Sheep Health and Management

Question 1

Stratified system

Answer 1

Unique to the UK

Perfectly designed to play on the strengths of different breeds, and the environments and habitats of the country.

Question 2

Autumn in sheep managment

Answer 2

Getting ready for breeding: 
Rams
Fertility and condition score
Ewes: 
Cull ewes based on udder, feet, mouth
Condition score 
Trace element status – Selenium, Copper, Cobalt, Iodine
Vaccination against abortion
Liver fluke 
Breeding considerations
Teasers
Ram to Ewe ratio (lower ratios for ram lambs)
Mating length (2-3 cycles x 17days)
Mating ewe lambs – 60% of mature weight
”Flushing

Question 3

Sheep Abortions

Answer 3

<2% abortions each year otherwise it is likely to mean there is an infectious cause of abortion in the flock.

The most common causes of abortion in the UK are Enzootic abortion (EAE) and Toxoplasmosis

Question 4

Enzootic Abortion of Ewes (EAE) -Chlamydophilia abortus.

Answer 4

Abortions usually happen in the last 2-3 weeks of pregnancy.
Aborting ewes shed vast amounts of the organism
Causes a thickened placenta = abortion.
Weak live lambs may also be born.
Long incubation period

Question 5

Toxoplasmosis - Toxoplasma gondii

Answer 5

Problems depend on the stage of pregnancy
Early in pregnancy the ewes may be scanned barren,
Later infection can cause re-absorptions, mummified lambs, abortions, still births and weak lambs.
Twin lambs – one fine the other mumified
Strawberry Cotyledons

Question 6

Post-tupping

Answer 6

Rams
BCS Score loss – TLC
Ram @ £550
1 yr – 40 ewes – 150% = £9/lamb sired
4 yrs – 60ewes/year – 150% = £1.50/lamb sired
Ewes
Pregnancy scan (40-90days)
Trace elements 
Liver fluke 
External parasites
Housing

Question 7

External parasites

Answer 7

Lice - Bovicola ovis (Chewing/biting lice – feed on skin debris and hair)

Scab - Psoroptes ovis (sucking lice)

Question 8

Pre-lambing

Answer 8

Ewes
Condition score and feeding considerations
Vaccination - pre lambing booster vaccinations

Question 9

Clostridial Disease

Answer 9

Sudden death
Ubiquitous in the environment and healthy animals
Infections progress rapidly = treatment is rarely effective.
Effort must be focussed on ensuring good immunity against disease through effective vaccination strategies.

Question 10

Pneumonia - Pasteurellosis

Answer 10

Stress i.e. Marts, weaning, transport
Infectious agents - Mannheimia haemolytica,Bibersteinia trehalosiandPasteurella multocida
There are two distinct syndromes of pasteurellosis:
a) Septicaemia = Sudden death
b) Respiratory disease = Fever,Depression, laboured breathing, cough, nasal discharge, conjunctivitis

Question 11

Orf - contagious pustular dermatitis

Answer 11

Parapoxvirus known as orf virus (ORFV)
Differing strains
Run its course 4-6weeks
Poor growth rates 
Mastitis
Secondary bacterial complications
Zoonotic!

Question 12

Lambing

Answer 12

Lambing management - Look out for problems; prolapse, twin lamb disease, hypocalcaemia and ewes struggling to give birth.

Castration and tailing policy 
(Flystrike and unwanted pregnancies)
Nematodirus battus
Coccidiosis 
First dose of clostridial/pasteurella vaccine +/- Orf

Question 13

Metabolic disease

Ovine pregnancy toxaemia/Twin lamb disease/Ketosis

Answer 13

Negative energy balance, as the ewe is unable to supply enough energy to meet her own demands as well as those of the fast-growing foetuses.
Stress!

Question 14

Metabolic disease

Milk Fever/hypocalcaemia

Answer 14

The body is unable to mobilise sufficient calcium from the bones to maintain the calcium level in the bloodstream

Question 15

Nematodirus battus

Answer 15

Disrupt the mucosa in the small intestine -> Profuse watery scour -> poor growth -> death
Development of the larvae takes place within the egg (can survive for 2 years).
Requires a period of cold weather followed by warmer temperatures of 10°C+
A mass hatch + lambs starting to eat grass (6-12weeks)
FEC are ineffective because the disease is caused by the larvae and adults before they start laying eggs
Infection one year to the next

Question 16

Coccidiosis - Eimeria ovinoidalisandEimeria crandallis

Answer 16

Ingestion oocysts by lambs -> hatch -> invade the gut cells -> burst cells open -> damage -> scour + mucus and blood.
Often ewes are the original source of infection
It takes two to three weeks from infection to passing oocysts.
Affects later born lambs as environmental contamination builds up
Pathogenic coccidia oocysts can survive overwinter and add to environmental loads.

Question 17

Post lambing

Answer 17

BCS recovery of ewes
Weaning policy – BCS and recovery of ewes
Sheering
Fly control
Lameness, worm control and parasite control need to be addressed

Question 18

Internal Parasites

Answer 18

Step 1
All roundworms begin as eggs. These eggs are produced by female adult roundworms living in the gut of the animal.
Step 2
These eggs are passed out in the animal’s dung onto the ground.
Step 3
The eggs hatch into larvae, given the right environmental conditions (sufficient moisture levels and temperature).
Step 4
The larvae develop and become infective. They move up blades of grass in water droplets, where they can be eaten by grazing sheep.
Step 5
Once ingested, the larvae enter the gut of the animal and develop into adults whilst causing significant damage and production effectives if the animal is not immune.

Question 19

Scald - interdigital dermatitis

Answer 19

Footrot and scald = both caused by Dichelobacter nodosus
Scaldis the milder
Affects the skin in the interdigital space
Wet weather, damp pastures, and mud are predisposing factors.
Redness, swelling and some white exudate

Question 20

Footrot

Answer 20

Scald can progress tofootrot
The infection spreads separating the horn tissue from the sole and can extend up the wall
Characteristic foul-smelling discharge.
Chronic infection leads to grossly mis-shapen and overgrown hooves.