leaving certificate agricultural science
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Leaving Certificate Agricultural Science. Sheep - 1. Learning Outcomes. In this unit you will learn about... Breeds of Sheep and their characteristics. Dental Formula. Target weights. Gestation Period and Oestrous cycle (duration & length). Ram & Ewe Selection. Mixed Grazing. - PowerPoint PPT PresentationTRANSCRIPT
Sheep - 1
In this unit you will learn about...• 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.
0 0 3 34 0 3 3
X 2
Growth rates increase by 10-15%
Tillering- a denser sward & increased DM production
Flush of grass around dung is ate by sheep. This is unpalatable to cattle.
Even recycling of nutrients
1. State the length and duration of the oestrous cycle.
2. What is length of gestation?3. Name the phylum that sheep belong to.4. State the dental formula foe a sheep.5. What is mixed farming?6. Give the advantages of mixed grazing.
Mountain & Lowland Breeds. Wool/Lamb/Ewe Production Degree of prolificy – 1,2,3 Growth rate & Conformation
• Blackface Mountain• Wicklow Cheviot• Galway• Suffolk Down• The Belclare Improver
Prolific breeds- Belclare Improver Carcass breeds- Suffolk, Texel Cross breeds: Ewe 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
12Suffolk
Cross between Galway & Finnish Landrace –to improve prolificy
X & Llynn –to improve conformation
1. Name 3 categories of breeds.2. Name 4 breeds.3. Give their characteristics.
If flock is inadequate or poor quality –Replace either ewes or RAMS- Cheaper to replace
1 RAM = 50 Ewes naturally 1 RAM = 8/10 ewes Synchronisation
Good Carcass Good Conformation Good prolificy. Wool/ewes/meat Feed: fertility is increased with high
quality feed
EWE Good Conformation Good General Health Daughter of Prolific Mother Free from hereditary defects Good Feet
RAM Good
Conformation Good General
Health 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
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
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.
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.
Ewes are introduced to the ram in early Sept. for 8 weeks Heat & served at different times- lambing protracted Oestrous can be synchronised. Shorter mating & lambing
periods Sponges are impregnated with progesterone into the
ewes vagina & left their for 12 –16 days. The progesterone blocks the oestrous cycle If sponges are removed simultaneously all ewes come in
oestrus 2 days later & are all mated together 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.
1. Explain the following terms:1. Synchronisation.2. Flushing3. Sponging4. Breeding out of season.
2. Outline the steps involved in preparing the flock for mating.
3. What is a raddling harness?