Low fertility inturkeys,resulting from unsuccessful mating as a consequence of large,heavily
muscled birds or of reduced libido, is a serious and costly problem in the production of
hatchingeggs.Artificialinsemination(AI)iswidelyusedtoovercomethisproblem.AIhasnot
found wide application in chickens but is routinely used in special breeding work.
Collecting semen from a chicken or turkey is done by stimulating the copulatory organ to
protrudebymassaging theabdomen and the backover the testes. This is followed quicklyby
pushingthetailforwardwithonehandand,atthesametime,usingthethumbandforefinger
ofthesamehand to “milk”semenfromtheductsofthisorgan.Semen flowresponseis
quicker and easier to stimulate in chickens than in turkeys. The semen may be collected with
anaspirator orinasmall tube or anycup-like container. In turkeys, the volume averages
~0.35-0.5 mL, with a spermatozoon concentration of 6 to >8 billion/mL. In
chickens, volume is 2-3 times that of turkeys, but the concentration is about
one-half. Collected semen is usually pooled.
Chickenandturkeysemenbegintolosefertilizingabilitywhenstored>1hr.Liquidcold(4°C)
storage of turkey and chicken semen can be used to transport semen and maintain
spermatozoal viability for ~6-12 hr. When using liquid cold storage for >1 hr, turkey semen
must be diluted with a semen extender at least 1:1 and then agitated slowly (150 rpm) to
facilitate oxygenation; chicken semen should be diluted and then cooled—agitation is not
necessary. Several commercial semen extenders are available and are routinely used,
particularly for turkeys. Extenders enable more precise control over inseminating dose and
facilitate filling of tubes. Results may be comparable to those using undiluted semen when
product directions are followed. Dilution should result in an insemination dose containing
~300 million viable spermatozoa.
For insemination, pressure is applied to the left side of the abdomen around the vent. This
causes the cloaca to evert and the oviduct to protrude so that a syringe or plastic straw can
be inserted ~1 in. (2.5 cm) into the oviduct and the appropriate amount of semen delivered.
As the semen is expelled by the inseminator, pressure around the vent is released, which
assists the hen in retaining sperm in the vagina or the oviduct. Due to the high sperm
concentration of turkey semen, 0.025 mL (~2 billion spermatozoa) of undiluted pooled
semen, inseminated at regular intervals of 10-14 days, yields optimal fertility. In chickens,
due to the lower spermatozoon concentration and shorter duration of fertility, 0.05 mL of
undilutedpooledsemen,at intervalsof7 days,isrequired.Thehen’ssquatting behavior
indicates receptivity and the time for the first insemination. For maximal fertility,
inseminations maybe started before the initial oviposition.Fertilitytends to decrease later in
theseason;therefore,itmaybejustifiedtoinseminatemorefrequentlyorusemorecellsper
insemination dose.
Chicken and turkey semen may be frozen, but reduced fertility limits usage to special
breeding projects. Under experimental conditions, fertility levels of 90% have been obtained
in hens inseminated at 3-day intervals with 400-500 million frozen-thawed chicken
spermatozoa.
Oneofthesub-headingsin‘TheSpecialistChickSexer’statesNeverleadastudentwhereyouhave
neverbeenyourself.InthisessayIambreakingthisgoldenruleofteaching:whileIhavebloodtested
hensforpullorum,vaccinatedchickens,debeaked,dubbedcockerels,surgicallycaponizedcockerels,
selectedbirdsforbreeding,andofcoursebeenacommercialchicksexer,Ihaveneverdoneany
artificialinseminationofpoultry;norhaveIeverseenanyoneelseperformingtheoperation.
InthisessayIamwritingpurelyfrommyreadingofotherwritersonthesubject.Beforeattemptingto
carryoutanyartificialinseminationonyourownbirdsyouwouldbeadvicetofindoutmeaboutwhat
isrequired.HereIcanonlygivethereadersomeideaofwhatisrequired,andgenerallyhowitis
carriedout.Ifanyviewer/readerhasanyreadingreferences,orotherhelpfulinformationonthesubject
theywouldliketoshareitonthiswebsiteforotherstoread, Iwouldbedelightedtohearfromyou.My
ownsourcesofinformationarelistedattheendofthisessay.
ArtificialinseminationwasfirstpracticedinAmericaduringthe1920’sandbecamewidelyusedin
Australiawiththeintroductionoflayingcagesinthelate1950s.
Someoftheadvantagesthathavebeenclaimedforartificialinseminationinthepasthavebeen:
� Increasedmatingratio:Inaflockitisusuallyonecockerelmatedtosixtotenhens.With
artificialinseminationitisclaimedthisratiocouldbeincreasedfourfold.Inbothcasesit
dependsonthestrainandbreedofthebirds.Inmycommercialfarmingdayswithwhite
leghorncockerelsIusedfromfivetosevencockerelswithapenofahundredhens.When
heavymeatbirdscamealongit wasaboutonecockereltoabouteightortenhensinalarge
flock.
� Useofoldermalesfromoutstandingperformers:Oldermalebirdsthathavebeenflock
improverscanbeusedforseveralgenerations.Whereasundernaturalmatingtheirusefullife
islimited.
