COOPERATIVE EXTENSION UNIVERSITY OF CALIFORNIA

CaliforniaPoultry Letter

FEBRUARY 1991

A FOOD EDITOR'S THOUGHTS ON THE SALMONELLA ISSUE

Karyn I. Lipman is a Staff Editor withSunset Magazine. Karyn's formaltraining is in Food Science and

Technology, and she has a B.S. in that

discipline from the University ofCalifornia, Davis (1987). While an

undergraduate, Karyn took advantage ofinternship programs and spent thesummer of 1986 working with Santa Rosa

Egg Farms.

This past December, Karyn participatedin our Poultry Symposium. Thefollowing are some of her thoughtson Salmonella enteritidis and the

advice she passes on to her readers.

Some publications or editors havewritten warnings about eggs or bannedtheir use. Sunset Magazine did theirown in-house testing (temperature andpH) and found that — consumers needto revise methods of cooking with eggs-- not eliminate egg use.

Sunset assumes their readers can

maneuver a quick-read thermometer tocheck internal temperatures, andlitmus paper to monitor pH. UnlikeUSDA and FDA, Sunset does not have to

advise the general population; our

guidelines are more moderate and (webelieve) more reasonable.

Eggs have taken a few hard cracks. Unscrambling the solution.

There has been an increase in out¬

breaks nationwide but the risk of

illness from Salmonella by con¬

taminated eggs in the state ofCalifornia is extremely small. SE iseverywhere—on pets, in the soil, on

your hands. It's very rarely in theegg.

Research indicates that less than 15

percent of outbreaks occur in thehome. Evaluate the restaurants where

you eat out. Do they handle eggs

properly?

A. Fail safe method: simply, cookeggs thoroughly and/or eat well-cooked eggs. Thorough cookingkills SE.

B. Or with thought and observation,control SE's presence and growth.

-Wash your hands, work area and

equipment thoroughly and often.

-Buy only fresh, refrigeratedeggs. Don't let them sit out at

room temperature for longer than

The Urxversity ot CaMotma. m oon*)tiance with the Cwl Rights Act o11964. Ti«e IX ol the Educator Amendments <4 1972. and the Rehab* tat ion Act ol 1973. does not drscrtmnate onthe bass ol race, creed, religion, color. natxxtal ongn. sex. or mental or physical handcap «i any ol as programs or actuates, or witn respect to any ol its employment potcres. pracaces.or procedures. The University ol CaMonxa does not dBcrirrenate on ate bass ol age. ancestry, sen*! onemaiion. marital status, citizenship, medical condition (as deified in section 12926ol the CaMornia Government Code), nor because ndwluah are disabled or Vetnam era veterans Inqunes regardng pits potcy may be directed to the Director. Oltice ol Alternative

Action. Divisor oI Agriculture and Natural Resources. 300 lafcesxte CXrve. Oakland. CaMoma 94612 3550. (415) 967-0097

Issued in furtherance oI Cooperative Extensor work. Acts ol May 6 and June 30.1914. *i cooperaaon with the U.S. Department oI Agriculture. Kennetn R. Farrea.Ovector oI CooperativeExtensor, University o> Caalomia

2 hours. Are the stores where

you purchase eggs and therestaurants that you patronizeproperly handling eggs?

-Arm yourself with an accuratequick-read thermometer. Checkits accuracy in boiling water(212 degrees). Observe tempera¬ture changes with changes inaltitude. For quicker temp¬erature reading, preheat thermo¬meter by placing in warm water.

-Have on hand litmus paper (inthe range of 0 to 6) fordetermining pH. Litmus paper isavailable at scientific supplystores.

-Know how to cook eggs to SE safetemperatures (greater than 140degrees), serve foods withlightly cooked eggs quickly, andstore/chill eggs and egg dishespromptly.

-Be certain to cook or reheat

products containing eggs

thoroughly i.e., lasagne, andcasseroles. Don't consume raw

cake and cookie batters.

Think about who you're feeding.

Those at risk:

-elderly

-pregnant woman

-the very young

-those with compromised immunesystems OR on medications whichalter the immune system or

antibiotics.

-Even someone who takes antacidscan have a reduced ability to

fight off SE.

