:!~;ii
I
'\ NOTES FOR THE GAME FARMING INDUSTRY:~;';::}@:fI
@1991 J.C. Haigh MRCVS
University of Saskatchewan
~,;\\-j
Mule deer
',\(i;
.~\
There
farming
is almost
of mule
numerous
by them.
reputed
One
yet the
species
farmland
been
have
section
as many
twins,
have
to an explosion
controlled
is one
and
ranch
and
been
that
in the
on the
of the
Alberta,
almost
sand
most
and
in
overrun
hills
~
l!;;;r-'
.j
even
born
has
have
not
by hunting..
In both Albertaand Saskatchewan,mule deerfarming is permitted,and a few operationshave been
started. Someof thesebeganwhen
trapping permitswere let in Alberta,and manyfarmersran into a
seriesof diseaseproblemswith theanimals.
Taxonomy
Mule deerand white-tailed deeraremembersof the
Odocoiliinae,a family of deerrestrictedto the Americas,
and within the genusOdocoileuslimited toto the two
speciesO. virginianus and O. hemionus,the latterbeing
the mule deerand its relatives,the variousforms of blacktailed deer.
Crossesbetweenmule deerand white-tailed deerare
known from the wild, and havecausedconsiderable
confusionfor huntersand wildlife controlofficers alike.
Recentwork with blood proteinsand DNA probeshas
allowed clear differentiationof the two species,and
Metatarsalglandsof Odocoileus
identificationof hybrid offspring. One externallyvisible
characteristicof the hybridsis that the gland on the
outsideof the lower leg (the metatarsalgland)hasan
appearance
half way betweenthat of the pure-bred
animals.
is
as 20,000
on
winters
it in 1991.
and the A high
of
that
and
information
Saskatchewan
30 odd
to have
percentage
been
deer,
ranch
head
series running
of easy
led
no published
in southern
areas
triplets,
(~;~,::;:;'!:
"~;:
Introduction
some
~
Distribution
Mule deerand their relatives
arefound in much of the western
half of the North America all the
way from Alaskato Mexico. It may
be that their failure to moveeastwardsis relatedto the fact that they
are susceptibleto brain-worm
infectioncarried by white-tailed deer
throughoutmost of the easternhalf
of the continent. By far the biggest
areafor anyparticularsub-speciesis
that coveringthe Rocky Mountain
statesof theUS and Alberta,the
westernhalf of Saskatchewan
and easternBritish Columbia on up into the southwestern
Yukon. Throughoutthis
areait is d1eRocky Mountainmule deerthatis found. It
appearsd1atd1emule deerin Saskatchewan
havegradually beenextendingd1eirrangenorthwards,and it is now
by no meansuncommonto seethem just north of
Saskatoon.
Handling
Mule deerare readily trappedinto feedingsites in
late winter, but their run down nutritional condition at this
time makesthem poorcandidatesfor survival of the
associatedstress. Modem trappingtechniques,insteadof
box trapping of individual animals,would probablyhave
led to lesstrouble after capturein the past. Becausemule
deerare sociableanimals,groupcapturein a training and
tamingscenewould probablybe the bestmethod.
On farms mule deertend to be lessindividualistic
thando white-taileddeer. They usuallyrun togetherin
looselyassociatedherds,but without the tightly knit
structureof a fallow deeror wapiti group. The exception
to this is for a period after fawning, whenindividual does
are very territorial andaggressive.For muchof the year
they can thereforebe handledin muchthe sameway as
Publicationsupportedby the Canada/Saskatchewan
ERDA agreement
GF-MD-I-OI
fallow deer. HoweverI have seenthem jump a2.1 metre
(7') fence when underpressure.The basicprinciple of
alleyways,the opportunityto flow aroundcomers,sight
boardsor shadenetting at pressurepoints,a walled yard
(slattedboardsto at least2.45 m or 8'), and a darkened
shedall apply.
lengthrangesfrom 189to 218 days,with an averageof
about203.
Drugs
Weights of adultmalesfluctuate very widely overthe
year,andthey lose as muchas20% of maximumweight
afterthe rut. Bled carcassweightsaverage74 kg, but
maximumweightsas high as 159kg liveweight for a tame
buck,and 112kg bled carcassweight for a wild buckhave
beenrecorded.
