leaving certificate ag. science – sheep production sheep...

Leaving Certificate Ag. Science – Sheep Production

SShheeeepp PPrroodduuccttiioonn 1. Why are sheep profitable?

a. Can survive on both mountain and

lowland areas.

b. They can utilise herbage that other

animals cannot. E.g. Heather

c. They can climb to areas where other

animals cannot gain access.

On lowland farms where Cattle and Sheep are

grazed together meat output per hectare is

significantly higher than if they were grazed

separately. Why?

Because sheep can control weeds in pastures

as they graze herbage that cattle would not.

The EU is about 75% self-sufficient in sheep

meat.

The production of wool is an added

advantage


2. Classification of Sheep Breeds

The Old Means of Classification

Short Wool Breeds (Suffolk & Down Breeds)

Long Wool Breeds (Galway, Border

Leicester)

Hill & Mountain Breeds (Wicklow Cheviot,

Blackface Mountain.

The new method of classification is based on

Meat production rather than on wool. Why?

1. The Ewe Breeds – The female of these breeds

are able to produce good quality carcases

when crossed with a quality ram. Examples

include Galway, Blackface Mountain and the

Cheviot.

2. The Prolific Breeds - Ram breeds who give

significantly more offspring than the Galway or

other Ewe Breeds. Examples are the Border

Leicester, the Belclare Improver and the Blue

Faced Leicester.

3. The Carcase Breeds - include the Suffolk,

Down Breeds and the Texel. These are again


Ram Breeds, which impart superior carcase

qualities on their offspring. They are also known

as TERMINAL SIRES.

4. The Cross Breeds – Do not include mongrels.

The result of systemised cross breeding policies

to produce offspring baring all the best

qualities. They usually involve a prolific sire and

an indigenous (normal) ewe.

Examples:

Blackface x Border Leicester = Greyface

Blackface x Blue faced Leicester = Mule

Cheviot x Border Leicester = Half-breed

Galway x Belclare Improver = Improved Galway

3. The Main Sheep Breeds

A. The Galway

Big, Late maturing Long Wool Sheep.

Pure breed Galways are sold for Store

Production as HOGGETS between Xmas and

Easter of their first year.


When crossed with Suffolk the offspring then

mature early. Crossed with Belclare Improver

to give ……………?

B. The Blackface Mountain

Also known as Scotch Blackface.

Are very Hardy and thrive in harsh & exposed

conditions.

Low lambing rate! Why?

When brought down to lowland farms,

Blackface ewes become prolific dams.


C. The Wicklow Cheviot

More so a hill breed and not quite as hardy as

the Blackface.

Usually crossed with a prolific breed for

production of commercial breeding ewes.

D. The Suffolk Down

Very popular ram for production of fat lambs.

Impart excellent carcase characteristics to

their offspring.

Important for early lamb production (born at

Xmas and sold at Easter)


E. The Texel

Originate from an island off the coast of

Holland.

Introduced to Ireland in the 1960’s and 70’s.

Low prolificacy but known better as a

TERMINAL SIRE.

Very low lean to fat percentage.

F. The Belclare Improver

New breed developed by Scientists in the AFT

Institute in Co. Galway.

Made up from three lines of breeds.

4. General Breeding Policies

What happens if you find that your flock are

inadequate and not good quality?

Do you replace them all?


Do you replace just the ewes?

It is cheaper and more effective to up-grade

your flock by replacing the rams gradually.

One ram can serve up to 50 ewes.

What does the average Irish farmer look for

when breeding sheep?

Most Irish breeds will produce a good carcase

in their lambs when crossed with a suitable sire

(ram) so…

The most important thing to considered is

prolificacy.

The rate of lambing or the number of lambs

weaned per ewe is the most important factor

when considering the profitability of sheep

production.

Every year the farmer should hope to up

grade a proportion of his / her ewes by

crossing with a prolific breed or else by

replacing them with a more prolific ewe.

The three way cross.


5. Targets for Sheep Production

The national meaning average is less than 100

(i.e. < 100 lambs weaned per 100 ewes).

Higher in lowland flocks and lower in the

mountain flocks (mainly in the West of the

country). On the eastern mountain flocks the

percentage is around 80%.

The realistic target for lowland flocks is 160

lambs weaned for every 100 ewes.

What will happen some of the lambs born?

Then we need a lambing rate of nearly 200%.

Since some the ewes in the flock will be

hoggets, all of the older ewes will be expected

to have twins or triplets.

6. Stock selection

Ewe Selection

From the existing flock ewes should be

replaced if they are not suitable for breeding.

These include:

Age


Udder troubles (Lumps, mastitis etc)

Faulty Incisors (teeth)

Under sized ewes.

Lambing difficulties and bad mothering

properties (low milk yield / rejection)

Barren ewes.

Bad feet.

