure 1)that provides the required minimumventilation rate to get rid of moisture. Itis based on how much water the birdsare consuming, the inside house tem-perature and an average daily outsidetemperature of 40°F. The minimumventilation rates that are determinedfrom the chart should be viewed as astarting point that may need to beincreased or decreased according to a

variety of factors such as the type ofwaters used and how tightly the houseis constructed.

One of the best ways to figure out ifadjustments are needed to minimumventilation fan settings is to monitorrelative humidity in the poultry house.Ideally, relative humidity should bebetween 50% and 70%. If it is below50%, the litter may become too dry andminimum ventilation fan settingsshould be decreased. If the relativehumidity is above 70% for a prolongedperiod, litter caking and house sweat-ing can occur and minimum ventilationfans settings should be increased.

Practical examplesLet’s look at some examples of how tokeep litter dry based on what we’ve dis-cussed so far. Say a producer has olderbirds — which produce bigger, wetter

droppings and are kept in lower tem-peratures than younger birds — that thehouse temperature is 70° F and the rel-ative humidity is 65%. You start noticingthat the litter is getting a little damp andwant to dry it out before it slicks over.

First, you try turning down the timerfan thermostats to 65°F to bring in moreair. Since the air temperature is lower,the moisture-holding ability of the airdecreases, and the relative humiditywould increase to about 78%. This willmake it more difficult to remove waterfrom litter. Yes, you would bring inmore air, which would help to someextent, but the downside is that higherrelative humidity will make it more dif-ficult to pull out water from litter. Incontrast, let’s say we increase the housetemperature just 3° and leave the timerfan settings the same. The relativehumidity will decrease to approximate-ly 58%, making it significantly easier todraw water out of the litter.

Another option would be to leavethe house temperature the same andturn up the timer fan settings. Thiswould work provided we do not let thehouse temperature fall. In someinstances, this means adding heat to thehouse to maintain the desired housetemperature. The key to keeping ahouse dry is the quality, not quantity, ofair. Bringing in a lot of cold air and let-ting the house temperature fall usuallyis not as effective as bringing in a mod-erate amount of air and warming it up.

Contrary to common belief, usingwarm air to dry out litter does notalways mean increased heating costs.As outside temperatures increase dur-ing the day, the moisture-holding abili-ty of the air increases. Take advantageof that fact. During the day when thesun is out and the air temperature iswarmer, increase timer fan settings tocapitalize on relatively drier air.

Seasonal challengesCold weather is considered a time ofyear when controlling litter moisture is

❝ To adequately stimulate the coccidial life cycle and immunity, a minimum of 25%

litter moisture content is needed.❞

a big challenge, but hot weather canpresent problems too. Even thoughevaporative cooling pads and foggingnozzles can decrease air temperature ina house by 10° to 20°F, they can alsoraise the relative humidity of the air toabove 80%. Why? For every one degreeof cooling produced by an evaporativecooling system, the relative humidity ofair will increase by about 2.5%.Excessively high house humidity can beminimized by making sure that evapo-rative cooling pad/fogging systems areset to operate no lower than 82°F.

There’s one other important way

that excessive litter moisture can bekept to a minimum, and that’s by mak-ing sure that the evaporative coolingsystem does not operate after 10pm orbefore 9am in the morning. These aretimes when outside humidity typicallyis above 80%, which limits the amountof cooling to be produced by pads and/or fogging systems. When evaporativecooling systems are operated between10pm and 9am, they do little to cool theair and tend to saturate incoming airwith moisture, increasing the chance ofexcess litter moisture and all its inher-ent problems.

15

30

25

20

15

10

5

1 10 15 2050

Water Consumption (100 gallons per day)

Min

imum

Ven

tilat

ion

Rate

(Tho

usan

ds C

FM)

Minimum Ventilation Rates for Various Inside Temperatures(Inside Relative Humidity = 50%, Average Outside Conditions = 40°F, 50% Relative Humidity)

65°F

70°F

75°F

80°F

85°F

90°F

Figure 1

16

COCCI PROFILE

Coccidiosis is one of the mostsevere parasitical diseases ofbroilers and broiler breeders in

China, often presenting with severeclinical signs, including red blood in thefeces, poor flock uniformity and mor-tality.