In commonwith manydeer,femalesmay come into
estruswhenthey reachabout70% of adult weight There
are not manydataon matureliveweightsof does,but the
averagebled carcassweight of shotRocky Mountainmule
Opinionsvary on the actualhandlinginside sheds.In deerdoesis about60 kg, which would indicatea
liveweight not muchover65 kg. Maximumsas high as 86
the daysbeforedrug immobilizationwas commonin zoos
kg liveweight,and 76 kg carcassweighthave been
and researchcentresthesedeerwere commonlyhandled
by beingcrowdedinto small compartmentsin dimly lit
recorded. It is well recognizedthat well grown whitesheds. Theycould be handledby applying lateralpressure tailed deerfawns mayconceivein their first year of life,
againsta wall, and downwardpressureoverthe shoulders but this is apparentlylesscommon,althoughpossible,in
and back. If they fell, or turned,so that their feetcame
free-rangingmule deer. On farms the experiencehasbeen
thatthesedoe fawns will conceiveif not separatedfrom
free theywould inflict rapid kicks with their very sharp
hooves. I havehandledmule deerin darkchutecompartthe bucks. Eventhe buck fawnsmay befertile at lessthan
ments,and it absolutelynecessaryto keeppressureon
12 monthsof age. If doefawnsare born in Junethey may
their backsin orderto deal with them.
grow fast enough,undergood nutritional conditions,to
comeinto heatby the ageof about7 months,and so
A better option is to run them into darkenedsheds
conceiveas fawns,albeit laterthan maturedoes. The
wherethe ONLY light sourceis controlled by humans. In
fawns born to the 13 to 16 monthold animals will of
the rotundaa red light can be used,andallows handlersto
coursearrive very late in the year,and in the wild they
go in with the deer. Other lights shouldbe on a dimmer
might not survive. On farmsthey are likely to perform
switch. The deerwill run up a chutetowardslight, but not lessthan optimally, particularlyas their motherswill lack
as readily as fallow deer,and may needpersuasionto
good quality grazing in orderto producemilk.
move. They can easilybe handledin a drop floor chute!
squeeze.Light pressureon the backallows complete
Not only are the fawns likely to performinadcontroland manyprocedurescanbe carriedout. Alequately,but their mothersmay not regainsufficient
thoughI have not seenone reported,a chuteand squeeze
conditionto breedin their secondNovemberof life. Allsimilar to the one usedfor white-tailed deerat Houghton
in-all it is probablybetterto restrictthe breedingof doe
Lake in Michigan, a photo of which is reproducedin the
fawns. This can eitherbe doneby separatingthem from
pamphleton white-tailed deer(GF-WT -1), is likely to be
bucksby the end of December,which will meanthat a
effective.
proportionof the early born rapidly grown fawns will
conceive,or by weaningthembeforethe rut, andensuring
Thereis little doubt that thesedeerare susceptibleto
that theydo not conceiveuntil theyare 16 monthsof age.
the stressesassociatedwith handling,and a good quiet
Until more informationon diet and managementon farms
routine, with minimal noiseand disruption,is important.
is generatedhe practiceof aiming for more fawns by
Deer that are handledroughly may take severalweeksto
running everythingtogetherin one paddockshould
recovercondition.
probablybeviewed with caution.
In commonwith virtually all othermedicationsused
on deer,thereare no licensedproductsavailablefor mule
deer. ThosewhiC;hwork well include xylazine HCI, or
mixtures of opioids and xylazine. Similar dosesto those
usedfor wapiti are effective,and vary accordingto the
tamenessof the animal and its degreeof confinement
whentreated. Yohimbine works satisfactorilyas an
antidoteto xylazine.
Reproduction
Mule deer,like all deerfrom temperatezones,are
shortdaybreeders.The onsetof the rut differs throughout
the continent,but for mostareasthe peakoccursin mid to
late Novemberand early December. Howeverin some
regions of California it maybe as muchasa month later
thanthis. The breedingseason,when either sexmay be
fertile, extendsfor a much longerperiod, eveninto late
Februaryand early March in somecases. The gestation
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Birth weightsof fawnsdependupon whethersingle
or multiple births occur, singletonfawns usuallybeing
considerablyheavierthan twins or triplets. Male fawns
are usuallyheavierthanfemales,3:tleastwhentwins of
eithersexare born. The rangeof averagebirth weights
from severalstudiesis from 2.74to 3.99 kg, with individualsranging from 2.27 to 5.0 kg.
