Sheep Husbandry Flashcards
(EXAM) What is the difference in grazing behaviour between goats and sheep?
Goats browse more than sheep and select more digestible grasses
(EXAM) Which breed of sheep is considered most suitable for lamb meet production in a semi-arid region of Australia
Dorper
(EXAM) Which breed of sheep is characterized by a pearly white fleece with well defined crimp and little to no pigmentation of the skin?
Saxon Merino
(EXAM) The term “prime-lamb” is best described as
Lambs produced by mating a meat-type ram with a first-cross ewe
(EXAM) The lamb meat industry has met the international demand for larger and leaner lambs mainly by?
Increasing age at slaughter and using a larger mature-size to reduce fatness at a particular weight
(EXAM) What does a typical sheep-management calendar look like?
Ewes should be shorn in the month before expected lambing so that they are more likely to lead their own newborn lambs to shelter in the event of cold weather at lambing
Teeth Numbers for sheep
Number of teeth / 2 = age (yrs) Desciduous teeth = 0-1yr 2 teeth = 1 yr 4 teeth = 2 yr 6 teeth = 3 yr Full mouth = 4 yr
(EXAM) Two permanent incisors in a sheep’s mouth indicated that?
A ewe is old enough to join
(EXAM) List and describe 2 main differences between the biology of primary and secondary wool producing follicles.
How has selective breeding modified the biology to produce the modern merino compared to primitive breeds of sheep?
Primary: Hair like, arranged in trio-groups, sweat gland (suderiferous gland), erector pili muscle, wax gland (subaceous gland)
Secondary: Produce finest wool, arranged in trio-groups, DO NOT HAVE 1) sweat or wax gland
Selective breeding:
- Primitive sheep: More hairy fleeces
- Selective breeding for more Secondary fibres
- Move away from fat rolls to prevent fly-strike
- Move away from fleece on head
(EXAM) Describe how the manipulation of genetics of a prime-lamb producing flock might 1) reduce the risk of disease ; 2) Improve sheep productivity
Male: meat producing x with female 1st cross ewe increases genetic pool of lamb –> genetically more able to fight off diseases
More genetics = more productivity
Prime lamb flock: 2 lambings per year (Autumn and spring)
Joining
- Feeding ewes 6 weeks before mating to try and produce twins/triplets
- Correlation between BCS and mating/offspring
- Supplement rams = increased BCS, increased testes, increased sperm count, higher preg. rates
How does crutching differ from mulesing?
Crutching: Removal of wool around the tail/bottom for hygeinic purposes but does not contain cutting of skin
Mulesing: Cutting of skin and removal of hair follicles around anal region to prevent fly-strike
Weaning age and husbandry considerations
- Weaned at 4 months of age (earlier if feed shortage)
- Drench young and put in new pasture free of worms
- Apply cobalt, selenium, or copper bullets (via oral pill) which goes into rumen and works against nutrient deficiencies
Lamb marking
- Procedure of earmarking, castration, tail-docking, mulesing, and vaccination
- Lamb marked as a % of ewes joined
- Higher % = more profitable the farm due to amount they can sell
Sources of reproductive wastage (5)
1) Failure to conceive
2) Ovulation rate
3) Mismothering complex
4) Predation
5) Importance of birth weight
5-1 or 6-1 vaccine against which diseases
When to vaccinate
- Lambs vacc. at weaning time - Booster shot 6 weeks later
- Vacc. final month of pregnancy
5-1 (Blackleg, tetanus, malignant oedema, black disease, enterotoxaemia)
6-1 (same as above + Cheesy gland vaccination)
What is the time-frame between crutching and shearing?
6 months
At what age does joining occur? And why does it take this long?
6-8 weeks
Corresponds to 2 cycles of Ewe’s
Gestation length of sheep
148 days
At what age does weaning occur?
3-4 months
Cyclicity of pasture in Southern Australia versus Northern Australia
Southern: Peak pasture Sept-Dec
- Less cyclisity
- Lambing in May-Sept
Northern: Peak pasture Sept-Dec
- High cyclisity
- Lambing in Sept-Dec
Breech
The back end of the sheep including the tail, perineum and to the top of the back legs
Scoured wool
The amount of moisture present in the wool, as a percentage of the clean dry weight
Cotted
Wool which has become felted while on the sheep
Crimp
The natural wave of formation visible in wool.
The closer together the waves the finer the wool.
Used to be the measuring system - now replaced by micron measures.
Fine wool
Wool of mean fibre diameter less than 19 microns
Fly strike
The development of blow-fly larvae (maggots) on the skin of the live sheep
Gummy
Aged sheep that has lost its incisor teeth
Hagget
A young sheep of either sex just prior to the eruption of incisor teeth
Peppin Merino
The genetic name given to the common strain of medium wool producing merinos
Saxon Merino
The genetic name given to the common strain of fine wool producing merino’s
South Australian Merino
A recognized strain of strong wool merino sheep
Four major strains of Merinos (4)
1) Spanish (bare legs)
2) Sexon (Finest - greatest coverage)
3) Peppin (crossed in larger more robust)
4) South australian (crossed in larger more robust breeds)
Three common internal parasites in sheep
1) Fasciola
2) Barbers pole worm
3) Black scour worm
Four factors which influence the distribution of sheep
1) Rainfall/temperature/humidity
2) Water availability
3) Predators
4) Competition from other non-sheep enterprises
Three distinct zones where sheep are present in australia
1) High rainfall zone
2) Wheat-sheep zone
3) Pastoral zone
High rainfall zone
- Adjacent to coast
- 80% fine wool merinos and prime lamb
- Corriedales and Polwarths popular
- High production/management costs due to disease
- Good pasture growth
Wheat-sheep zone
- Highest density of sheep
- Strong and medium wool merinos
- Carry capacity 8x larger than pastoral zone
- Dry periods and cropping help break disease cycle
Pastoral zone
- Minimal rainfall
- 8-20% of sheep population
- Nearly all Strong Merinos
- Pasture growth season <5months
Which agricultural export is worth the most to australia?
a) Lamb
b) Live cattle
c) Live sheep
d) Mutton
e) Wool
Wool
2.322 Billion dollars per year
What are the main price drivers in wool? (6)
1) Mean fibre diameter
2) Fibre diameter coefficient of variation
3) Length
4) Strength
5) Vegetable matter
6 Colour
What are the unique properties of wool?
1) Extruded cells made of keratin
2) Long shelf life
3) Elasticity/durability
4) Hygroscopic - ability to absorb water
5) Weaving powers
6) Takes dyes readily