The costly parasitic infection cancause subclinical disease, too, charac-terized by signs such as poor weightgain. Subclincal disease is more likelyto occur when other conditions, partic-ularly necrotic enteritis, are present.

“In the past, we mainly adoptedthree methods for control of coccidio-sis,” says Tai Youhua, DVM, director ofthe Animal Health Center for ZhuchengForeign Trade Broiler Co. Ltd, the sec-ond-largest broiler integrator in China’sShandong Province.

“First we managed the rearing style,such as rearing birds on net. Second,we rotated and shuttled the anticoccidi-als in feed. Third, we administered var-ious anticoccidial medicines, includingdiclazuril, or sulfa drugs,” he says.

“But none of these methods gener-ated the same efficacy as they hadbefore. Due to resistance, in-feed anti-coccidials such as ionophores and syn-thetic chemicals are no longer as effica-cious as they once were, and it wastime to adopt a new way of thinking incoccidiosis control by developingimmunity through vaccination,” Taiadds.

Medication problemsBesides resistance, he says, controllingcoccidiosis with medications raisesanother problem: Residues. Sulfa drugssuch as sulfaquinoxaline and sulfadimi-dine are highly efficacious in reducingmortality and controlling symptoms. Asa result, sulfa drugs are frequently theproduct of choice in China when coc-cidiosis breaks out due to their efficacyand cheaper price.

“But there are restrictions on sulfadrug residues in poultry to be exportedto Japan,” Tai says. “It is difficult for usto monitor the choice of anticoccidialby contract growers, so residues are abig concern for poultry meatexporters.”

In addition, there are restrictions onresidues in exported broiler meat formedicines including clopidol and nicar-bazine, which along with sulfaquinoxa-line have been banned by the Ministryof Agriculture of China. It is likely thatmore in-feed anticoccidials will bebanned in the future, he predicts.

The solution: vaccinationBecause resistance and residue wereserious concerns for export-orientedand “green” bird integrators, Zhuchengstarted vaccinating day-old chicks withCoccivac-B, which provides lifelongprotection against four leading species

YEAR OF THE VACCINEChina’s producers are shifting to biological controls to manage coccidiosis, avoid drug concerns

Veterinarians, nutritionists and producers in China fill room at recentmeeting to learn more about coccidiosis vaccination.

17

of Eimeria that affect broilers. The birdsare vaccinated in the hatchery with aspecially designed spray cabinet thatprovides uniform dosing.

The result, according to Tai, hasbeen good control of coccidiosis. Therehas been a significant reduction in theneed for treatment and subsequentconcern about residues. The vaccinealso has replaced field-resistant oocystswith highly sensitive vaccine oocysts,he says.

Vaccinating for coccidiosis, Tai con-tinues, also provides an excellentmethod of avoiding problems withresistance and residues. The oocystspecies used to produce the vaccinewere isolated before in-feed anticoc-cidials on the market were launchedand are therefore highly sensitive to allapproved ionophores and chemicaltreatments. That’s why replacing resist-ant field strains with oocysts in the vac-cine is beneficial, he says.

“Since the end of 2001, we havevaccinated about 25 million birds withCoccivac-B,” reports Wang Chunming,chief veterinarian of the Animal HealthCenter. “In fact, we mandated that allbirds reared on the floor must be vacci-nated at day of age by Coccivac-Bthrough spraying in the hatchery.

“Our growers have accepted theconcept of vaccination, especially sincethey saw the results obtained with thefirst 1.3 million birds either vaccinatedor medicated respectively,” he adds.

Those results showed that vaccinat-ed birds had an equal or better per-formance index than non-vaccinatedbirds. “As a result, growers no longeruse anticoccidials in feed for preven-tion or in drinking water for treatment,except for the occasional use ofdiclazuril to control mild post-vaccina-tion reactions. We are free of coccidio-sis and residues in broilers,” he says.