-Double sanitize eggs. Firstwash hands then immerse eggs inboiling water to cover. Liftout, then proceed.

-Follow Sunset Magazine's in¬structions to modify recipes.The article will be published inthe Spring.

-Consumers need to watch for

surprising new food vehicles forSE: pasteurized cheese products,or fruit from Mexico packed inice.

MOST IMPORTANTLY, CONTROL TEMPERATUREAND pH.

Karyn I. Lipman, Staff EditorSunset Magazine

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The Nation's Restaurant Menus

The National Restaurant Association

(Food Institute Report, December 22,1990), recently reported the top tenmenu features in the United States.

For its report the Associationcompared 1985 and 1990 menus. The

biggest difference (22 share pointchange) was in the percent of menus

featuring light and healthy sections.The section jumped from 12 to 34%between 1985 and 1990. This increase

bodes well for the poultry industry,as chicken and turkey are frequentlyincluded in the "healthy entree"categories.

2

VENTILATION AND TOXIC GASES

There are several hazardous gasesassociated with poultry productionthat have a subsequent effect on pro¬duction. The confinement of animalsin closed structures increases the

potential of gas toxicosis.

The two main toxic gases frequentlyencountered in poultry production areammonia (from the decomposition ofuric acid and feces) and carbonmonoxide (from the inefficientcombustion of fuel burning heaters).When these air pollutants are producedoutdoors, they diffuse out as thebreezes dilute them. However, whenproduced indoors, they accumulate, andtheir dissipation and dilution dependsdirectly on the ventilation system inthe building. Fortunately, even atrelatively low ventilation rates usedduring cold weather, ammonia usuallyremains below toxic levels. However,accidents, poor building design, andimproper operation may result ininsufficient ventilation and thus, theconcentration of these gases maybecome higher. It is important torecognize the occurrence of these twogases and hence, prevent future gastoxicosis outbreaks from occurring.

Ammonia is produced from thedecomposition of poultry waste.Humans can detect it at levels of 10

ppm or less. Levels in enclosedpoultry facilities usually remainbelow 30 ppm. However, it can reachlevels of 50 ppm or higher during longperiods of operation. Since ammoniais highly soluble in water, it willreact with the moist membranes of the

eye and respiratory system. Some ofthe signs of ammonia toxicosis includeexcessive tearing, shallow breathing,and clear or purulent nasal discharge.Even at levels between 25-100 ppm,ammonia acts as a chronic stressor.

Look for birds with their eyes closedmost of the time, listlessness, andreduced feed intake. High levelscause eye opacities and tracheitis.Diagnosis is based on history andfield observation as laboratoryanalysis will be of limited value ininhalation exposure cases.

The other gas is carbon monoxide. Atcertain periods in the production ofpoultry, such as the brooding ofchickens or turkeys, the demands forheat are high but the need forventilation is minimal. Thus, ifmanagement is careless, theventilation will be so closed thatthere is insufficient oxygen for theburners and hence, substantialquantities of carbon monoxide ratherthan carbon dioxide are produced.Also, if the maintenance of burnersare neglected, deposits of dust buildup around the air inlets to theburners and starve the oxygen supply.Normal levels are from 0 to 5 ppm.Harmful effects are seen at 50 ppm.Low exposure levels result in list¬lessness, disorientation, uncoordina-tion, and difficult breathing. Highexposure levels result in rapid death.This condition is suspected when thehistory suggests exposure to unventedfuel burning heaters and clinicalsigns of acute death or difficultybreathing. Exposure to high levels ofcarbon monoxide can be confirmed with

a blood analysis for carboxyhemoglobinlevels. The blood will remain stable

for several days if refrigerated.

Thus, maintaining adequate ventilationis of utmost importance to preventthese two gas toxicosis fromoccurring. To prevent carbon monoxidetoxicosis, maintain brooders/heatersin optimal working condition. For theprevention of ammonia toxicosis,ventilation and waste management are

necessary. Moreover, although thereare numerous fatalities recorded due

to gas intoxication, the most costlydamage to the producer is the role ofthe gas as a chronic stressor.Chronic stress reduces feed consump¬tion, lowers the growth rate, andincreases the animals susceptibilityto other pathogenic microorganisms.All this leads to a decreased pro¬duction. So, ventilate!

