SHEEP MANAGEMENT AND PRODUCTION

History of Merino sheep in Australia

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1 7 9 7A U S TR A L IA

1 7 9 0S O U TH A F R IC A

1 7 9 2E N G L A N D

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S P A IN

Present day industry

• The Merino sheep predominate accounting for over 75% of Australia's sheep population.

• The majority of the remainder of the flock is comprised of crossbreeds which are the result of crossing breeds of British origin with Merinos.

• In meat production the crossbreds produce heavier live weights but much coarser wool.

Present day industry

• Australasian breeds such as Corriedale and Polwarth evolved from crossing Merinos with British Breeds.

• The most common cross breed is the 1st Cross ewe which is a cross between a Merino ewe and a Border Leister ram

• These breeds combine the desired attributes of both wool and meat.

Present day industry

• Approximately 40% of the sheep population is in NSW with Western Australia being second with just under 20%.

• The sheep population is highest in areas that receive over 375mm of rain per year.

( MICRON) AVERAGE COST OF PRODUCTION

( 4 YEAR AVERAGE) AVERAGE PRICE RECEIVED

( 4 YEAR 1996-2000 INDICATOR) DIFFERENCE

21.6 - 22.5 $ 5.32 $ 5.91 $ 0.59

20.6 - 21.5 $ 5.91 $ 6.49 $ 0.58

19.6 - 21.5 $ 6.23 $ 7.56 $ 1.23

18.6 – 19.5 $ 6.78 $ 9.46 $ 2.68

17.5 – 18.5 $ 8.72 $ 12.06 $ 3.34

Merino Sheep

• There are 4 strains of Merino Sheep• Superfine ( Saxony)

• Fine

• Medium (Peppin)

• Strong (South Australian)

Super Fine Wool Merino• Climate and Geographical location

– High rainfall cooler areas eg NSW Tablelands and Tasmanian midlands.

• Micron– 14-16

• Wool Length– 65-70mm

• Farming Objective– Production of ultra-fine micron wool.

Fine Wool Merino• Climate and Geographical location

– High rainfall cooler areas eg NSW Tablelands and Tasmanian midlands.

• Micron– 16-18

• Wool Length– 70-75mm

• Farming Objective– Production of fine fibre diameter wool.

Medium Wool Merino• Climate and Geographical location

– Drier hot inland pastoral areas of NSW, QLD and WA.

• Micron– 18-22

• Wool Length– 80-90mm

• Farming Objective– Production of general purpose apparel fibre.

MEDIUM WOOL MERINO

Strong Wool Merino• Climate and Geographical location

– Low rainfall and hot semi-arid regions of Australia

• Micron– 23-25

• Wool Length– 100-105mm

• Farming Objective– Production of a general purpose fibre with a high

fleece weight.

• DUAL PURPOSE SHEEP

Corriedale• Climate and Geographical location

– Most grazing areas of Australia with high rainfall and improved pastures

• Micron– 27-30

• Wool Length– 140-150mm

• Farming Objective– Production of prime lambs and wool

CORRIEDALE RAMS

Polwarth• Climate and Geographical location

– Cool , high rainfall areas with improved pastures

• Micron– 23-25

• Wool Length– 100-105mm

• Farming Objective– Production of prime lambs and wool

BRITISH BREEDS OF SHEEP

• The united Kingdom is renowned for its many different breeds of sheep. Most of them are bred in cooler climates with high quality pastures.

• British breed sheep are used mainly for crossing with Merinos to produce prime lamb mothers or prime lambs.

• British breed sheep are dived into two types– Longwooled– Shortwooled

LONG WOOLED SHEEP• These sheep get their name from the length of

their wool. It can grow between 175mm and 300mm per year.

• The wool is coarse with a broad crimp.• They usually have black hooves and nostrils

and white faces and legs.• They are hornless with a large frame.• They are very good mothers and are crossed

with Merinos to produce prime lamb mothers.

BORDER LEICESTER RAM

SHORT WOOLED SHEEP

• The short wooled sheep have a short, harsh, chalky white coloured wool.

• They have a compact body with high degree of muscling and as such produce high quality meat.

• The shortwooled sheep are used to cross with most commonly 1st Cross ewes ( Merino x Border Leicester) to produce prime lambs.

POLL DORSET RAM

WHITE SUFFOLK RAMS

TEXEL RAM

SOUTH SUFFOLK RAMS

PRIME LAMB PRODUCTION

• Prime lambs are produced for the meat market. There are two types of prime lamb– 1st Cross– 2nd cross

1st Cross Lambs

• This type of lamb is found in the more marginal rainfall areas. They are a cross between a long wooled British breed usually Border Leicester and a Merino.

1st Cross Lambs

• This lamb is better than both parents (hybrid vigour), grows quickly and matures fast.

• The best 1st cross ewe lambs are kept and used to produce 2nd cross lambs, these ewes are excellent mothers with high fertility often having twins and even triplets.

2nd Cross Lambs• This type of lamb is found in the high

rainfall areas where pasture production is high.

• They are the progeny of a 1st cross ewe and a short wooled British breed such as Poll Dorset.