Technical service crucialBecause biological prevention againstcoccidiosis is a new concept for the

broiler industry in China, successfulimplementation of coccidiosis vaccina-tion required good technical service.

According to Tai, Schering-PloughAnimal Health’s technical personnelintroduced the advantages of coccidio-sis vaccination and created interest inCoccivac-B. They defined a trial proto-col based on local conditions withclients and taking into account the loca-tion, number of birds, groupings andmeasurement index. The team of spe-cialists also provided crucial support

Zhucheng hatchery workers use a specially designed spray cabinet to adminis-ter coccidiosis vaccine to day-old chicks.

Broilers vaccinated for coccidiosis have performed as well as or better thanmedicated birds.

continued on page 22

18

COCCI NEWS

EU Organic Trend More Perception Than Reality

Most poultry companies point to Europe when they thinkof the so-called trend toward producing organic and

free-range broilers, but that may be more perception thanreality, according to Isabelle Guillot, a veterinarian whoheads Schering-Plough Animal Health’s poultry business inGermany.

According to Guillot, organic and free-range birds makeup only 1.2% of the 461 million birds produced in Germany,Austria and Switzerland. “Organic product is difficult becauseof problems with the feed,” she says, “and the market isunlikely to increase past the present level of 0.8 millionbirds.”

Lack of consumer demand for free-range birds is anotherturnoff. One German company has stopped producing them,and at one site 50% of the production was being sold as con-ventional broilers.

“Only one company inGermany now produces free-range birds — and it representsonly 1% of their production,” shereports. “They’re also afraid topromote the product too muchbecause it might discredit theirconventional broiler products.”

Despite the shrinking marketfor free-range and organic birds,she says more mainstream oper-ations are still backing off in-feed anticoccidials and trendingtoward vaccination to avoid con-cerns over drug resistance andresidues.

Guillot: ‘Organic prod-uct is difficult because ofproblems with the feed.’

New TSB DetailsSensitivity Trial

Want more informa-tion on the anti-

coccidial sensitivity trialdescribed on page 4 ofthis issue? Schering-Plough Animal Healthhas published a newTechnical ServiceBulletin summariz-ing the key datafrom the study,complete withtables and colorcharts. For a free

copy, contact your companyrepresentative or send your request to Phyllis

Middleton. Email: phyllis.middleton@spcorp.com. Fax: 908-629-3206. Ask for publication SPAH-PBU-275 and rememberto include your full name and address.

More Support for Cocci Management

Schering-Plough AnimalHealth has realigned two US

sales territories and appointednew representatives to servicepoultry customers in key areas.

Paul Burke (paul.burke@spcorp.com) — a 10-year veter-an of the company’s PoultryBusiness Unit and the winner ofnumerous sales awards, includ-ing top sales representative in1994 and 2000 — will continueas a Senior Area Manager butwill be relocating to Texas toserve his new western territory,which also includes California,Oregon and Washington.Earlier in his career, Burke wasa grow-out manager for Cargill,Jacksonville, Fla., and attendedTexas A&M University, CollegeStation. He is currently based inGallatin, Tenn.

Burke is being replaced byRay Abner (ray.abner@spcorp.com) who recentlyjoined Schering-Plough AnimalHealth with more than 20 yearsof industry experience, includ-ing sales positions with Hoechst

Roussel Vet and Hoffmann-LaRoche. Abner has bachelor’s and master’s degrees in ani-mal science and nutrition from the University of Tennessee,Knoxville. Based in Lowndesboro, Ala., Abner will cover hishome state plus Indiana, Kentucky, Michigan, Ohio andTennessee.

Alarge US broiler integrator sought to

maximize the long-term efficacy of

Clinacox™ through rotation of the

diclazuril program with conventional

ionophore programs or with Coccivac®-B

vaccination.

