sheep Flashcards
domestic sheep are (scientific name)
ovis aries
(there are 6 other species of wild sheep_
sheep are
even toed ungulate ruminants
ewe
female
ram
intact male
wether
castrated male
lamb
younger than 12 months
hogget/ mutton
once permanent incisors in wear:
hogget (animal) or mutton (meat product)
polled
hornless
national number of sheep
currently up
where are 1/2 of australias sheep
in NSW and victoria
most farms have (in terms of size)
relatively small flocks (~2500 head)
wool production is declining due to
- fluctuating wool prices
- competition from other enterprises, including meat
- drought
how much of aus wool is exported
98%
fleece is made up of
individual fibres grown by follicles
what determines the characteristics of wool produced
follicle makeup (ex bulb size, follicle number, density)
nutrition (mostly protein) is a major factor influencing
wool growth, it takes about 3 months to be relfected
true or false sheep originally evolved to shed fleece
true; this has been bred out of them
wool biology from out to in
outer membrane
cuticle
cortex
medulla
wool characteristics
- diameter is most important (micron)
- measures the average diameter in um of wool fibres in.a sales lot
- increasing demand for lower diameter; aus shifting focus to finer wool
- constant plane of nutrition needed to minimize deviations in diameter along fibre
what is a fine wool
less than 20 um
staple length
length of un unshorn lock of wool
staple strength
force required to break a staple; closely related to diameter variability
tender wool
has weak spots, low staple strength
position of break
where wool breaks during strength tests
related to diameter variability
breaks in the middle are not ideal
what is heavy contamination of vegetable matter in wool
more than 2% weight
lowers value of wool
costly to remove
what three things feed into profitability of wool enterprises
- feed (availability and digestibility)
- stocking rate
- lambing percent
major production driver for wool is
stocking rate
the amount of wool being produced is increasing in australia
false; number of sheep going up but wool production going down
aus sheep meat industry, whats going up whats going down
- Mutton production; decreasing
- Lamb production; increasing
hock
important for handling, middle back of leg
loin
middle/lower back; important cut of meat
dry ewe
no lamb
wet ewe
has lamb, lactating, full udder
how to sex sheep
- female has pink triangular vulva
- intact male have large testes that almost look like udder
- males also have teets
- females also have horns, so be careful
prime lamb aka lamb
- meat from sheep younger than one year
- preferred over mutton
- pink to pale red coloured
- tender, mild flavour
- grilled, braised or roasted
mutton
- meat from sheep 1-3 yo
- pop in middle east and europe
- deep red, lots of fat
- strong flavour, gamey
- best for slow cooking
store
sheep in moderate condition, will typically be sold at auction either for future breeding or finishing
finishing
targeted feeding (on pasture or in a feedlots) of sheep tor each desired weight and fat cover
general meat lamb lifecycle
- new born lamb
- 8-14 weeks sucker/ weaner, over 20kg
- another 4 weeks later store maintenance
- depending on target system for timing but then finishing to become finished lamb
how much of aus sheep meat is exported? what are the biggest markets?