� Abletouseaninjuredbird:Valuablemalebirdsthathavebeeninjuredinthelegcanstillbe
usedforartificialinsemination.
� Eliminationofpreferentialmating: Whenthereispoorfertilitycausebypreferentialmatingit
canbeeliminated.
� Layingcagescanbeused:Layingcagesarenolongeraproblemwhenfertileeggsareneeded.
Selectedhenscanbeinseminatedandremaininthecage.Theexactpedigreeofthechickens
hatchedfromthesefertileeggsisknown.Severalcommercialfarmsusedcolonycageswith
severalhensandonerooster,fertilityalwaysseemedtobeaproblem;artificialinsemination
didsolvethisproblemforsome,untilthistypeofhousingwentoutoffavourgenerally.
Althoughthereisstillonelargefarmonlyanhoursdrivefrommyofficethatstillusesthis
systemforitsbreedingstock.Seethephotoofacolonycagefrommyfarm,whichIusedfor
layersbutnotforbreedingpurposes.
� Successfulcrossbreeding:Usuallycrossbreedingisverysuccessfulundernaturalconditions,
butsometimesthereisakindofcolourdiscrimination:somehenswillnotmatewithamaleof
adifferentcolourunlesstheyhavebeenrearedtogether.Duringmycommercialpoultry
farmingwhenthewhiteleghornAustralorpcrosswerethelayersoftheday,Ialwaysreared
thewhiteleghorncockerelswiththeAustralorppulletsrightfromdayoldonwards.This
practiceproducedverygoodfertilityinthiscross.Butforsmallbreedersorpoultryfanciers
rearingthemtogetherisnotalwayspossible,artificialinseminationcouldbeasolutiontoa
fertilityproblem.
Recommendedhousingoftherooster.
Themalebirdscanbehousedinindividualcages,buttheyneedtohaveenoughroomtobeableto
crow.
Asuggestedcagesizeis45emwide,60cmdeepand60cmhigh.Thefeedandwatercontainersshould
behungontheoutsideofthecage.Malebirdsrespondtothepeoplehandlingthemandaquiet,
unhurriedapproachisnecessarywithcarefulhandling.Duringthecollectionofsemen,itisessential
thatvisitorsremainoutsidetheshed.Thiswillpreventthebirdsfrombecomingfrightened.Itisagood
ideathatthemalesarehousedinclose-proximitytothehenssothatthetimebetweencollectionandinseminationiskepttoaminimum.Priortouse,theselectedmalebirdsshouldbeexaminedforexternal
parasites,particularlypoultrylice,andtreatedaccordingly.Itisalsoagoodideatoclipthefeathers
fromaroundtheventareatogiveeasyaccesstothemaleorgan.Thisappliesparticularlyto
loose-featheredbreedsofpoultry.
SemenCollection.
Forthisoperationtwopeopleareneeded,oneforholdingandcollectingthesemen(holder),theother
(operator)tostimulatethecontrolflowofsemen.Theholderreststhemalebird'skeelon thepalmof
hisrighthandinahorizontalpositionsothattheheadisbetweentheholder'ssideandelbow,thebird's
legsbeingfreetomove.Itisimportanttoholdthemalebird1ooselytogainthedesiredresult.The
holder'slefthandisusedtocollectthesemen.
Theoperatorholdstherooster'slegslooselybutfirmlyinhisrighthandandstrokesthebackofthebird
fromnecktotallwithhislefthand.Thestrokeisfirmbutnottightandthefingersandthumbfol-low
thelateralcontoursofthebody.Afterafewstrokes,themaleorganswellsandprotrudesoutwardsand
downwards.Thewhitesemenwillheseeninthecentralfurrowoftheorgan.Thesemenismilkeddown
byfirmfingerpressureeithersideoftheventintothecollectingtube.
Themalebirdshouldhemilkedthreeorfourtimesbeforeinseminationisrequiredtochecksemen
quantityandcolour.Ifthemalebirdrefusestoproducesemenafter10daysofhandlingorifthesemen,
whichshouldbewhite,isdiscolouredduetocontaminationbyfaecalmaterialorblood,thenitis
probablyuselesstoperseverewithhim.
InseminationoftheHen.
Thehenisheldbythelefthandbeingplacedoverthebreastwiththebird'sbackforcedagainstthe
holder'sbody,theheadpointingtotheground.Therighthandisplacedovertheventsothatthethumb
isaboveandforefingerbelowthevent.Asuddenpressureexertedaroundthebreastareaand,atthe
sametime,usingthethumbandforefingertospreadapartthecloaca,resultingintheturningofthe
cloacainsideout.Theoperator,with0.1miofsemenor0.2miofdilutedsemen(inPBSorsaline)
drawnupintheinseminatingtube,placesthistubeasfaraspossibleintheexposedoviductopening
seenattheleftsideoftheintestinalopening.Thesemenisintroducedatthesametimeastheholder
releasesthepressureandthecloacareturnstoitsnormalposition. Usuallythesemenfrom1roostercan
beusedfor40-50hens.