Study Design

The integrator collected litter samples from

eight farms on each of seven complexes to

obtain baseline Clinacox sensitivity informa-

tion. Samples were submitted to Dr. Greg

Mathis, Southern Poultry Research, Athens,

Ga., for sensitivity testing. Prior to initial

sampling, the complexes had been on a vari-

ety of anticoccidial rotation programs, all of

which included Clinacox for one to two

cycles the previous year.

Dr. Mathis determined the Clinacox sensitiv-

ity based upon a combination of the per-

centage of weight reduction in test birds

compared to unchallenged controls and coc-

cidial lesion scores (Table 1, Figures 1 and

2). Then he summarized the efficacy of

Clinacox as “good,” “moderate” or “poor”

for each sample where oocysts were success-

fully isolated (Table 2, Figures 3 and 4).

Following collection of the initial litter sam-

ples, four of the seven complexes continued

their annual rotation using ionophores or

chemical-ionophore shuttle programs. The

remaining three of seven complexes incorpo-

rated two cycles of Coccivac-B vaccination

into the annual rotation.

The identical houses were re-sampled after

two cycles of Coccivac-B or anticoccidial

rotation.

Results

Complexes that continued to use a non-

Clinacox anticoccidial rotation showed little

or no improvement in Clinacox sensitivity

following the additional “rest” period.

Complexes that used two cycles of Coccivac-

B in the rotation showed significant

improvement in Clinacox sensitivity. None

of the samples scored “poor” following

Coccivac-B use, and all categories demon-

strated consistent improvement.

S C H E R I N G - P L O U G H A N I M A L H E A L T H

Clinacox™ Sensitivity of Field Eimeria Isolates Sig

nificantly

Improves Following Vaccin

ation with Coccivac®-B

t e c h n i c a l s e r v i c e s b u l l e t i n

■ A large US broiler integrator investigated

the impact of rotation programs on the

sensitivity of field Eimeria spp. samples to

Clinacox™ (diclazuril).

■ Resting Clinacox by rotating it with

ionophores or chemical/ionophore shuttle

programs produced neither consistent

nor significant results.

■ Two cycles of Coccivac®-B in the rotation

resulted in dramatic improvement in

Clinacox sensitivity.

275

Key Points

Paul Burke

Ray Abner

Got a Story Idea for CocciForum?The editors of CocciForum welcome news tips and

story ideas from its readers around the world. If

there’s a particular subject you’d like to see covered

in a future issue — perhaps a specific area of cocci-

diosis management — please let us know. Write to

JFeeks@prworks.net or call 508-627-6949 (US). We

want to hear from you.

19

notes that two cycles of Coccivac-Bprompted a dramatic shift towardincreased diclazuril sensitivity.

“We followed exactly the samehouses before and after diclazuril wasused, then used Coccivac so we could

pinpoint for sure whether we werereplacing resistance,” he says. “Theresults demonstrate that we can replaceor at the very least dilute the amount ofEimeria resistance that’s out there byusing Coccivac for several cycles andmaking it part of a long-term controlprogram.”

Mathis, who calls the landmark trial“one of the most coccidiosis-significantstudies” he’s worked on in more than20 years, thinks the results will go along way toward directing coccidiosismanagement in the future.

“The take-home message is that toget the performance you got when youoriginally had diclazuril or other in-feedanticoccidials, you’re going to have touse a vaccine. Coccivac is the only coc-cidiosis vaccine that has clearly demon-strated that it can replace resistance.”

Phillips agrees and says the resultsare almost an exact duplication of past

Phillips: ‘These are powerful findings thatcould revolutionize the way the industrycontrols coccidiosis for years to come.’

Clinacox Sensitivity (%)

Complex Rotation Program Good Moderate Poor

A - Before Anticoccidial 25 12.5 62.5After Anticoccidial 0 12.5 87.5

B - Before Anticoccidial 25 12.5 62.5After Anticoccidial 16.7 33.3 50

C - Before Anticoccidial 16.6 0 83.3After Anticoccidial 0 50 50

D - Before Anticoccidial 0 80 20After Anticoccidial 20 40 40

E - Before Anticoccidial 25 50 25After Coccivac-B 57 42.8 0

F - Before Anticoccidial 33.3 0 66.6After Coccivac-B 83.2 16.6 0

G - Before Anticoccidial 30 30 40After Coccivac-B 100 0 0

Table 1The Results of Sensitivity Testing at the Seven Complexes in the Study

Irrefutable Evidence continued from page 5

20

pen study trial results. “These are pow-erful findings that could revolutionizethe way the industry controls coccidio-sis for years to come,” he adds.