73%
china, us and uae
live export
- transported by boat
- 1 million per year, 97% from WA
- largely to middle east
- allows for all parts of animal to be used
- local job creation
- reduced cost
- religious requirements
meat quality want to assess
leanness, muscularity and quality
how do you judge meat quality
- carcase yield ( fat thickness and distribution vs muscle)
- muscle development (legs, loin, shoulder, ribs)
- colour and firmness (meat and fat)
what 3 things feed into profitability for sheep meat/ lamb meat enterprises
output (kg) per joining, stocking rate and growth rate
major production driver for meat is
growth rate
(genetics, lactation of ewes, feed availability/ quality)
maternal sire
rams of this breed are crossed to produced good mothers (for rearing lambs)
terminal sire
rams of this breed are crossed to produce good lamb for eating
terminal= offspring are terminated
wool breed
merino (also used for mutton and lamb)
maternal sire breeds
- border leicester
- coopworth
terminal sire breeds
- poll dorset
- texel
- suffolk
way to classify sheep breeds
- merino
- british long wool
- british short wool
- dual purpose
- shedding
merino
- different strains such as spanish, saxon, peppin, south aus, vermont, rambouillet
- merino are predominant breed in aus (>80%)
- developed and used extensively for wool, but also used for mutton and lamb
border leicester
- british long wool
- coarse wool large frame
- most popular first cross sires
romney (marsh)
- british long wool
- coarse wool, large frame
- excellent mothers, used for prime lamb
breeds of british long wool
- border leicester
- romney (marsh)
- english leicester
- lincoln
- cheviot - terminal sire
poll dorset
- british short wool
- most popular prime lab (terminal) sires
suffolk/ white suffolk
- british short wool
- suffolk have white wool, black faces and feet
- white suffolk all white; developed for aus conditions, very hardy
british short wool breeds
- poll dorset
- suffolk/ white suffolk
- southdown
- texel
dual purpose breeds
- corriedale
- polwarth
- coopworth
shedding breeds
- wiltshire; english, less hardy
- dorper; south african; hardy
self replacing
- One of Most common type of production system
- Breed doesn’t matter
- Breeding and ram and a ewe of same breed: Rams purchased in; new genetics into flock
- Produces a pure-bred lamb → become ewes, rams and wethers
- Ewes are kept in a self replacing flock; they grow into adults we get wool from but we also breed them, they end up in same position as their mothers
- May not keep all ewe lambs however, because it’s an opportunity for selection (ex may cull ones w lower quality wool etc)
- Males are sold (as producers or meat)
- Some people will keep the males, particularly if they are wethers (castrated) not for breeding, because want to bring in outside genetics, keep them for wool only
- Sources of income:
wether/ram sales
Wool (ewes, rams)
Meat (from the culls ie the females we don’t want to select for or males too)
first cross
- Start mixing breeds
- Ewe of any breed mixed with maternal sire ram
- Produces a first cross lamb ; first cross ewes may be used as prime lambs (meat +/- wool) or used for breeding (goes into second cross)
- Male lambs end up as prime lamb (meat)
- Income:
First cross ewe sales
Meat (prime lamb, culls)
second cross
- breed a first cross ewe and a terminal sire ram
- Produces a second cross lamb which are ALL used for prime lamb meat
- why its called terminal sire ram because offspring are terminated lol they are only used for meat)
- income
Wool (first cross ewes)
Meat (prime lamb, culls)
wether flock sources of income
wool or meat from culls
Australian sheep breeding values (ASBVs)
Better breeding values; better genetics; better offspring etc
A lot more informed purchasing of sheep, more evidence based
new technology
- Smart tags;
Real time location; resource utilization
Mating and progeny records
Alert system (estrus, lambing, predation) - Remote monitoring
Ex walk over weigh, trough camera
Minimizing labor requirements
Increasing sheep welfare - Farm wifi
Allows an integrated tech based precision approach to farming
4 major health concerns in sheep productions
internal parasites
external parasites
infectious disease
foot disease
internal parasites notable examples
- barbers pole worm
- black scour worm
- small brown stomach worm
- thin- necked intestinal worm
internal parasites symptoms
anaemia
bottle jaw (oedema)
scours
internal parasites treatment
anthelmintic drench
internal parasites preventative husbandry