Nutrition
Mule deeraremixed feeders,tendingtowardsthe
concentrateselectorend of the spectrum,but, like whitetailed deer,quite happyto spendconsiderableamountsof
time in summerhayfields grazing. In commonwith
othertemperatezone deermule deerlose weight in winter,
evenif offered high quality diets. For farmeddeer,
artificial rations thatensurean adequatemix of protein,
carbohydrate,fat, fibre and mineral / vitamin mixesare
essential,asthe animalsare in no position to selectthe
wide rangeof forageavailableto them in the wild. Little
researchhasbeendone to show how to maintaindeeron
farms,but the ration suggestedfor white-taileddeer,and
outlined in pamphletGF-F-3,hasprovedto be an excellent one for a numberof zoo animals.This rationis based
uponthe deerration developedat Michigan Stateuniversity, and is widely usedfor captiveruminantsin zoos. If it
is offered togetherwith a good quality alfalfa hay,productivity is high and diseaseincidencelow. In summer
consumptionof the ration will decline sharplyif thereis
good quality grazingavailable. Mule deerwill also
readily acceptoats,but this shouldprobablynot be the
only grain componentof a ration on a yearroundbasis.
At times of high demand,during lactation,and at weaning
of fawns,a 16-17%protein ration is optimum. Thereis
little doubt that an adequatefibre contentof the ration is
essential.
Problems
The mainproblemsencounteredby thosewho
maintainmule deerin captivity arehandlingstressand
parasitesusceptibility.Handling stresshasalreadybeen
discussed,and it is clear thatmule deerfarmerswill have
to go throughsomeof the samelearningprocessesthat
fallow deerfarmersexperienceda few yearsago. Parasite
controlis discussedbelow.
Andrew Breunig,who farms mule deerin Albertahas
also seendominanceexhibited by somedoesduring the
fawning season,which hasled to somedoesbeingunable
to grazeor gain accessto adequatenourishment.Dominantdoes,often the first to fawn, wil!., for about6 weeks,
occupya small (2-4 acre) territory,and hardly allow
anotheranimal to crossit. The net effectof this is that
subordinatedoescannotget enoughgood quality forageto
supporttheir fawnsoptimally. This problemhas not been
seenin zoo situations,but the increasedcrowding may
havepreventedit. A solutionmight be to penfawning
doesseparately,as is done at HoughtonLake for whitetailed deer. This would of coursebe very expensive.
Alternatively, a substantialnumberof portablefeederscan
be placedin fawning paddocksso that all doescanfind
one. Unfortunatelythis will increaselabourcosts.
Hemorrhal!icdiseases
Mule deerare susceptibleto bothbluetongueand
epizOOtichemorrhagicdiseasesof deer,but to a lesser
extentthanwhite-taileddeer.They are transmittedby
gnats(Culicoides). Neitherdiseasehasbeenseenin
Canadasince 1975,whenBluetongueoccurredin the
OkanaganValley. They are probablynot importantas
diseasesof farmeddeerin Canada,but mayoccur further
south. Any deerbeing imported from the USA shouldno
doubtbe tested.
Necrobacillosis
Mule deer,especiallystressedanimals,are very
susceptibleto necrobacillosis(GF-S-5). Therehavebeen
outbreaksin which entire researchherdswere lost to this
conditionoverthe courseof a few weeks. Affected
animalsare often seenwith rough starycoats,looking
depressed,
and losingcondition. If therearelesionsin the
mouthor respiratorytractexcesssalivationand/orharsh
breathingwill be noticed,and there will be exercise
intolerance.Vigorous early treatmentis essential.If
lesionsarevisible in the mouth,they canbe debridedand
flushedwith hydrogenperoxide. The bacteriumis
susceptibleto severalantibiotics,so thatcultureis probably important.to ensurethe right choice,and an adequate
doseis a must.
Bacterialoneumonia
Severalspeciesof bacteriamaybe involved in cases
of pneumonia.In particular,Pasteurella and
Fusobacteriumplaya role. Clinical signsare similar to
thoseof necrobacillosis,with harshbreathingusually
beingevident. Treatmentis similar to that for
necrobacillosis,but may befutile if not initiated early in
the course.
Parasites
Therearetwo classesof parasiteswith which the
mule deerfarmermustbe particularlyconcerned.The
fIrst two do notoccur in Canada,and are really of concern
only in that importationof the deerfrom the USA maybe
proscribed,eitherentirely, or at certaintimes of year.