“For the first time in decades, vacci-nation is being viewed as a foundationto successful coccidiosis management— one that can be used either year-round or in a carefully planned, long-term rotation with in-feed anticoccidialsto maximize their impact.”

Poor Moderate Good

Complex E Complex F Complex GBefore After Before After Before After

Perc

ent

0

20

40

60

80

100

Figure 1. Rotation withCoccivac-B for two cyclesdramatically improved sen-sitivity of field isolates toClincox.

sampled and technicians identify andcount the number of infective oocystsper ml. “We get at least two independ-ent counts on freshly produced materi-al using light microscopy,” Knight says.

The final product includes non-sporulated and partially sporulatedoocysts, but only oocysts that are fullysporulated are counted as infective, hesays.

Fitz-Coy says, “We must keep inmind that oocyst viability decreasesover time. Not all originally countedinfective oocysts will be viable by theexpiration date on the vaccine.”

Consequently, the Millsboro teammakes sure that every vaccine formula-tion contains sufficient infective oocyststo allow for the decay of some infectivelive oocysts. “That way, the vaccinemaintains potency through its statedshelf-life,” he says.

Antigen production is completeonce the harvest has been treated witha chemical sterilant and quality controlhas released the lot on sterility, purityand titer, he says.

Potency testingTo be absolutely certain every final vac-cine serial (a blend of individual vac-

cine lots) is efficacious, techniciansconduct potency testing in live birds,says Knight. “Vaccinated birds are chal-lenged with each Eimeria line to makesure immunity has developed.Unvaccinated control birds also arechallenged to ensure the validity of thetest.”

Besides making sure that everybatch of vaccine contains enoughviable, sporulated oocysts, the countalso ensures that birds aren’t exposedto too many, which could cause astronger than needed immuneresponse.

“Actually, the formulation ensuresthat fresh vaccine is not too potent,”says Knight, “but as an extra precau-tion, we conduct safety tests in birds atan increased dose level.

“The nature of the potency testmakes it both time- and resource-con-suming. It also eats into the availableexpiration dating of the product.However, we still believe that a chal-lenge potency test is the best way todemonstrate vaccine efficacy,” he says.

Additional testingEvery batch of Coccivac also is testedfor the presence of extraneous viable

Know the Spore continued from page 7

21

Have more questions about coccidiosis vaccination? Send yours to the editor atJFeeks@prworks.net or by fax to 928-569-2491. You’ll get a personal reply from a Schering-Plough Animal Health Corporation technical service representative and we may include it in our next issue of CocciForum.

Q. HOW DOES STOCKING DENSITYAFFECT COCCIVAC VACCINATION?

A. You’ll get more uniform results ifthe initial stocking density is 0.75 ft2 to1.0 ft2 per bird. Higher stocking densitycould result in excessive litter moistureand a high litter oocyst density.

After vaccination, third-house andhalf-house brooding encourages prop-er Coccivac cycling for the first 7 to 14days. Remember that for full immunityto develop, birds require not only theinitial “dose” of live sporulated oocystsadministered via the vaccine, but twoor more life cycles of coccidia.

Q. WHAT’S THE BEST LITTER MOIS-TURE CONTENT FOR BIRDS THATRECEIVE COCCIVAC?

A. A minimum litter moisture contentof about 25% is needed to stimulate thecoccidial life cycle, but too much mois-ture will lead to poor Coccivac results.If the litter is too wet, coccidial cyclingmay be heavy, causing too much reac-

tion in birds and even overgrowth ofthe bacteria that causes necrotic enteri-tis. Too much litter moisture also canlead to transient immunosuppressiondue to “cold stress” as well as highammonia, resulting in blindness andpoor flock uniformity.