- monitoring worm burden
- rotational grazing
external parasites notable examples
- sheep lice
- blowflies
external parasites symptoms
- itching, wool rubbing
- dullness/ depression, kicking and tail shaking
- stain wool and skin lesions
external parasites treatment
- insecticide
- shearing
- antibiotics/ anti-inflammatories for fly strike
external parasites preventative husbandry
- tail docking and mulesing
- crutching
- insecticide
infectious disease notable examples
- johne’s disease (OJD)
- clostridial disease (tetanus, blackleg, pulpy kidney)
- ovine brucellosis
- foot and mouth disease
infectious disease symptoms
disease dependent: wasting, dullness, depression, dehydration, infertility, abortion
infectious disease treatment
- drug based treatment
- supportive care
- euth
infectious disease preventative husbandry
- vaccine
- biosecurity
foot disease notable examples
- foot rot
- assesses
- shelly hoof
foot disease symptoms
- lameness
- red and weepy between toes
- separation of horn from foot
foot disease treatment
- footbathing, antibiotics
foot disease preventative husbandry
- foot trimming (paring)
- grazing management in wet conditions
routine husbandry in sheep: general
- lamb marking
- shearing
- weaning
routine husbandry in sheep: health relaed
- jetting/ dipping/ backlining
- drenching
- vaccination
- foot care
routine husbandry in sheep: reproduction
- joining/ AI
- preg scanning
- wet drying
life cycle husbandry procedures is
lamb marking –> weaning –> annual cycle
what does annual cycle consist of
- crutching
- drenching
- joining
- shearing
- preg scanning
- vaccination
lamb marking procedures
- vaccine
- ear tagging, ear marking
- castration
- tail docking
- mulesing
recommended age for lamb marking
2-8 weeks ideal
before 12 weeks preferable
vaccines for preg ewes
to give lambs passive immunity until lamb marking where lambs are vaccinated
lamb marking vaccines
5 in 1 or 7 in 1
gudair
scabigard
lamb marking ear tagging
- ID tag; RFID for NLIS; mandatory
- may also do notch on ear
- tag colours based on year of birth with 8 yr rotation
- males tag in left ear, females tag in right
lamb marking- castration
- ease of management; less aggression and no unwanted mating
- improvements in meat quality
- 98% done w rubber ring
- 2% surgical
- surgical removal involves cutting into scrotum, and TEARING testes not cutting
lamb marking; tail docking
- removal of distal tail
- reduce risk of flystrike due to build up of feces/ urine scalding
- rubber ring most
- hot knife; also used commonly
- sharp knife 3%
- left to 3rd palpable joint; should cover anus/ vulva
- cut should be one clean pass
lamb marking; mulesing
- removal of wool bearing skin from tail/ breech
- reduce risk of flystrike due to build up of feces/ urine
- common for merinos
- aim is to remove skin only; facia should remain intact
-national mulesing accreditation program provides training
weaning
- management of growing lambs and allows ewes to recover before rebreeding
- around 12 weeks old
- at weaning lambs receive booster vaccine and general health check
- lambs often provided a ration before weaning (imprint feeding)
shearing
- typically shorn one annually or once every 6 months
- timing depends on sheep condition, season, weather, and wool parameters
- meat sheep still need shearing
crutching
- removal of wool from breech area
- reduce risk of flystrike due to build up of feces/ urine
- if annual shearing crutching occurs 6 months behind
- timed to coincide w high flystrike risk periods
- may also include removal of wool form face, underside and prepuce
jetting, dipping and backlining
- jetting; high pressure application, longer wool
- dipping; submersion, longer wool
- backlining; applied along back, immediately after shearing
all topical insecticides for lice and flystrike
drenching
oral anthelmintic for worm treatment, dose based on weight
drench resistance growing issue; need targeted drenching
annual vaccines
SQ injection in neck, protection against common diseases like clostridial and cheesy gland
- typically within 4 weeks of lambing for ewes or joining for ramns
foot care
- trimming and foot bathing in zinc sulphate
- treatment and prevention of foot pathologies and infection
- trimming often not required if sheep on pasture
paddock mating; how many rams to ewes
1-2% ramns
- joining lasts 5 weeks
- 90-95% of ewes may become preggo
when is preg scanning done
40-70 days post joining
done by scanning specialist not a vet
only 42% farms do this
