Lambing: Practical Rotation

Describe the 3 stages of labour in ewes

1. 2-6hrs: cervical dilation, behavioural changes, abdominal contractions, water bag appearance 

2. 1hr: passage of the lamb through the birth canal

3. Within 2-3hrs of stage 2: repulsion of the foetal membranes

When should you intervene to assist with lambing?

• Ewe trying to lamb for >1hr with no delivery

• No progress once lamb visible at vulva for 20 mins

• Frequent, powerful contractions but no delivery progress

• Ewe started to lamb and then stopped

• Lamb’s head visible but no forelimbs

• Foetal head and only one limb visible

• Only tail visible 

• Large and swollen lamb at vulva

• Parts of 2 limbs visible 

• Brown/smelly discharge

• Vaginal prolapse identified

What are the consequences of dystocia for lambs?

• Increased mortality rate 

• Higher incidence of neonatal infections

• Slower weight gain

• Increased costs of medication/care

What are the consequences of dystocia for ewes?

• Reduced colostrum/milk let down 

• Poor mothering behaviour 

• Higher costs of medication/care

• Potentially reduced future fertility

Draw out the 9 types of presentation in lambing ewes

What should you remember when assisting with lambing?

• Hygiene is very important: use arm length, disposable gloves and plenty of lubricant

• Gentle manipulation- uterus can be damaged if care is not taken, particular attention should be paid to protecting the uterine wall from hooves when re-positioning

• Do not use excessive traction

What are the colostrum requirements of lambs?

• 50ml/kg in the first 2hrs of life

• 250ml/kg during the first 24hrs of life

Describe the wet adoption fostering technique

• Rub fetal fluids from the ewe's own newborn lamb all over the foster lamb's head, back, and tail

• If the ewe has already licked her lamb dry, use a bucket to mix fluids with warm water to coat the foster lamb

• Introduce the foster lamb first, then her own, allowing her to lick both

Describe the skinning fostering technique

• Remove the skin from the dead lamb and create a "jacket" for the foster lamb

• Ensure the skin covers the lamb's body, leaving it on for a few days until the ewe accepts the scent

Describe the adopter crate fostering technique

• The ewe is secured in a head-lock crate, allowing her to stand but preventing her from turning away or attacking the new lamb, this allows the lamb to suckle safely

• Ewes are usually kept in these crates for 2–7 days

How can you identify the sex of a lamb?

Males: lift the tail, you will see 2 distinct testicles 

Females: no testicles are present

Why and when do we castrate lambs?

• Why: prevents inbreeding, allows effective breeding management, influences carcass composition and growth (higher amounts of fat)

• When: if lambs are intended for slaughter at a young age, there is probably no need to castrate 

Why and when do we tail dock lambs?

• Why: reduces amount of faecal contamination in the tail, reducing fly strike risk

• When: if fly strike is not a problem in the area, there is probably no need to tail dock 

How do we tail dock/castrate lambs?

• Apply a tight rubber band around the testicles/tail, fairly high up

What temperature should newborn lambs be, and how could you tell if they are hypothermic?

• Temperature should be 39-40℃

• 37-39℃= moderate hypothermia

• < 37℃= severe hypothermia

How can you treat ill lambs?

• Intraperitoneal glucose injection (20% glucose)

• Dry lamb and place in a warming box

• Stomach tubing: measure length of tube needed (mouth to shoulder), then place the tube in the side of the lamb’s mouth and insert it- lamb should not gasp

Describe ‘watery mouth’- including when lambs are affected, cause, treatment and prevention

• Typically affects lambs from 12-36hrs old

• Main cause is E.coli

• Treatment- antibiotics, antiinflammatory drugs 

• Prevention- ensuring good hygiene and adequate colostrum intake

Describe ‘joint ill’- including clinical signs, cause and transmission

• Hot, swollen and painful joints

• Caused by Streptococcus dysgalactiae

• May enter orally or via navel, docking, castrating or tagging wounds

Describe Entropian, including what it is, the effects and the treatment

• Lower eyelid rolls in and eyelids rub against surface of the eye 

• Makes lamb’s eyes runny, and the cornea cloudy

• Treatment- injections of penicillin parallel to the eyelid, or application of Michel clips to the eyelid to hold the eyelid out

