Sheep Health and Management Flashcards
Stratified system
Unique to the UK
Perfectly designed to play on the strengths of different breeds, and the environments and habitats of the country.
Autumn in sheep managment
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
Sheep Abortions
<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
Enzootic Abortion of Ewes (EAE) -Chlamydophilia abortus.
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
Toxoplasmosis - Toxoplasma gondii
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
Post-tupping
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
External parasites
Lice - Bovicola ovis (Chewing/biting lice – feed on skin debris and hair)
Scab - Psoroptes ovis (sucking lice)
Pre-lambing
Ewes
Condition score and feeding considerations
Vaccination - pre lambing booster vaccinations
Clostridial Disease
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.
Pneumonia - Pasteurellosis
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
Orf - contagious pustular dermatitis
Parapoxvirus known as orf virus (ORFV) Differing strains Run its course 4-6weeks Poor growth rates Mastitis Secondary bacterial complications Zoonotic!
Lambing
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
Metabolic disease
Ovine pregnancy toxaemia/Twin lamb disease/Ketosis
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!
Metabolic disease
Milk Fever/hypocalcaemia
The body is unable to mobilise sufficient calcium from the bones to maintain the calcium level in the bloodstream
Nematodirus battus
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
Coccidiosis - Eimeria ovinoidalisandEimeria crandallis
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.
Post lambing
BCS recovery of ewes
Weaning policy – BCS and recovery of ewes
Sheering
Fly control
Lameness, worm control and parasite control need to be addressed
Internal Parasites
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.
Scald - interdigital dermatitis
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
Footrot
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.