Dr. Teresa Morishlta

Avian Medicine Resident, U.C. Davis

3

SALMONELLA PULLORUM—STILL AROUND AFTER 55 YEARS OF ERADICATION

S. pullorum, an egg-transmitted bac¬terial infection has the ability todevastate a poultry industry. Tocontrol the organism in the U.S., theNational Poultry Improvement Plan(NPIP), a voluntary scheme for poultrybreeders administered by stateagencies cooperating with the U.S.Department of Agriculture, was begunin 1935. With the conscientious in¬

dustry utilization of the scheme andadditional control measures instigatedby individual breeders, there wasvirtual disappearance of S. pullorumfrom commercial poultry by the early1970's.

However, the organism did notdisappear from all poultry. In theyears 1981-90, the National VeterinaryServices Laboratory identified morethan 500 positives from many parts ofthe U.S. Nearly all of those werefrom chickens, but other birdsincluded chukar partridges, guineafowl and parrots. Most of theisolates were from mature birds insmall individual flocks. Sometimes,however, infection did spread and veryoccasionally commercial flocks wereinvolved. In 1989 one outbreak in a

small breeding flock led to 73 otherisolations in several states. In 1983

a single large commercial broilercomplex became infected from an

unknown source and, in 1984, pullorumreoccurred on the same premises. In1990 S. pullorum was found to be well-established in a large integratedbroiler/roaster operation. The mostsignificant external lesions in thebirds were swellings of the joints("blister birds") with a purulentarthritis. Economic factors included8% higher mortality, 0.5% highercondemnations and resulting in anextra cost of 1.5 cents/lb.liveweight, plus many hours of blood-testing (150 breeder houses), anddifficulty in disposing of infected

material. Eggs and hatchery residueswere buried, and infected breedersrendered. There has been no spread to

any other company, and to date noevidence of how the organism got intothe breeders.

Strict biosecurity and conscientiousblood-testing is the best protectionagainst this organism. Remember thatmany birds in addition to poultry cancarry it. Watch out for unusualdisease symptoms in flocks and use

your diagnostic laboratory.

Note: In 1990, S. pullorum wasisolated from a backyard flock inScotland (which has also operated aneradication scheme for many years),the first isolation there in ten

years. This organism is a realsurvivor and will probably be aroundin the U.S. and other countries for

many years.

Dr. Duncan McMartin

Extension Veterinarian, U.C. Davis

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LAMP CONVERSION REBATES

This newsletter has recently containeda Fact Sheet on lighting which hassuggested that compact fluorescentlamps or tube fluorescent lamps beused to replace incandescent lamps inlaying houses. Richard Best,Agricultural Power Engineer with PG&Ehas indicated that customers who

purchase electricity from PG&Eprobably can qualify for rebatesassociated with energy conservation.Under this program the company rebatesa portion of the initial cost of

relamping poultry houses or otheragricultural buildings and for someother energy conserving changes suchas energy efficient motors. Contactthe company for details.

4

UPDATE ON AVIAN EMBRYO VACCINATION

Dr. Patricia Wakenell is the most

recent addition to the Department ofEpidemiology and Preventive Medicineat the University of California,Davis. All her degree work (B.S.,D.V.M., and Ph.D.) was completed atMichigan State University, EastLansing. In addition, she is a

board certified veterinary clinicalpathologist.

The following is a presentation Dr.Wakenell made at our recent PoultrySymposium.

Initially, embryo vaccination was

explored as an alternative to con¬ventional vaccination in order to

provide earlier immunity forselected diseases while simultane¬

ously reducing manual labor requiredfor conventional vaccination.

Development of an embryo vaccinerequires extensive research. Fol¬lowing is an example of a typicalprocess for developing an embryovaccine using Infectious BronchitisVirus (IBV) as an example.

Embryos were vaccinated on theeighteenth day of embryonationagainst IBV. A commercial vaccineof Massachusetts 41 strain IBV was

found to be highly pathogenic forembryos necessitating passage inchick kidney tissue culture in orderto reduce pathogenicity. The virusbecame apathogenic for embryos atthe 40th tissue culture passagelevel (P^q-IBV). Maternal antibody-positive or -negative chickshatching from eggs injected withP^g-IBV developed antibody againstIBV as determined by a constant-virus diluting-serum plaquereduction assay. When challenged at4 weeks of age with virulent IBV (C-IBV), these chicks were protectedboth from clinical symptoms of IBVinfection and isolation of C-IBVfrom the trachea. While P^g-IBVprotected chicks when administered

on ED18, this virus did not protectwell if given at hatch.