Outline the effect and treatme/prevention of Coccidia

• Effect: scour (often bloody) and straining in lambs from 5 weeks-3 months, poor growth rates in lambs

• Treatment: anticoccidials, avoid mixing lambs of different ages

Outline the effect and treatment/prevention of nematodes

• Effect: diarrhoea and reduced growth rates 

• Treatment: grazing management, quarantine and anthelmintics 

Outline the effect and treatment/prevention of fluke

• Effect: reduced lambing percentages, reduced growth rates and sudden death

• Treatment: avoiding grazing areas where there might be mud snails, using flukicides when appropriate and quarantine 

Outline the effect and treatment/prevention of mites

• Effect: scratching, weight loss and fleece loss

• Treatment: endectocides such as sheep dip

Outline the effect and treatment/prevention of chewing lice

• Effect: scratching, weight loss and fleece loss

• Treatment: ectoparasiticides and shearing

Outline the cause and treatment/prevention of blow fly strike

• Cause: flies are attracted to soiled fleece, and lay eggs- larvae hatch, lacerate and liquefy the skin and attract more flies, resulting in severe wounds and maggot infestation

• Treatment: improving fly control and hygiene, removing fleece around back end (dagging) and protecting wounds with fly repellent

Outline the effect and treatment/prevention of ticks

• Effect: high numbers of ticks may cause anaemia, leading to weakness and may also transmit other diseases such as louping ill

• Treatment: ectoparasiticides

Draw out the life cycle of a typical sheep nematode

Describe the different classes of wormer

1. BZ (Benzimidazoles)- white drenches 

2. LV (Levamisoles)- yellow drenches 

3. ML (Macrocyclic-lactones)- clear drenches 

4. AD (Amino Acetonitrile Derivatives)- orange drenches

5. SI (Multi-actives)- purple drenches 

Describe the steps taken to prevent against lameness

1. Vaccinate: supports improving flock immunity against lameness-causing bacteria 

2. Cull: identify and remove sheep with severe/repeated bouts of lameness

3. Avoid: minimise infection spread during handling and on pasture, avoid high-risk environments, maintain dry tracks and prevent foot damage

4. Treat: treat all lame sheep promptly to reduce disease spread (antibiotics, foot sprays)

5. Quarantine: isolate lame/newly introduced sheep for at least 28 days 

Describe the transmission and prevention of abortion by Toxoplasma gondii (protozoan)

Transmission:

• Ingestion of oocysts shed in the faeces of infected cats

• Highly resistant in the environment, can survive for months/years on pasture/feed

Prevention:

• Isolate all ewes that have aborted, remove infectious materials, give vaccines

Describe the transmission and prevention of abortion by Chlamydia abortus (bacterial)

Transmission:

• Contact with infected placentas, aborted foetuses or vaginal discharges

Prevention:

• Isolate all ewes that have aborted, remove infectious materials, give vaccines, antibiotics are sometimes given

Describe the transmission and prevention of abortion by Campylobacter foetus/jejuni (bacterial)

Transmission:

• Usually enters through carrier animals, spreading through contaminated feed, water or direct contact

Prevention:

• Isolate all ewes that have aborted, remove infectious materials, no vaccines are available

Describe the infectious disease Caseous lymphadenitis (CLA), including the cause, transmission, clinical signs and control

• Cause: Corynebacterium pseudotuberculosis

• Transmission: contact with infective pus that drains from abscesses around lymph nodes

• Clinical signs: abscesses containing thick, green pus- which may rupture 

• Control: quarantine new stock, culling animals with abscesses, disinfecting shearing equipment, antibiotics are generally ineffective, vaccines are not widely available 

Describe the infectious disease Maedi visna (MV), including the cause, transmission, clinical signs and control

• Cause: a lentivirus

• Transmission: respiratory secretions, milk and colostrum

• Clinical signs: lungs and CNS, pneumonia, chronic mastitis and neurological signs may develop

