Transcript Sheep - 1

Sheep - 1
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In this unit you will learn about...
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Breeds of Sheep and their characteristics.
Dental Formula.
Target weights.
Gestation Period and Oestrous cycle (duration & length).
Ram & Ewe Selection.
Mixed Grazing.
Creep Feeding.
Breeding Management Programme- Flushing & Sponging
Management of the pregnant ewe.
Management of lamb from birth to slaughter.
Sheep Dipping and shearing.
Sheep Housing.
Wool.
 Lamb
weighs
• 3 –5 kg at birth
• 30-40kg at slaughter
 Gestation
period 149 days (5 Months)
 Oestrous cycle 17 days
 Duration of oestrous 36 hours
 Ruminant
 Phylum Chordata
 Even Toe Ungulates
 Incisors,
Canines, Premolars, Molars.
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4033
X2
 Growth
 Tillering-
rates increase by 10-15%
a denser sward & increased DM
production
 Flush of grass around dung is ate by sheep. This
is unpalatable to cattle.
 Even recycling of nutrients
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State the length and duration of the oestrous
cycle.
What is length of gestation?
Name the phylum that sheep belong to.
State the dental formula foe a sheep.
What is mixed farming?
Give the advantages of mixed grazing.
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Mountain & Lowland Breeds.
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Wool/Lamb/Ewe Production
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Degree of prolificy – 1,2,3
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Growth rate & Conformation
• Blackface Mountain
• Wicklow Cheviot
• Galway
• Suffolk Down
• The Belclare Improver
 Prolific
breeds- Belclare Improver
 Carcass
breeds- Suffolk, Texel
 Cross
 Ewe
breeds:
breeds- Galway, Blackface Mountain and
Cheviot.
 Mountain
Breed
 Ewe Breed
 Small & Hardy
 Able to withstand
mountain conditions
 Horned
 Wool & breeding ewes
 Become prolific if
crossed appropriately.
 Mountains over 350m
Kerry, Galway, Donegal,
etc
 Mountain
Breed
 Small
 Not
as hardy as blackface
 Able to withstand
mountain conditions
 Wool & breeding ewes for
lowland fattening.
 Mountains Wicklow,
Carlow, Kildare, Wexford
 Lowland
 Native
breed
 Live in a less severe
environment
 Big & Late maturing
 Wool, Fat lambs & hogget
mutton & breeding ewes
Suffolk
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 Cross
between Galway & Finnish Landrace –to
improve prolificy
 X & Llynn –to improve conformation
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Name 3 categories of breeds.
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Name 4 breeds.
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Give their characteristics.
 If
flock is inadequate or poor quality –Replace
either ewes or RAMS- Cheaper to replace
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RAM = 50 Ewes naturally
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RAM = 8/10 ewes Synchronisation
 Good
Carcass
 Good Conformation
 Good prolificy.
 Wool/ewes/meat
 Feed: fertility is increased with high quality feed
 EWE
 Good
 RAM
Conformation
 Good
 Good General Health
Conformation
 Daughter of Prolific Mother
 Good General
 Free from hereditary defects
Health
 Good Feet
 Performance
Tested by dept.
 Very Good Feet
 Pure
breed
 If ram has been used the previous year and ewe
labs retained –Ram has to go!!!!!
 Insure not Sterile,
 Ram reaches puberty at 6 months
 Ram
is half the flock.
• Growth rate
• Conformation
• Killing out %
• Leaness
 All
are determined by
the RAM breed
(purebred/pedigree)
Pedigree Texel Ram realised
220,000 Guineas Sept 2009
 Ewe
should be prolific
 Good mothering qualities.
 Flushing of ewe increases number of lambs.
 Reproductive efficiency.
 Belclare Improver
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Old.
Not prolific.
Udder troubles (mastitis)
Faulty teeth.
Under size.
Lambing difficulties.
Low milk yield.
Barren.
Bad feet.
 List
5 factors to be considered when selecting
breeds.
 Name the factors when selecting ewes and
rams.
 Consider the comment that “rams are for
quality and ewes are for quantity”.
 When is it time to consider replacing the ewe?
 Seasonally
Polyoestrous
 Oestrous Sept-Feb
 Length 17 days
 Duration 36 hours
 Gestation Period 149 days (5 Months)
 Sheep
are seasonally polyoestrous.
• This means they come into oestrous repeatedly but
only over a certain period or season of the year.
• This period is from early September to February
• The length of oestrous is 17 days
• The average duration of oestrous is 36 hours
 The
declining light levels in September act on
pituitary gland.
 This stimulates Follicle stimulating hormone
(FSH)
 This in turn stimulates the ovaries to produce
oestrogen
 This begins the oestrous cycle.
 Ewes
should be in good condition – Condition
Score = 3.5-4.0
 High Conception rate results
 Technique = Flushing
 Moving sheep onto rich pastures 2 weeks
prior to mating
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Two weeks before mating the sheep should
receive their winter dip (not before 15th
September)
Otherwise the sheep can receive the dip a few
weeks after mating.
The whole flock should be dosed for
intestinal parasites (worms).
The wool around the tail should be trimmed
to facilitate service and avoid injury to the
ram.
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Ewes are stocked heavily on bare pastures
25/30/ha before weaning & mating
A couple of weeks before mating nutrition is
improved by stocking them less heavily 15/18/ha
More eggs released at ovulation (twins)
More regular heat periods
Higher conception rates
Better attachment to uterus
 Ewe:ram
1:40
 Ewe:ram 1:10
 Rams must be kept away as they will fight
 Dates kept = lambing date
 Marker dye –every 17 days- Raddled
 Ear tagged
 6-8 wks- all should be in lamb
 Suspect ram-cull
 This
is a technique used to induce ewes to lamb
early enough for the lambs to be ready for the
Easter market
 Prices are highest at this time
 Lambs born from September/October matings
will not be ready for the easter market.
 Ewes must be brought into oestrous out of
season, in July or August.
 This
involves placement of the progesterone-
impregnated sponges.
 When
the sponge is removed a single
intramuscular injection of pregnant mares
serum gonadotrophin (PMSG) is
administered to the sheep.
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Ewes are introduced to the ram in early Sept. for 8 weeks
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Heat & served at different times- lambing protracted
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Oestrous can be synchronised. Shorter mating & lambing
periods
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Sponges are impregnated with progesterone into the ewes
vagina & left their for 12 –16 days.
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The progesterone blocks the oestrous cycle
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If sponges are removed simultaneously all ewes come in
oestrus 2 days later & are all mated together
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All lambs born same time (not protracted)
 Detects
mating behaviour in rams.
 Helps predict lambing date.
 Aids in detecting infertile ewes which is therefore
useful for culling.
 Also identifies infertile ram. (if all ewes show 3
different colours).
 Colour changes every 17 days.
Explain the following terms:
1.
Synchronisation.
2. Flushing
3. Sponging
4. Breeding out of season.
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Outline the steps involved in preparing the
flock for mating.
What is a raddling harness?