In addition to developing the embryovaccination for IBV, the effects ofthe vaccine on the embryo's immunesystem were extensively investi¬gated. Embryos and chicks wereexamined for lesions caused by thevaccine both grossly and by lightand electron microscopy. When theP^q-IBV embryo vaccine was combinedwith turkey herpesvirus (HVT), therewas no interference with the pro¬tection against challenge withvirulent Marek's disease virus, nor

did the presence of HVT interferewith the protection against C-IBVchallenge afforded by P^g-IBV.Thus, under laboratory conditions,P^q-IBV was an effective embryovaccine against IBV that could becombined with HVT as a bivalent

vaccine.

Recently, Embrex, Inc. has developeda machine that is capable of safelyand effectively vaccinating 10,000or more embryos an hour in a fieldsetting. Concurrently, Sanofi AnimalHealth's HVT vaccine was licensed

for use in ovo by the USDA. Sincelicensure, one machine has beenlocated at a major commercialhatchery and has been usedextensively for HVT vaccination. Upto six new machines are expected tobe in use commercially by year end1991. In addition, Sanofi AnimalHealth's SB-1 vaccine has just beenlicensed for use in ovo in

combination with HVT.

Therefore, embryo vaccination ap¬

pears to be a practical and economi¬cally advantageous alternative toconventional vaccination for poultrydiseases.

Patricia S. Wakenell, DVM

Epidemiology & Preventive Medicine

5

NEW PUBLICATION

A new publication Labor ManagementLaws in California Agriculturepublication No. 21404 has beenreleased by UC. This is a majorrevision of "Laws Affecting FarmEmployment in California (1985)".It summarizes federal and state

policy regulating agricultural labormanagement. The publication focuseson laws that either set limits on

specific terms of employment or elseguide collective bargaining betweenproviders and users of labor. Thepublication costs $10.00 and can beordered from ANR Publications, 6701San Pablo Avenue, Oakland, CA94608-1239.

******************

RE-EVALUATION OF CALCIUM, PHOSPHORUSAND VITAMIN D FOR EGG SHELL QUALITY

Dr. K. Keshavarz, Cornell Univer¬sity, Department of Poultry andAvian Science, has recently com¬

pleted a study of egg shell qualityas it is related to diet. His studylooked at the following variables:

1. Calcium levels of 3.5%, 4.0%,4.5%, 5.0%, and 5.5% with .4%available phosphorus.

2. Step-up calcium (3.5%, 4.5%,5.5%) with constant .4% availablephosporus.

3. Step-down phosphorus (.4%, .3%,and .2%) with 3.5% calcium.

4. Step-up calcium and step-downphosphorus as 2 and 3 above.

5. Same as 4, but half of thecalcium from oyster shell.

6. Same as 5, but with vitamin D^step-up (lx, 2x, 4x).

All of these dietary programs werefed from 20 to 64 weeks of age.Phase feeding programs were from 20to 36 weeks, 36 to 52 weeks or 52 to64 weeks of age, respectively.

Increasing calcium, decreasingphosphorus, increasing vitamin D^ orcombinations of these did not

improve egg shell quality. However,replacing half of the calcium withoyster shell improved egg shellquality even when the higher levelsof calcium were used. None of these

dietary changes affected eggproduction. These results tend tosubstantiate the present NRCrequirement of 3.75% calcium forlaying hens. They also suggest thatoyster shell may be of benefit whenshell quality problems areencountered.

Ralph A. ErnstExtension Poultry Specialist

******************

SE DRAG SWAB KIT AVAILABLE

Materials for on ranch sampling ofpoultry houses have been developedby Dr. Mallinson at the Universityof Maryland in cooperation withUSDA. At the ranch the sampling isdone with a drag swab. The swabscan be stored for several days in aspecial transport media. Environ¬mental Systems Service, Inc. P.O.Box 520, Culpeper, VA 22701; (800)541-2116, has recently announcedthat they have materials for thismethod available.