wet/ drying
determining if ewes are rearing a lamb, have lambed and lost or had earlier preg loss, done by assessing udder, typically done at lamb marking
ewes who fail to rear lambs are culled
why husbandry important
welfare, productivity, cost of prevention vs loss
basic clinical exam; wool
- discolouration (often green= fleece rot)
- signs of skin irritation/ weeping
- signs of weak points in the wool
- lice
basic clinical exam; BCS
1-5, acceptable score will depend on context : sex, time of year, conditions
basic clinical exam; famacha/ fecal egg count
level of anaemia from barbers pole worm infection; under eye
- famacha; 1-5 where 1 is best
fecal egg count to assess worm burden
both are to help strategically drench
basic clinical exam; aging
- look at teeth, 1 pair per year
- 1 pair; 1 …. 4 pairs; 4 full mouth
- older they get more space in between teeth, missing/ broken teeth
basic clinical exam; udder
female breeding soundness exam
functional udder crucial for rearing lambs
basic clinical exam; male BSE
breeding soundness exam, perform 10 weeks before joining
basic clinical exam; feet
check outer horn, inner soft sole and interdigital space
between toes should be clean, dry and pink
nasty smell or discharge = trouble
temp and rainfall drive
- pasture availability/ quality
- which determines:
- when conditions are good for pregnancy
- stocky density and extensively or not
- also disease/ parasites rely on wet/humid and warm conditions
all of this means:
a calendar of operations will be specific to a sheep producing region
why is lamb timing important
want to match feed requirements of lambing ewes and pasture availability
when assessing health and determining disease risk always consider
- geographical region and environmental conditions
- time during calendar of operations
- age, sex, condition, breed of sheep
- experience of producer
worm and flystrike risk highest with
high rainfall and higher temps
sheep sight
excellent peripheral vision (prey species), but poor depth perception
sheep sound
excellent hearing, can direct ear towards sounds, disturbed by high pitched and loud noises
sheep smell
v sensitive sense of smell, can distinguish predators, receptive ewes and lambs, can locate water and particular feeds
sheep taste
less important, can play into feed selection
sheep touch
most sensitive on the nose and mouth (no long wool)
social behaviour
- very strong flocking (herding) behaviour (prey response)
- flocking instinct is breed dependent; merinos most gregarious
- too much pressure applied, one sheep will break away and others will follow
- sheep much more likely to follow others than move into empty space alone
- agitated if separated from the flock
- always move, handle and house sheep in groups where possible
- prefer their own breed
- vocal communication common
aggression
- domestication have favoured docility
- aggression typically between rams, but ewes can be aggressive if threatened
- more common during breeding season
aggressive behaviours
- snorting
- hoof stomping
- ramming (head to head, head to flank)
- pawing (flank)
play behaviours
- common in lambs, sometimes in adults
- play behaviours
- climbing
- trotting
- head tossing
- rearing
- bucking
what alert behaviour do they show
- turn, watch and listen, only return to grazing when they determine no threat
- mostly flight response, but sometimes defensive (ewes with lambs)
how often graze
- 8 hours a day at dawn/ dusk/ afternoon, sometimes overnight
- feeding bouts of 20-90mins up to 9x a day
describe they feed selection
discriminatory eating
when do lambs begin grazing
from 2 weeks
require ___kg DM per day
2-4
rumination
- will chew their cud
- regurgitation of consumed food to chew it further
- depends on diet, averages about 1/3 if day
- lag period between end of feeding and start of rumination
how often do lambs and adults sleep
lambs 8-12 h/day
adults 4 h/day
sleeping behaviour
- sleep in short naps
- middle of day
- resting at night= camping
- sternal recumbency
ram and ewe mating behaviour
ram; courting behaviours (sniffing, licking, pawing), flehman response, mounting
ewe; urination, standing to be mounted
birth behaviours
- ewes isolate, seek shelter
- restless
- ewe rapidly cleans lamb to remove membranes
- licking/ olfactory stimuli help bonding
in regards to maternal behaviours merino ewes often
mismother (9% singles, 15% twins, 24% triplets); head-butting, abandoning lambs
need minimum ___ sheep for normal flocking behaviour
4-5
sheep are good at hiding
pain
