1. Leaving Certificate Agricultural Science
Sheep

2. 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.
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.

3. Sheep Facts Lamb weighs Gestation period 149 days (5 Months)
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

4. DENTAL FORMULA- Sheep
Incisors, Canines, Premolars, Molars.
X 2

5. Sheep production in Ireland
2 main types of sheep production systems in Ireland
Lowland sheep production (which we will study in detail)
Mountain/Hill production

6. Comparing Mountain/Hill and Lowland sheep production
Extensive farming
Intensive farming
Low production targets
High production targets
Rough grazing
Rotational grazing
Ewes generally have only one lamb
More ewes give birth to twins and triplets
Sheep breeds used are suited to exposed conditions
Larger, muscular sheep used to produce meat

7. Stages in the life of sheep
Name
Age
Sex
Stage
Lamb
Up to 6 months
Male/Female
Newborn
Hogget
7 – 8 months
Sheep in their 2nd calendar year
Ewe
From 1 year on
Female
Has at least one lamb
Ram
From 8 months
Male
Mature male
Wether
From 1 week old
Castrated male
Store
From 3 months old
Needing a certain time to finish

8. Breeds of sheep

9. Blackface Mountain Mountain Breed Low size and bodyweight
Small & Hardy
Very good mothers
Horned
Wool & breeding ewes
Mostly single lambs but can become prolific if crossed appropriately.
Mountains over 350m Kerry, Galway, Donegal, etc

10. Wicklow Cheviot Mountain breed but more suited to fertile hills
White face and legs and good quality wool
Not as hardy as blackface nut are able to withstand mountain conditions
Good mothers that mainly have single lambs
Mountains Wicklow, Carlow, Kildare, Wexford

11. Galway Lowland breed Native breed of Galway and Roscommon
Very good wool production
Very large size & body weight
Late maturing and late finishing

12. Suffolk Lowland breed Distinctive black head and black legs
Conformation breed (good body shape)
Good wool production
High prolific breed

13. Suffolk

14. Texel Lowland breed White faced breed Good conformation
Early maturing and finishing
Produces lean meat
Good prolificy

15. The Belclare Improver Lowland breed Maternal breed of medium size
Early maturing
Polled and white in colour
Produces high no of twin lambs

16. Learning check... Name 3 categories of breeds. Name 4 breeds.
Give their characteristics.

17. Selecting Breeds Good Carcass Good Conformation Good prolificy.
Wool/ewes/meat
Feed: fertility is increased with high quality feed

18. Ewe & Ram Selection RAM EWE Good Conformation Good Conformation
Good General Health
Performance Tested by dept.
Very Good Feet
EWE
Good Conformation
Good General Health
Daughter of Prolific Mother
Free from hereditary defects
Good Feet

19. RAM Selection 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

20. Pedigree Texel Ram realised 220,000 Guineas Sept 2009
Ram for Quality
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

21. Ewe for Quantity Ewe should be prolific Good mothering qualities.
Flushing of ewe increases number of lambs (see later).
Reproductive efficiency.
Belclare Improver

22. Time to replace ewe if: Old. Not prolific. Udder troubles (mastitis)
Faulty teeth.
Under size.
Lambing difficulties.
Low milk yield.
Barren.
Bad feet.

23. Learning Check....
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?

24. Gestation (don’t write)
Seasonally Polyoestrous
Oestrous Sept-Feb
Length 17 days
Duration 36 hours
Gestation Period 149 days (5 Months)

25. Oestrous cycle 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
Gestation period is 149 days or 5 months

26. Oestrous cycle
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.

27. Preparing Stock For Mating
Ewes should be in good condition – Condition Score =
High Conception rate results
Technique = Flushing

28. Flushing
This involves placing ewes on a low plane of nutrition after weaning followed immediately by a high plane of nutrition 3 – 4 weeks before mating
Advantages
More eggs released at ovulation (twins)
More regular heat periods
Higher conception rates
Better attachment to uterus

29. Before 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.

30. Mating Ewe:ram 1:40 During mating Ewe:ram 1:10
Rams must be kept away as they will fight
Dates kept = lambing date
Marker dye or a raddle is used every 17 days
Ear tagged if paint is on ewe
6-8 wks- all should be in lamb
Suspect ram-cull

31. Breeding out of season
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.

32. Breeding out of season
This involves placement of the progesterone-impregnated sponges into birth canal of ewe for 12 – 16 days.
When the sponge is removed a single intramuscular injection of pregnant mares serum gonadotrophin (PMSG) is administered to the sheep.
Two days later, all ewes come into heat

33. Sponging Ewes are introduced to the ram in early Sept. for 8 weeks
Heat & served at different times- lambing protracted
Oestrous can be synchronised.
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)

34. Raddling Harness 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.

35. Learning Check.... Explain the following terms:
Synchronisation.
Flushing
Sponging
Breeding out of season.
Outline the steps involved in preparing the flock for mating.
What is a raddling harness?

50. Mixed Grazing of Cattle & Sheep
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

51. Learning Check... 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.