Poultry health and Diseases Flashcards
Sick hen symptoms
- Ruffled feathers
- Inactive
- Drooping wings
- Eyes closed
- Sitting in haunches, lying on side
- Dull eyes, lifelessness (as opposed to alertness)
- Discoloured and shrunken combs
- Reduced colour & moisture of linings of vent, mouth, eyes.
Distinguishing features of poultry production & influence disease risks
- Very Large flock size and stocking density requiring
- Low unit value of birds requiring
- Pattern of ownership and vertical integration as opportunity for
- Changed production systems alters
How poultry disease spreads
people (boots, clothes etc)
Vechiles (manure spreading, trucks, front end loader)
Bird to bird (carcasses, manure, litter/debris, feathers)
poultry equipment (filler flats, hauling crates/coops, feeder, waterers
Basics of disease control
- Biosecurity
- Vaccination
- Health Monitoring
- Medication
Features of biosecurity in
commercial poultry
foot baths
PPE
shower in
on facility clothes (overalls, boots, gloves)
Visit younger birds first as more suseptible then move to older
Regular monitioring
No animals around sheds
Vaccination’s for broliers
Marek’s Disease MDV(in ovo)
* Infectious Bronchitis IB (spray)
* Newcastle Disease NDV(spray or drinking water)
What diseases are egg transmissible
Mycoplasma, IBD, FAV, CAV, Salmonella
health monitoring
Sounds –> if quiet its “deadly quiet”
Feed stuck to beaks (mucus)
Stick heads out to look at you
Disease in chickens
Newcastle Disease Virus (highly contagious and lethal)
Mareks disease virus
Salmonella
Avian Influenza
Bronchitis virus
Responses to AIV and NDV outbreaks
slaughter infected and in contact poultry
decontamiate
strict quarantine
movement controls
tracing and surveillance
Pathogens for public health
Salmonella
Immunosuppresive diseases
mareks disease virus
Reducing productivity diseases
Infectious bronchitis
Coccidiosis
Contemporay problems in broilers and layers
Free range issues with health
Spotty Liver Disease in free range layers
Salmonella Enteritidis in Australian layers
Immunosuppression issues in broilers – Infectious
Bursal Disease and Inclusion Body Hepatitis
Free range layer issues
prefer shade
Interact with other animals/ birds
Range densisties regulations differ between each organisation
› Outside – uncontrolled vegetation access/ no feed or water
› If feed intake inadequate:
- Peaking body weight is too light
- Post production dips
- Mortality from cannibalism (called “Egg peritonitis”) – a real problem with large
flocks
- Inadequate feed or nest space may predispose to disease (e.g. Spotty Liver
Syndrome)
Probs in alternative systems
› Problems in Alternative Production Systems
- Free Range Broilers
- Necrotic Enteritis
- Dysbacteriosis
- Free Range and Barn Layers
- Spotty Liver Disease
- Fowl Cholera
- Internal Parasites
- Cannibalism
Problems with cannibalism
› Social structure of flock
- Pecking order – natural bird behaviour
› Dominance hierarchy behaviour of chickens
- Difficult to stop this in commercial conditions
- Group size
› Problem tends to occur around point of lay and 60
weeks of age
› Can be difficult to control, unless triggers identified,
multifactor
› Can leading to septicaemia or death from cannibalism
› Beak trimming/treatment; light intensity, difficult in
free-range
Stressors leading to targeted feather pecking
Temperatures
Humidity
light intensity or uneven spread
Inadequate nutrients
low fibre
unbalanced diet
noise
staff changes
visitors
poor brooding
poor faciliies
poor health
inadequate stockmanship
not mooving calmly and quietly
Spotty liver syndrome
jaundice
high mortality and morbididty
effects egg production
rapid response to antibiotics
Koch’s postulates of Spotty liver
- the microorganism or other pathogen must be present in all cases of the disease
This was demonstrated by PCR on livers - the pathogen can be isolated from the diseased host and grown in pure culture
Once the slow growing organism could be
cultured it was readily found on culture - the pathogen from the pure culture must cause the disease when inoculated into a healthy, susceptible laboratory animal
“Susceptible” required birds to be at sexual
maturity - the pathogen must be reisolated from the new host and shown to be the same as the originally inoculated pathogen
Successful
Immune suppression ay sexual maturity
Only in hens
cell mediated but not humeral suppressed
allows organisms in gut to activate and multiply
Antibody deposited in egg yolk = maternal immunity
Spotty Liver Disease (SLD) found:
in every shed with scratch area
Survey suggests no more than
112 b/m2 to reduce risk of SLD
- Brown egg layers need more nest
space than white egg layers
Sources of salmonella infection
› From primary breeders
› Rodents, wild birds, insects
› Pets, other livestock
› Fomites
› Feed
› Water
› Litter
› Humans
Salmonella in eggs
found in caeca
infect ovum (yolk) and albumen (white) before egg layed
