Lambing

What is the average lamb mortality rate by day 3 post lambing?

10-25% mainly due to:
- Dystocia
- Stillbirth
- Hypothermia or starvation
- Infection
- Non-infectious diseases

How long is a ewe's oestrus cycle?

Approximately 17 days

How many cycles is the ram left with the ewes for?

2 cycles, or 34 days.

How many ewes per ram during tupping?

1 ram per 40 ewes.

When are ewes scanned?

45 - 90 days post tupping.

What is the gestation length of a ewe?

143 to 147 days.

How many stages are there in a ewe's labour?

3

What happens during 1st stage labour?

3-6 hours duration, towards the longer end for gimmers. Ewes show increased activity (nest-building) and seperate from the flock. Subtle abdominal contractions may be evident, and the cervical mucus plug will be seen hanging from the vulva.

What happens during the 2nd stage of labour?

10-60 mins duration. Active and powerful straining is obvious, and sheep are most often in lateral recumbency. Once a normal presentation is obvious, the lamb should be born within 15 minutes.

What happens during 3rd stage labour?

2-3 hours after the lamb is born. The foetal membranes are expelled.

When should you intervene?

- 1st stage continues for more than 4 hours
- 2nd stage continues for more than 2 hours
- Obvious malpresentation
- No second lamb after 30 minutes
- Prolonged unproductive straining for over 30 mins

Abnormal presentation - both legs first. What do you do?

Pull the lamb out in a straight line, parallel to the ewe's spine, rather than 'diving'.

Abnormal presentation - one front leg back. What do you do?

Repulse the lamb, then pull the front legs forward and lamb as usual. This must be done before the head is hanging out of the vulva.

Abnormal presentation - head out only (bilateral shoulder flexion). What do you do?

Repulse the lamb, then pull the front legs forward and lamb as usual.

Abnormal presentation - breech. What do you do?

Repulse the lamb, then bring the hind limbs to vulva, and lamb hind legs first.

Twin presentation - what do you do?

Push one lamb backwards and pull the first lamb out. Then pull out the second lamb.

Abnormal presentation - head to the side. What do you do?

Repulse the lamb and pull the head to the fore. Use a snare to keep the head up. Lamb is often dead in this situation.

What is metritis?

Infection of the uterus. A squelae of poor lambing practice. Ewe will be dull, have a poor milk yield and a smelly swollen vulva with red brown discharge. Treated with antibiotics.

What is ringwomb?

Failure of the cervix to dilate. The cervix can be manually dilated or a C-section is needed.

What is vaginal prolapse?

When the vagina and cervix are pushed out. This generally occurs in over-fat animals but other risk factors include lack of movement, high fibre diet, triplets, lameness. Treatment includes lambing, retain with a harness, Buhner suture.

What is a uterine prolapse?

When the uterus is expelled along with the lamb. This requires an epidural, antibiotics and NSAIDs. Sugar could be used to shrink it, but this encourages bacterial growth.

What is evisceration through a vaginal tear?

In late gestation, the intestines are pushed out of the body through a tear in the dorsal vaginal wall. Euthanasia is the only treatment.

What is pregnancy toxaemia/ twin lamb disease?

Occurs when energy demands exceed supply. Clinical signs include isolation, depression, lethargy, weakness. Treatment includes palatable feeds to promote appetite, IV glucose

What is hypocalcaemia?

When calcium levels drop too low. Sheep are depressed and weak, with ruminal stasis and bloat, and refluxed ruminal contents around the nostrils and lower jaw. Treatment is IV calcium.

What is acute mastitis?

A bacterial infection that causes heat, pain, swelling of the teats. Ewe will not feed their lambs and may have clots in their milk.

What is chronic mastitis?

A squelae of acute mastitis that is ongoing. Palpable masses may be felt in the teats. May be caused by the virus Maedi visna.

What are the risk factors and prevention for mastitis?

Poor udder conformation, poor hygiene, teat lesions. Prevention includes maintaining ewes at BCS 3, and putting them on a low plane of nutrition post-weaning to allow them to dry off.

What are the target birthweights of lambs?

- Single lambs should be 5.5 to 7.0kg
- Twins should be 5.0 to 6.0kg
- Triplets should be greater than 4.0kg
- Hill breeds may be about 1kg less than targets.

How to get a lamb to breathe

- Break the amniotic sac
- Rub the chest
- Swing the lamb by its back legs
- Stimulate the nostrils
- Use a respiratory stimulant

How much colostrum do lambs need?

- 50ml/kg in the first 2 hours ideally, or the first 6.
- 200ml/kg in the first 24 hours.

Why do lambs need colostrum?

- High fat content provides energy
- Source of antibodies

How can a lamb receive colostrum aside from naturally?

- Hand milk the ewe
- Give colostrum from another ewe
- Buy in colostrum from another farm
- Cow colostrum

How is the navel dressed?

- 10% iodine in an alcohol base (strong iodine)
- The navel should be dressed in the first 15 minutes of life, and then 2-4 hours later

How to prevent hypothermia in lambs?

- Ensure ewes have sufficient condition.
- Ensure ewe-lamb bond is established
- Ensure lambs are well-fed.
- Ensure lambs are dry.

What do you do when a lamb has secondary hypothermia?

Give colostrum or an abdominal injection of water-glucose before warming the lamb.

What is watery mouth?

E.coli colonisation of the gut. This is due to intensive husbandry, poor hygiene, contaminated fleece, insufficient colostrum intake. Lambs appear lethargic and depressed, and salivate profusely.
Treatment includes soapy water enemas, laxatives, oral antibiotics, oral electrolyte therapy.

What is navel ill?

Swelling around the navel, indicating that bacteria has entered. Prevention includes navel dressing, hygiene and colostrum intake. Antibiotics are used to treat.

How may tails be docked?

Constriction device can be used in the first 7 days.
Hot iron tail docking can be carried out up to 2 months using anaesthetic.
Clamping and surgical removal must be carried out by a vet.

How may lambs be castrated?

Constriction device can be used in the first 7 dats.
Bloodless castration can be used until the lamb is 3 months old.

What tags do lambs require?

All sheep must have an EID. For indoor lambs, this must be fitted by 6 months, or. 9 months for outdoor lambs. Another ear tag is also required.