RegularityofInsemination.
Inseminationsshouldbecarriedoutontwoconsecutivedaysthefirstweekandthenonceeachweek
thereafterwhilefertileeggsarerequired.
Aspoultrysemenhasaverylimitedlife,inseminationofhensshouldhecompletewithinonehourof
semencollection.
Itisagoodideatocarryouttheoperationatthesametimeeachday,thebesttimebeingbetween
2.00pmand4.00pm.Thereasonforthisisthatduringthemorning,mosthenshaveanegginthe
oviduct,thusobstructingthefreepassageofsementotheovary.Anotherpointinfavourof
inseminatingthehensintheafternoonisthatitisgenerallycoolerandthehensarelesslikelytobe
affectedbyheat,particularlyinlatespring.
Observationhasshownthateggsarefertileaftertheseconddayofinseminationandcanremainfertile
fortwoweeksormore.Ifanothermaleistobeusedonthesameheninabreedingprogram,itis
suggestedthataperiodofthreeweekselapsebeforethesecondmaleisused.
Iflargenumbersofmalebirdsaretobeusedforartificialinsemination,itissuggestedthat,priorto
theiruse,asampleofthesemenheexaminedunderamicroscopetocheckspermmotilityasthemisa
goodcorrelationbetweenspermmovementandfertility.
EquipmentRequired.
Theequipmentneednotbelavishorexpensive.Itconsistsofaglassorplastictesttubeforcollecting
semenfromthemale,a3cchypodermicsyringewith0.1mlgraduations,arubberconnection(bicycle
valverubber),anda0.5cmexternaldiameterglassinseminatingtube9cminlength.Sometimes,a
smallplasticfunnelisusedwheresemencollectionmaybedifficult.Equipmentisillustratedbelow.
ArtificialInseminationEquipmentFromtop,clockwise:Syringewithinseminatingtubeandrubber
connection.Ringer'sSolution.GlassTube
Inordertoincreasethenumberofhensthatcanbeinseminatedfromthesamerooster,thesemenmay
bedilutedwithasolutionknownasmodifiedRinger'ssolution.Thecompositionofthissolutionisas
follows:
� Sodiumchloride68grams
� Potassiumchloride17.33grams
� Calciumchloride6.42grams
� Magnesiumsulphate2.50grams
� Sodiumbicarbonate24.50grams
� Distilledwater10000cc
Ratherthangotothe troubleandexpenseofpreparingthissolution,itcanbepurchasedfromsome
pharmaceuticalcompanies.Thedegreetowhichsemencanbedilutedisintheratioofone partsemen
to2partsdiluent.
NorthAmericanscientistshavediscoveredthelongestbirdpenisever-a42.5cmorgan
belongingtoaduck.DrKevinMcCrackenandcolleagueshavefoundaspecimenofthe
Argentinelakeduck(Oxyuravittata)thathasapenisaslongasitsbody-nearlyhalfametre
long.Thishasextendedanearlierestimateofthelengthoftheduck'scorkscrew-shapedpenis,
whichwas20cm.
"It'safascinatingbitofanatomythey'vediscoveredhere.Itreallyisunusual,"commented
birdmatingexpertDrRaoulMulderfromtheUniversityofMelbourne.
Mostmalebirdsdon'thavepenises-theycopulatebybrieflytouchinggenitalopenings,
calleda'cloacalkiss',"heexplained.
DrMuldersaidanumberofduckspeciesandostricheshavepenises,butthiswasdefinitely
thelongesteverencountered.DrMcCrackenandcolleaguesspeculatethatthegiantpenis
maybeanexampleof'runaway'sexualselection,wherefemalepreferencedrivesmale
anatomytoever-greaterextremes,asinthepeacock'stail.
DrMulderbelievesthismaybeabitofanthropomorphising,however.
"I'mnotfondofthe'nudgenudge,winkwink'commentsbytheauthors,"hesaid.
Theauthorswritethatthisspeciesis"promiscuousandboisterousintheirsexualactivity",
whichmeansthatthereislikelytobestiffcompetitionbydrakestobethefatherofducklings.
Onefindinginsupportofthisidea,theysuggest,isthatthedrake'spenishasabrush-liketip,
whichtheysaythemalesprobablyusetoscrubthespermofpreviousmatesfromthefemale's
oviduct.Mulderagreedthiswaslikely,butfeltanothersuggestionbytheauthors-thatmales
mightuseanevertedpenisasa"display"toattractfemales-wasnot.
"Theyarebeingratherspeculative,anditseemsnotmuchisknownaboutthisbirdandwe
needtoobserveitsbehaviourinthewildbeforewecanunderstandwhatfunctionthispenis
mighthave,"hesaid.
Theauthorsacknowledgethatmanyquestionsremain:Howmuchofthepenisdoesthedrake
actuallyinsert?Anddoestheanatomyofthefemalemakethemunusuallydifficultto
inseminate?
Theyconclude,nevertheless,thattheirnewspecimenwillhelpthembetterunderstandsexual
selectionandspermcompetitioninbirds.