when assessing welfare look for absence of normal behaviours such as
- not eating
- isolation from flock
- no flight response
- physiological responses to pain
- elevated heart rate
- high cortisol
industry standard
typical procedures within an industry, the norm
guideline
suggestion of how procedures should ideally operate, typically made by experts
A SHOULD
standards aka legislation
acts, regulations; legal requirement for procedures, punishment for failure to follow, this is the law
A MUST
___ in 10 producers have NOT read the welfare standards/ guidelines; which means
4
vets must know it
some concerns around lamb marking
- invasive
- risk of infection and flystrike of open wounds
- short tail docking can lead to rectal prolapse and vulval cancer
- risk of disrupting maternal bond by separating ewes and lambs
- mulesing remains a highly political; likely to be driven out by consumers+ textile industry
pain relief requirements
- not required for lambs under 6 months except in Vic
- guidelines duggest pain relief where practical and cost effective
- pain relief is required if over 6 months in all states
pain relief products
- tri solfen, does not require prescription; post op spray; local anaesthetic+ antiseptic
- numOcaine; injected local anaesthetic
- meloxicam; pre op injected or oral NSAID
main reason why producers do not use pain relief
They don’t use pain relief because they don’t think they need to or they have never thought about it
in terms of pain relief important part of vets role is education of the client on things like
- The level of pain caused by procedures
- How pain can negatively impact production outcomes
- What pain relief is available and suitable
currently what percent of merino producers still muse
48%
age limits for mulesing
not less than 24 hours or over 12 months old
alternatives for mulesing
- Skin removal clips (closed technique)
selecting/ culling sheep based on breech cover, skin wrinkle, worm resistance and previous strike - Strategic use of chemicals, crutching and worm control
- Been trying to phase it out for 13 years
currently what percent of producers tail dock
95%
currently what percent of producers castrate males
98%
long distance transport concerns
- food and water restriction
- limited free movement
- ammonia build up
- high temps
- stress
for road transport strict requirements on
- time off water/ minimum spell
- loading density (based on weight)
- vehicle design to ensure airflow
- animals being fit to load
for live transport; new legislation since 2021 rules say
- no export during north hemisphere summer
- vessels must have appropriate ventilation and automated watering systems
- reduced notifiable mortality to 1% (from 2%)
- daily heat stress scoring
live transport strategies
- feed high fibre feed before transport to keep them full
- segregating different classes of sheep
- sheep should have shortest hair length possible
- BCS should be 2-4
- feedlot prep to introduce sheep to rations
drought concerns
- reduce food and water availability leading to
- starvation
- physical trauma
- ingestion of sand, dirt and poisonous plants
- increased disease spread and severity
- gut issues when feeding supplemental feed
strategies for minimizing poor welfare in drought
- reduce stocking numbers by destocking, agistment or euth
- minimize handling and travel for food and water
- provide supplementary feed, but introduce slowly
- eliminate competitors
- control worms, lice and flystrike; sheep in poor condition much more susceptible
- keep vaccinations up to date
- provide adequate, bog- proof water points
- monitor stock more regularly, intervene and euthanize animals as appropriate to avoid suffering
slaughter concerns
- sickness and injury following travel
- hunger/ thirst during lairage
- stress due to mixing w diff animals, rough handling, unfamiliar environment
- distress associated w seeing/ hearing/ smelling fear, pain and euth of other animals
- pain and suffering during euth
ethical concerns about killing animals for consumption are separate to
welfare concerns
slaughter: strategies for humane slaughter
- animals monitored and treated or humanely euthanized if sick or injured
- avoid lairage if possible, otherwise provide water (always) and food if over 24 hours
- avoid mixing unfamiliar animals, minimize time to slaughter
- good facility design
- low stock handling
- sheep made unconscious by electrical stunning or captive bolt prior to bleed out
legislation is all
state based and standards are not always laws