The University of California doesnot encourage environmental samplingof laying houses at this time. Thisinformation is provided for informa¬tion and does not indicate an en¬

dorsement of this or any supplier bythe University of California or

criticism of other suppliers ofsimilar products.

6

OSTRICH DISEASES

Ratites have become popular asalternative livestock in the UnitedStates. There is an increasing publicinterest in them. Ratites are

frequently moved interstate (forauctions and private sales) orintercontinental (for importation ofbreeding stock). Recent findings oftick vectors of Cowdria ruminantium,the rickettsial agent of heartwater,on newly imported ostriches promptedconcern by regulatory agencies. Thefollowing thoughts on known infectiousand parasitic diseases of ostrichesare discussed to inform those in¬

terested with these birds. Ostriches

are susceptible to Newcastle viruses,but not markedly. Other diseasesreported in ostriches, that also occurin other birds, include tuberculosis(Mycobacterium avium), avian pox,

aspergillosis, candidiasis, salmonel¬losis, pseudomoniasis, klebsiellosis,colibacillosis, pasteurellosis, staph¬ylococcosis, and chlamydiosis (in a

bird, kept in the same room withmacaws). Ostriches are also uniqueamong the avian species in that theyare susceptible to anthrax. Lice arehost specific for the ratites. Otherexternal parasites are not hostspecific. Intestinal coccidia(Isospora sp.) are of little clinicalimportance to ostriches and are notlikely to infect domestic poultry(which have Eimeria sp.).

(Excerpt from Dr. Murray E. Fowler'sarticle in Foreign Animal DiseaseReport, No. 18 (2), 1990).

EGG PROCESSING WORKSHOP PROCEEDINGSAVAILABLE

95616. If you would like to orderthis send a check for $5.00 payable toUC Regents, your complete mailingaddress and a note specifying thepublication which you want to Dr.Zeidler.

EXPERIMENTAL VACCINE FOR COCCIDIOSIS

According to the U.S. AgricultureDepartment, which developed anexperimental live vaccine againstcoccidiosis in young chickens, thevaccine appears to be 100% effectiveagainst the parasites which cause thedisease. Three versions of thevaccine were tested on 200 chickensand none became ill when exposed tothe target organisms. The vaccineconsists of live coccidial parasiteswhich have been irradiated with x-

rays. This renders them sterile andthus the coccidia are unable to

advance to the disease causing state.It is theorized that the sterile

parasites stimulate the chickens toproduce antibodies and activate immunecells to protect against futureinfections. The vaccine is presentlyundergoing further laboratory testingand field trials.

(Excerpt from Veterinary Product News,Vol. 3(1), January 1991).

Francine A. Bradley, February EditorArea Poultry Farm Advisor/Northern California

Department of Avian SciencesUniversity of CaliforniaDavis, California 95616(916) 752-6316

Proceedings of this workshop which washeld on January 16th at Riverside andJanuary 17th at Modesto are availablefrom Gideon Zeidler, Extension FoodEngineer, Food Science Department,University of California, Davis, CA

Ralph A. Ernst, Technical EditorExtension Poultry SpecialistDepartment of Avian SciencesUniversity of CaliforniaDavis, California 95616(916) 752-3513

7

U.C. Cooperative Extension2604 Ventura Avenue, Room 100Santa Rosa, CA 95403-2894

Non-Profit OrgU.S. Postage

PaidPermit No. 628Santa Rosa, CA

COOPERATIVE EXTENSION UNIVERSITY OF CALIFORNIA

CaliforniaPoultry LetterIN THIS ISSUE...

FEBRUARY 1991

A Food Editor's Thoughts On The Salmonella IssueThe Nation's Restaurant MenusVentilation And Toxic GasesSalmonella Pullorum—Still Around After 55 Years Of EradicationLamp Conversion RebatesUpdate On Avian Embryo VaccinationNew PublicationRe-Evaluation of Calcium, Phosphorus and Vitamin DFor Egg Shell Quality

SE Drag Swab Kit AvailableOstrich Diseases

Egg Processing Workshop Proceedings AvailableExperimental Vaccine For Coccidiosis

8