Mule deerare susceptibleto brainworminfection (GF-S2), which may explainwhy theyhave not becomeestablished, either in the wild or on farms,wherethis parasite
occurs. The otherparasitethat doesnot occur in Canada,
but is importantin relation to mule deer,is the arterial
worm Elaeophoraschneideri.This parasiteis found
certainareasof in a numberof statesof the USA. It is
transmittedfrom deerto deer,and to otherspeciesby
Diseases
biting flies, particularlytabanidflies. Mule deershowno
Thereis a long list of diseaseto which mule deerare
clinical signs,as the parasiteappearsto haveevolveda
susceptible.The morecrowded their conditions,andthe
relationshipwith them overthe centuries. Whenthe
less well that they arelooked after, especiallyin termsof
parasiteis transmittedto otherspecies,it maybecome
nutrition, the more likely is thatthesediseaseswill assume very important,as it may entirely block arteries,especially
importance. It would be pointlessto list all of them but
to regionsof the head,including the muzzle,brain, or
someoutline noteson a few areincludedbelow.
antlersor eyes. One of the namesfor the resultingclinical
conditionin wapiti is clear-eyedblindness. A recent
outbreakof arterial worm diseasein Arkansascausedall
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red deerfawns to die within about2 weeksof birth.
Hinds that had calvedwere also affected,showingsevere
neurologicsigns. Wapiti are also affected.and may suffer
extensivenecrosisof areasto which arterial supplyhas
beenblocked by the adult or larval stagesof the worm.
Sheepand goatsmay also developlesions.The condition
in the former is known as sorehead.
Diagnosisin the living mule deeris possible,usinga
biopsy takenfrom the forehead,but care mustbe taken
both in obtainingthe biopsy, and in its interpretation.No
treatmenthas beendescribed.
Neither of thesediseasesis of directimportanceto
the Canadianmule deerfarmer, but gastrointestinal
nematodes,lungwormand coccidia mayhavea direct
impact uponstock. Routine checksfor nematodeinfections shouldbe carried out in the summermonths,especially in warm wet years. Both types of parasitecancause
seriousproblems.
intestine. T~ir imp~ce as agentsof diseasedepends
upon
a numberof in~!ac9ng
the
accompariying
table:' .factors thatareoutlined in
Coccidia
areprotozoan
that
are well
known
in several
domestic
species.'parasites
Most deer
harbour
them
but
Elaeophoraschneideri in the artery of a mule deer
Lungworm infection of mule deerhasnot beenas
closelystudiedas it has in red deerand wapiti, but if the
syndromeis similar, there will notbe the coughingand
husk-like symptomsassociatedwith this diseasein cattle,
but ratherthe build up of adultparasitesin the bronchial
tree,which will lead to an accumulationof froth surrounding the worms, and the blockageof the airways. The main
presentingsign will be loss of condition. New Zealand
scientistshave shownthatlevamisoleis inappropriatefor
the treatmentof red deerparasitism. A betterchoiceis
likely to be ivermectin, but the efficacy of the various
forms, injectable,oral and topical, has not beenadequatelytestedin deer. Andrew Breunigreports thatthe
topical preparationis unsuitableat certaintimes of year,
especiallywhenthe summercoatis present.
GasU'ointestinal
nematodescanalso causedebility
and diarrheain mule deer. Severalspecieshavebeen
reportedfrom wild deer. They mainly belongto the
Ostertagiinae,and parasitizethe abomasumand small
it appearsthatthe only report of clinical diseaseclearly
linked to coccidia in deercomesfrom mule deer. Thereis
little doubtthatthe samesort of interactingfactorsas for
intes~~al.wormswill ~I?pa~t:VFon
the onsetof clinical
coccIdioSIS.
The condItionIScommonly seenaround
fawning time, especiallyifoonditions are muddy,andlate
in winter or at springthaV)::;when
young animalsarebeing
weanedandare finding the competitionfor food rather
severe.Clinical signsare usuallylimited to a rough coat,
lossof condition,anddiarrhea. Treatmentwith appropriatesulfa drugs,Ofarnproliurn,will effecta temporary
cure, but it is almostimpossibleto eradicatethe disease
once it appearsin~ herd. Control with coccidiostatsin
feedis possible.Greatcare musthoweverbe exercised
with monensift;~s'overdoseis oftenfatal. An alternative
coccidiostatis Decoxx,which appearsto be rathersafe.
Any feedincorporateddrug is limited in efficacy both by
the ampuntof feed thatan individual deermay eat,and by
the level of challenge. Subordinatedeermay not beable
to gai~ accesstofeeders,so thatcare in distribution must
be exercised.If breakthroughsoccur it is possibleand
effectiveto usean alternativedrug for short-termtreatment.
Bibliography
Wallmo, O.C. (ed) Mule and Black-tailed Deer of North
America. A Wildlife Managementlnstitue Book. University of NebraskaPress.Lincoln.
Photocredits
Fig 1,2. J.C. Haigh. Fig3. C.P.Hibler
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