• They have a very high growth rates with lambs often reaching 25kg within 18-20 weeks of birth.

2nd Cross Lambs

• These lambs show a high degree of hybrid vigour, where the progeny are better than both parents put together.

• All 2nd cross lambs are slaughtered for meat.

2ND CROSS PRIME LAMB

Breeding a 2nd Cross Lamb

S o ld fo r s lau g h te r

R am L am b s

A ll so ld fo r s lau g h te r

2 n d c ross L am b

Is t C ross E w e S h ort w oo led ram

B es t kep t fo r b reed in g C u lls so ld fo r s lau g h te r

E w e L am b s

1 s t C ross lam b

M erin o E w e B ord er L e ices te r R am

LAMB MARKING• Lamb marking is the name given to 3

operations done at the same time. The operations are ear marking, tail docking and castration of male lambs.

• At marking lambs are usually vaccinated with 6 in 1 vaccine.

• Lambs are usually marked between 2 and 8 weeks of age. The younger lambs are marked the less stress and risk of infection occurring.

LAMB MARKING• Castration

– This is the removal or destroying of the testes of male lambs.

– It is performed either with a knife or an elastrator.

– When a knife is used the end of the scrotum is cut off and the testes are pulled out with a hook on the end of the knife or your teeth.

– The elastrator uses a rubber ring which is placed above the testes which stops the flow of blood to the testes and they wither and fall off.

LAMB MARKING

LAMB MARKING• Earmarking

– Earmarks are registered by the owner of the sheep. They are a combination of slashes, blocks and v’s that are cut out of the ear. The pliers cut away the ear and leave a permanent mark.

– In NSW the registered ear mark is applied in the right ear of ewes and left ear of males ( females are always right).

– Age marks and ear tags are put in the opposite ear.

DOCKING

• Docking is the cutting off of the tail. The place where the tail is docked is very important.– to long and the sheep will get flystrike as the tail

will get covered in manure.– to short and the anus and vulva become sunburnt

and skin cancer can result.– The recommended place is at the second joint, or

at the tip of the vulva

DOCKING• Tail docking can be done with a knife

elastrators or a hot knife.• When using a knife the cut needs to be made

quickly by pushing down on the knife and pulling forward the tail

• When using elastrators the ring is placed at the correct point and left to allow the tail to drop off.

• The hot knife cuts the tail but also seals the blood vessels to stop the bleeding.

ELASTRATORS

MULESING

• Mulesing is the practice of the removal of the folds of skin from the breech area of sheep to reduce flystrike.

• The skin folds would normally become stained with urine and manure allowing flystrike to occur.

• The skin is removed using a pair of mulesing shears which have a curved blade.

MULESING

VACCINATION• Vaccination is the injecting of a part or whole of

a pathogenic organism to build up resistance or immunity to the disease.

• The most common vaccination given to sheep is a 6 in 1 which controls– Pulpy Kidney– Black leg– Black disease– Enterotoxaemia– Tetanus– Cheesy Gland

VACCINATION

• Other pathogens that are commonly vaccinated against are:-– scabby mouth– vibriosis– sheath rot ( testosterone injection)

Sheep Vaccinating

Sheep Vaccinating

REPRODUCTION• In sexual reproduction one sperm from a

male unites with an ovum from a female. This is called fertilisation.

• The main reproductive organs of a male are the testes in which sperm and testosterone are produced.

• The testes lie outside the body in the scrotum which regulates the temperature of the testes keeping them below body temperature.

REPRODUCTION• If the testes become to hot or to cold sperm

begins to die causing the rams to be infertile.

• Once the sperm has been produced it matures in the epididymis at the base of the testes.

• When the ram goes to mate the sperm travels up the vas deferens to the seminal vesicles, cowper's gland and prostate gland where a number of fluids are added.

Rams Testicle

REPRODUCTION• The mixture of sperm and other fluids is called

semen.

• The role of the fluids is to– provide a medium for the sperm to swim in– provide a nutrient source for the sperm– neutralise the reproductive tract of the female which

is slightly acidic.

• The semen than travels down the urethra through the penis where it is placed inside the female reproductive tract. This process is called ejaculation.

SPERM

REPRODUCTION• The main reproductive organs of the female are

the ovaries.

• The ovaries produce ova which in sheep are released about every 18 days in a process called ovulation.

• The released ova then travels down the fallopian tubes where if mating has occurred fertilisation normally takes place.

• If fertilisation has occurred the ova moves down to the uterus where it implants to the wall and begins to develop into a foetus.

REPRODUCTIVE SYSTEM FEMALE

REPRODUCTION• If fertilisation has not occurred the ova will be

absorbed into the blood stream of the ewe and ovulation will occur again about 7 days latter.

• If fertilisation has occurred the foetus will develop in the uterus for approximately 5 months.

• Just before birth the female will release a number of hormones which will relax the walls of the cervix and vagina and cause the uterus to begin to contract enabling the lamb to be born.

ReproductionPuberty.

• The first step in the reproductive cycle is reaching puberty.Puberty is the age at which the young animals reproductive organs become functional.