Q. WHAT TIPS DO YOU HAVE FORGOOD MANAGEMENT OF LITTER MOIS-TURE?

A. One way to reduce litter moistureis by properly maintaining nippledrinkers, which reduce the amount ofwater spilled into the litter. Consideryour ration formulation. Some rationsreduce the amount of excreted mois-ture. Litter type and depth shouldaccommodate the amount of moistureexpected in the house. Ventilation alsocan be adjusted to control litter mois-ture. Bird density needs to be con-trolled to avoid the moisture concentra-tion.

For more information on managing littermoisture, see the article by Mike Czarickon page 12.

Cocci FAQs continued from page 11

bacteria and fungi, according to USDAregulations and, for added measure, formycoplasma even though this testing isnot a government requirement.“Although the potency test is criticalbecause it demonstrates that all speciesare present in sufficient numbers to ini-tiate the immunizing process, thatalone is not enough to warrant releaseof the vaccine,” he says. Further testingis carried out to demonstrate freedom

from contaminating viral agents.The effectiveness of Coccivac is

ensured by a range of measures startingwith the quality of raw materials andending with shipment of the product,according to Knight.

“Every single stage of production,be it a quality-control test, an in-process check, an incubation tempera-ture or storage time, is documentedand reviewed for compliance prior to

22

previous flocks before their immunity isfully established, which explains whyperformance results may seem irregularwith the first cycle of Coccivac-B.

In this rare multi-farm, paired-housestudy, Coccivac-B was successfullyused for the long-term management of

coccidiosis without sacrificing perform-ance. In other words, Coccivac-B usedin real-world conditions not only con-trolled coccidiosis, it improved broilerperformance compared to ionophoreanticoccidials.

Treatment Age No. % Gross Average Feed Cal Cal conv ADG Cost(days) started Liv lbs sold weight conv conv adj 7.5lb per lb

Coccivac-B: 59.8 156,600 97.33 1,161,909 7.623 2.096 3022 2994 0.128 .2088Total orAverage

Anticoccidial: 59.8 156,600 97.47 1,148,824 7.527 2.112 3033 3027 0.126 .2105Total orAverage

Coccivac-B N/A N/A -0.14 13,085 0.096 -0.016 -11 -33 .002 -.0017Advantages

Table 2Summary of Performance: Coccivac-B vs. Control

during the trial, including on-site visitsat 7, 14 and 21 days post-vaccination.The trial enabled customers to realizethe advantage of Coccivac-B andhelped Schering-Plough Animal Healthlearn how to adapt Coccivac-B to localconditions.

“We have about 2,500 growers,”adds Wang. “It is very difficult for us toteach all growers about using Coccivac-B in a short time.”

As a result, Schering-Plough AnimalHealth’s technical staff in China provid-ed training to most of the growers,which are located in 75 villages withina 200 km radius. In addition, the com-pany provided a concise and easilyunderstood post-vaccination manage-ment list, which included informationon feed, litter, moisture, necrotic enteri-

tis and vaccination reaction control, hesays.

The training, coupled with post-vac-cination on-site visits and managementtips, enabled growers to develop ade-quate skills and knowledge aboutCoccivac-B. “That eventually solved theproblems of resistance and residues —both issues that perplexed our businessbefore,” Wang says.

Schering-Plough Animal Health’stechnical service specialist David Xuanagrees, adding, “The success ofCoccivac-B depends on post-vaccina-tion management, which must be customized to the local situation.Coccivac-B can become the best choicefor coccidiosis control if a concrete and practical technical service plan isprovided.”

Cocci Confidential continued from page 9

Coccidiosis Vaccination in China continued from page 17

23

CocciForum is published by the Worldwide Poultry Business Unit ofSchering-Plough Animal Health Corporation, Union, NJ. The editors welcome your ideas and suggestions for news articles concerning coccidiosis management. Send correspondence to CocciForum, Feeks Communications, PMB 239, Edgartown, MA 02539-9000, USA. Efax 928-569-2491, E-mail JFeeks@prworks.net.