• Control: testing flock, culling positive animals, using replacement stock from flocks certified free of MV

Describe the infectious disease Ovine pulmonary adenocarcinoma (OPA), including the cause, transmission, clinical signs and control

• Cause: a retrovirus 

• Transmission: respiratory secretions, possibly milk and colostrum

• Clinical signs: chronic pneumonia- coughing, weight loss, etc

• Control: there is no treatment, but affected sheep should be isolated and culled promptly

Describe the infectious disease Johne’s disease, including the cause, transmission, clinical signs and control

• Cause: Mycobacterium avium subspecies paratuberculosis (MAP)

• Transmission: contaminated faeces 

• Clinical signs: weight loss, diarrhoea, decreased milk production 

• Control: testing and culling infected animals and offspring, vaccine available in some regions

Describe the infectious disease Border disease, including the cause, transmission, clinical signs and control

• Cause: pestivirus (BVD)

• Transmission: contact with infected secretions

• Clinical signs: stillbirths, birth of weak lambs with neurological/developmental issues, high rates of ewe infertility

• Control: quarantine and testing new stock, identification of affected animals, good biosecurity

Describe the clostridial condition ‘pulpy kidney‘, including the clostridial cause and clinical signs

Cause: C perfringens (D)

Clinical signs: sudden death in weaned lambs (younger if ewes not vaccinated)

Describe the clostridial condition ‘struck‘, including the clostridial cause and clinical signs

Cause: C perfringens (C)

Clinical signs: sudden death in adult sheep

Describe the clostridial condition ‘lamb dysentery‘, including the clostridial cause and clinical signs

Cause: C perfringens (B)

Clinical signs: sudden death in lambs, blood tinged diarrhoea

Describe the clostridial condition ‘tetanus‘, including the clostridial cause and clinical signs

Cause: C tetani

Clinical signs: ascending spastic paralysis, lateral recumbancy, seizures, death

Describe the clostridial condition ‘botulism‘, including the clostridial cause and clinical signs

Cause: C botulinum

Clinical signs: flaccid paralysis followed by death

Describe the clostridial condition ‘black disease‘, including the clostridial cause and clinical signs

Cause: C novyi

Clinical signs: sudden death in late summer/early autumn

Describe the clostridial condition ‘braxy‘, including the clostridial cause and clinical signs

Cause: C septicum

Clinical signs: sudden death in weaned lambs in winter 

Describe the clostridial condition ‘blackleg‘, including the clostridial cause and clinical signs

Cause: C chauvoei

Clinical signs: lameness, pyrexia, dullness, anorexia, sudden death

Describe the clostridial condition ‘malignant oedema‘, including the clostridial cause and clinical signs

Cause: C septicum

Clinical signs: swelling of the head

Describe Schallenberg virus, including transmission, clinical signs and control

Transmission: midge vector

Clinical signs: abortions, malformed lambs

Control: vaccination

Describe Bluetongue virus, including transmission, clinical signs and control

Transmission: midge vector

Clinical signs: depression, fever, mouth ulcers, coronary band inflammation

Control: vaccination

Describe foot and mouth disease, including transmission, clinical signs and control

Transmission: aerosol, people, fomites

Clinical signs: fever, mouth and hoof vesicles

Control: culling

Describe scrapie, including transmission, clinical signs and control

Transmission: milk, colostrum, secretions

Clinical signs: incoordination, odd behaviour, weight loss

Control: culling and resistant breeding

When should you start health planning?

• Ideally 8 weeks before tupping at the start of the sheep year

• Can also be 6 weeks after the end of lambing

What are some common diseases in new stock?

• Ezoonotic abortion

• Maedi visna

• Caseous lymphadenitis 

• OPA

• CODD
  Orf

• Sheeb scab

• Roundworms and liver fluke

Describe the key points of health planning

• Biosecurity section is essential 

• Health planning helps to monitor disease outbreaks and give advance warnings 

• Can be recorded by paper, wall planner, computerised or web-based 

• Record: production figures, treatments, disease, blood sampling results 

• Health planning is a requirement for the Sheep Welfare Code and certain farm assurances