• In females the release of ova from the ovaries and in males the production of sperm by the testes

Reproduction

• The age of puberty is generally determined by the weight of the animal.

• Although an animal may become pregnant after reaching puberty, sexual maturity is not reached until some time later.

Reproduction Physiology

The Oestrus Cycle• The oestrus cycle is the breeding cycle of

females, each oestrus cycle consists of a period of sexual activity followed by a period of sexual inactivity.

• The female will only allow the male to mate with her for a short time period each cycle. At this time the female is said to be in oestrus or on heat.

Reproductive characteristicsof common farm animals

Animal Onset ofpuberty(months)

Gestationperiod(days)

Length ofoestrus cycle(days)

Length ofoestrus orheat (hours)

Doe 4-8 150 20 36

Ewe 6-12 147 17 30

Sow 4-9 114 21 48

Cow 6-18 280 21 18

Mare 10-24 336 21 144

RUMINANT DIGESTIVE SYSTEM

Position of Digestive system

DIGESTIVE SYSTEM

RUMINANT DIGESTIVE SYSTEM

Ruminants have four stomachs

• RUMEN

• RETICULUM

• OMASUM

• ABOMASUM

The Rumen

Rumen

• The rumen is the first stomach of the ruminant animal.

• It is a very large sac containing millions of microorganisms that break down the cellulose of plant material.

The Reticulum

Reticulum

• The microorganisms secret enzymes which attack the food and break it down so the animal can use it.

• The microorganisms also

- produce B vitamins

- improve the ability for the animal to digest protein in the food.

The Omasum

Omasum

• The omasum or bible is the third stomach of the ruminant animal.

• The omasum removes 60% to 70% of the liquid from the reticulum.

• The omasum is made up of page like leaves with a rough surface which grind the food into a very fine paste.

The Abomasum

ABOMASUM

• The ABOMASUM or true stomach is the 4th stomach of the ruminant.

• Cells in walls secrete gastric juices which starts the digestion of protein.

• Gastric juices also contain HCl which kill the majority of rumen microbes.

Ruminant Digestive SystemAdvantages

• Digest cellulose

• Upgrade low quality feedstuffs

• Make protein from urea and other non-protein nitrogen (NPN) sources

• Produce its own vitamin B from microbial sources.

SMALL INTESTINE.

• Simple sugars , amino acids and minerals are absorbed through the villi which line the mucus membrane of the small intestine.

• Capillaries move the digested material to the liver where it is stored mainly in the form of glycogen until it is circulated around the body.

LARGE INTESTINE.

• The large intestine removes a large percentage of the water in the food which becomes concentrated.

• A small amount of microbial breakdown of the food occurs in the large intestine.

• The waste material is stored in the rectum before it is expelled through the anus as faeces.

Sheep blowflySheep blowfly

Sheep blowflySheep blowfly Most flystrike is caused by the Australian sheep

blowfly, Lucilia cuprina. Development of the sheep blowfly, Lucilia cuprina, is

temperature-dependent, with warm temperatures favouring rapid growth.

Eggs are laid on susceptible sheep. Lucilia cuprina breeds almost exclusively on living sheep. Wet, fleece-rotted sheep are susceptible to bodystrike. Young sheep are most at risk. Fleece rot is especially severe in sheep which have been thoroughly wet twice. Sheep with lumpy wool, foot rot, scours, injuries and lambing stain are also at risk. Eggs hatch after about 11 hours.

Common blowflies that strike Common blowflies that strike sheep in sheep in

NSWNSW90+% of strikes

Sheep blowflySheep blowfly• Newly-hatched maggots feed in damp, rotted fleece.

Maggots moult twice while feeding on weeping skin surface. After about 4 days, fully-fed maggots drop from

sheep - usually at night - and burrow into soil. • Adult flies live for only 2-3 weeks. But, if protein

resources are available, females may lay several egg batches.

Sheep blowfly life cycleSheep blowfly life cycle

Sheep blowflySheep blowfly• CONTROLLING BLOWFLIES

• Non-chemical controls Shearing and crutching. Selection of replacement rams resistant to body strike. Culling hoggets which are susceptible to body strike. Culling adult sheep which may have to be treated for

strike. Flytraps. Mulesing.

TREATING STRUCK SHEEPTREATING STRUCK SHEEPShear struck wool and a 50 mm barrier of clean wool around the strike, close to the skin to remove maggots

Apply a registered flystrike dressing to the shorn area to prevent restrike

Collect the maggot-infested wool into a maggot-proof (plastic) bag to kill all maggots. This breaks the life cycle.

If necessary, sheep treated as outlined above can then be jetted along with other susceptible sheep.

Remove struck sheep from the mob.

HAND JETTINGHAND JETTINGOnly jet susceptible sheep (weaners)Only jet susceptible sheep (weaners)

Use a Dutjet, particularly for longer woolUse a Dutjet, particularly for longer wool

Fit a pressure gauge at the Fit a pressure gauge at the handpiece. Jet at 600kPa (100psi)handpiece. Jet at 600kPa (100psi)

Follow the label instructions for Follow the label instructions for insecticide dilutioninsecticide dilution