These ewes should be replaced by daughters

of good mothers (hard to predict otherwise)

Do not use lambs in the flock that have been

sired by Suffolk or Texel. Why?

Prolific crosses should be given preference

when buying in lambs.

Ram Selection

The ram is half the flock when you think of

genetics so their selection is very important.

The ram should be pure bred and generally of

the same breed as the ewe (depends on the

use of the lambs).

The ram should be of a prolific or carcase

breed.


If the ram was used the previous year and the

ewe lambs are retained then he should be

changed. Why?

Otherwise his daughters should be joined or

served by another ram.

7. Flushing

Fertility of the ewes is greatly influenced by her

diet and nutritional state.

The ewe should be gaining weight up to and

during mating and should maintain this

condition while the ram is with the flock (six to

eight weeks)

This is achieved by Flushing.

Flushing constitutes moving the sheep onto rich

pasture two weeks prior to mating. Good after

- grass is very suitable for this.

If good grass is not available then

concentrates will be required.

Flushing affects fertility in a number of ways:


A. It increases ovary activity to result in more

heat periods.

B. It causes multiple ovulations (twins and

triplets)

Ewes that had lambs the previous year should

be “slimmed down” after weaning (Put on

poor pasture or densely stocked) Why?

If they are not reduced in this way then they

may be too fat at mating time or may not be

able to put on the weight during the critical

period.

8. 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.

All ewes should have their udders checked for

hardened lumps with serious cases being

culled.

The whole flock should be walked through a

FOOTBATH to prevent footrot trouble. Affected

animals should be properly taken care of.

Flushing two weeks before joined by the ram.

9. Mating

The ram should be in good forward condition

but not fat. Why?

Fatness reduces activity and fertility while poor

condition may leave him weak and

emaciated at the end of mating.

Rams should be raddled daily with a suitable

marker or a marker harness fitted. WHY?

A. So that served ewes can be separated.

B. To check for ram fertility i.e. repeat

services.


The rams may need to be hand fed as they

would generally not eat much during mating.

After mating (six to eight weeks) the ram is

removed from the ewes and placed in a

separate paddock with the other rams.

He must gain weight before the onset of winter.

Ewe Lambs

Ewe lambs can be served in their first year

provide the weigh 50kg at mating time.

It is advisable to put all the ewe lambs in one

paddock with a ram to themselves.

The ram should be mature and definitely not a

ram lamb.

10. After Mating

The foetus grows very slowly during the first

three months or pregnancy so the feed

requirements are generally low but good

feeding should be maintained for the first six

weeks.


The feeding over the next six weeks can be

reduced slightly

Look out for foot problems

Administer winter dip if not already carried out.

11. Late pregnancy

During the last two months of pregnancy, the

unborn foetus grows very rapidly and the

ewe’s udder development increases

accordingly before the onset of lambing.

Because of this growth and development, the

nutritional demands of the ewe increases also.

BUT there is a small problem. Because the

foetus is growing so rapidly inside the ewe,

there is little room available for the digestive

system of the sheep.

The answer is a more concentrated diet.

Fodder beet or turnips are useful or the use of

meals and nuts.


Six weeks before lambing, the meals should be

introduced, 250g a day at first and gradually

increased to 750g a day.

Ewes with twins should be fed more

accordingly.

There is a scanning technique to determine

whether or not a ewe is carrying twins.

What happens if ewes are under fed??

Serious problems occur if the ewe is underfed.

Twin lamb disease, which can prove fatal for

the ewe and lambs.

Too much feeding can also prove problematic.

How?

Over fat ewes can also develop twin lamb

syndrome and over feeding can also cause

the foetus to grow too quickly and cause

lambing problems.

Ideally, the ewe should be of good size and

have enough nutritional reserves (steaming up)

to ensure enough milk is available for her

lambs.


12. Before lambing

Two weeks before lambing the ewe receives a

“seven in one” or “eight in one” booster

injection against clostridial diseases.

The ewes should again dosed for intestinal

parasites (worms)

The wool around the tail should be removed or

trimmed. In addition the wool around the

udder should be trimmed.

13. Lambing

The gestation period of the sheep is 147 days (5

months less five days).

The birth weight should be 5 kg’s for single and

3.5 kg’s for twins.

As ewes approach lambing, they become

restless and often lie on the ground scratching

themselves.

They should not be interfered with if possible at

this stage but it is advisable to coax them into a


lambing pen. What are the advantages of a

pen?

In the pen the ewes can be watched at all

times and any lambing problems dealt with.

Before birth, the water bag should show

clearly. This means birth is about an hour away.

If birth does not happen an hour after the

water bag has shown, then the lamb probably

is in an abnormal position in the uterus (womb)

The normal order of birth is head first, with the

chin resting on the forelegs i.e. the forelegs first

The lamb may be pushed in if this position is not

seen at the initial stage.