© Copyright 2003, Schering-Plough Animal Health Corporation. Articlesmay be reprinted for educational purposes with written permission from the publisher.

Executive Editors: David Kelly Fabio Paganini

Managing Editor: Joseph Feeks

Design & Production: Deborah Sottile

Contributing Writer: Diana Delmar

Technical Advisor: Rick Phillips

COCCI VIEWS

These days, as we head intoanother US presidential elec-tion year, it seems everyone— politicians, talk-showhosts, newspaper columnistsand even the kid at the videostore — has an opinion or

theory about how to fix the problems of the world. It’sgood to see people thinking and sharing their views. Butas we all know from experience, it’s one thing to presentan idea. Making it work is entirely another.

Now I’m smart enough to realize that managing coc-cidiosis in poultry is a long way from balancing the budg-et, creating more jobs or bringing us lasting peace andsecurity. Nevertheless, a recent experience I had evaluat-ing long-term options for coccidiosis control underscoredthe value of presenting new ideas, putting them to thetest and making them work in the real world.

Two years ago, Schering-Plough Animal Healthlaunched Clinacox (diclazuril), a new-generation synthet-ic anticoccidial that was shown to be highly effectiveagainst the many wild and resistant strains of Eimeria inthe field. Birds medicated with Clinacox also showed sig-nificant improvements in feed conversion — often a 5-point1 boost — while also yielding significant gains inenergy efficiency.

Knowing that all in-feed anticoccidials can lose somepunch with continuous usage, we strongly urged thepoultry industry to use Clinacox judiciously — either forone cycle annually or in a shuttle program (starter orgrower ration, but not both) in two sequential cycles.

Because Clinacox cleaned up the resistant Eimeriapopulations, we then recommended rotating to the live-oocyst vaccine, Coccivac-B, and using it two to threecycles. The theory was that Coccivac could start from aclean slate while also seeding houses with older, highlysusceptible strains of Eimeria. This practice had alreadybeen proven with ionophores, but the jury was still out

when it came to using Coccivac in a program withClinacox. As Dr. Rick Phillips puts it in the trial report onpage 4: “Despite the research and all the field reports inhand, we felt it was important to test our hypothesis inthe field where the proverbial ‘rubber meets the road’.”

So that’s just what we did. We took a theory or a goodidea, put it to the test in real-world conditions andshowed how these two important tools — Clinacox andCoccivac — could be used to develop a long-term, inte-grated approach to coccidiosis management. It’s gratify-ing to read that one of the independent cooperators inthe study, Greg Mathis, PhD, of Southern PoultryResearch in Athens, Georgia, called the landmark trial“one of the most coccidiosis-significant studies” he’sworked on in more than 20 years.

This latest field trial is, of course, another good exam-ple of the commitment that Schering-Plough AnimalHealth has made to the worldwide poultry industry. We’llcontinue to bring this expertise and sound science to thefield through articles in CocciForum, as well as throughpresentations at industry meetings and our new series ofTechnical Service Bulletins. We can’t do it alone, howev-er. As I said before, it seems everyone has an opinionabout how to fix the problems of the world, includingcoccidiosis in poultry. We hope that you’ll continue shar-ing yours with us.

,

Worldwide Technical ServicesSchering-Plough Animal Healthcharles.broussard@spcorp.com

1 0.05 improvement in pound of feed per pound of live weight gainduring the period of the first treatment. Data on file at Schering-Plough Animal Health Corporation.

Putting Ideas to the Test

High Performance Strategy • www.spah.com

PerformanceCoccivac®-BCoccivac®-BDesigned for peak performance against coccidiosis

• Proven protection against coccidiosis

• Critical component of coccidiosis control strategy• Efficient and efficacious administration via

Spraycox™ cabinet• Service and expertise of our skilled veterinary

staff and sales force

Coccivac®-B is a registered trademark of Schering-Plough Veterinary Corporation.Copyright 2003, Schering-Plough Animal Health Corporation. All rights reserved.