14. After Birth

Immediately after birth, the nose and mouth of

the lamb is cleared from mucus. Why?

The naval is cut or carefully pulled to a length

of 7 – 10 cm and then dipped in iodine or

another disinfectant.


The ewe will usually lick the lamb clean and

dry. This actually stimulates blood circulation in

the lamb and warms it up.

If the ewe does not lick the lamb, then the

farmer or vet should rub the lamb with clean

straw.

A heater is often needed in a lambing pen.

It is very important that the lamb drinks as soon

as possible. The importance of colostrums must

be stressed. (Ewe or stomach tube)

If there is no milk, then colostrums from another

freshly lambed ewe can be used or cow’s

colostrums.

Cow’s colostrums can be frozen and stored for

emergencies.

After the birth of the lamb (about two hours)

the after birth should arrive.

This is the placenta, which provides the

connection between mother and off spring in

the womb.


Lambs should be left with their mothers in

individual lambing pens until properly

“mothered on”.

This usually takes about three days then they

can be put together with the other newly

lambed sheep.

15. The First few weeks after lambing.

Tail docking is carried out in the first week of

the lamb’s life.

This involves removing the lamb’s tail.

All lowland sheep have their tails docked /

removed but some farmers just remove the

ewe’s tails only.

In addition, all ram lambs not intended for

breeding are CASTRATED.

Castration and tail docking are performed with

the same tool – the “elastrator”.


This tool stretches a special strong rubber ring

so that it can be placed around the tail or the

scrotum!

This stops circulation in those areas and they

eventually just fall off!!!

In this time (after lambing) the ewe’s appetite

also increases dramatically and she drinks a lot

of water.

Concentrates should be used until good grass

is available for the lactating ewe. Then

precautions should be taken when on good

grass against grass tetany.

Grass tetany is caused by low Mg levels in the

grass.

16. Weaning

Lambs are weaned at 12 – 14 weeks old unless

already sold for slaughter!

They should be dosed before moving onto

fresh pasture, and then every three to six

weeks.


The lambs should be kept on clean / good

quality pasture all the time.

The ewe is placed on poor pasture. Why?

So that they are “dried up” and so that they

will not be too fat when flushed the following

year.

Vaccination of the lambs should take place

regularly against clostridial diseases. (Initially

after 6 weeks and then every six weeks)

17. Shearing and Summer Dip

Lowland sheep are shorn before the end of

May.

If wool production is important to the farmer,

then particular attention is given to the date of

shearing and the shearing is done when the

wool rises (weather dependant)

Sheep should not be sheared if their stomachs

are over full or when they are in heat.

Two weeks after shearing the sheep receive

their summer dip.


This is to prevent “fly strike”.

This refers to the blowfly or the green bottle fly,

which lays its eggs in the fleece and maggots

grow quickly.

Six months after lambing the booster injection

against clostridial diseases is administered.

18. Sheep Diseases

As species, sheep are much better adapted to

life on hills (their natural habitat).

Therefore, keeping them on lowland farms

causes health conditions that would not

otherwise arise.

Specifically, lowland sheep suffer more from

maggots, internal parasites and footrot.

The main reasons these conditions arise on

lowland flocks are climate and stocking rate.

Maggots are prevented on hills because the

harsh conditions simply do not allow them to

thrive.


Footrot is controlled on farms because sheep’s

hooves are naturally stronger due to more use

and wear.

A. Maggots / Fly Strike

Maggots are the larvae (young) of the blowfly

or the Green Bottle Fly.

The fly is attracted to odours in the fleece, and

they lay their eggs on dung–soiled wool.

Fly strike can be prevented by

1. Dipping in the Summer

2. Trimming excess wool around the tail

3. Tail docking

4. Grazing management (to prevent

scour)

An affected sheep is usually quite restless and

scratches the affected area frequently.

The area may appear green and wet.

Maggots should not be ignored and can often

be fatal!


B. Worms

Nearly all sheep carry intestinal parasites /

worms.

The older / more mature the animal the less

worms.

This is because older animals develop a certain

immunity to worms.

Why do ewes follow lambs, and not vice

versa?

Worms can only be controlled effectively with

both drugs and good pasture management.

All sheep should be dosed regularly and

pastures managed as top prevent the spread

of worms.

C. Liver Fluke

This is a “flat worm” which can cause death to

sheep or simply reduce thriftiness and lower the

quality of the carcase.


Both worms and liver fluke cannot reproduce

inside the sheep (host) so the number of larvae

eaten determine the extent of the disease.

D. Footrot

Footrot is a very serious problem on Irish Farms.

Footrot is caused by a bacteria, in fact many

different types of bacteria.

Footrot causes lameness, serious pain, reduced

food intake, in-activity and can lower fertility in

rams.

You can spot an affected sheep by seeing

them kneeling down while grazing.

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