Disease control and epidemiology Flashcards
Veterinary involvement in the control of poultry disease
Health
- vaccination
- monitoring of bird health, cleaning, and vaccine administration
Performance
- noticing variations from the norm
- problems relating to housing and day old quality
Welfare
Biosecurity
Food hygiene
Routine serology of poultry
Measuring humoral antibody response in the bird in response to
□ Disease challenge
□ Vaccine administration
□ Measure maternal antibody passed from Hen to chick
Dependant
□ Humoral antibody production
□ Reliable and repeatable measuring
Sample size for routine testing of poultry
For official testing the sample size needs to be statistically significant, recommendation is 60 samples per airspace
In practice 20 samples recommended per shed for routine monitoring
Sample collection of routine poultry testing
Adequate sample volume
Treated tubes
Transport quickly to the laboratory to avoid haemolysis
Sample preparation and storage for poultry serology
Serum taken off
Serum centrifuged at 3000rev/min for 3 minutes
Heat treat sera (not required for ELISA but if RPA or HI it is)
Store aliquots at 20 degrees
Serology tests available for poultry
Rapid plate agglutination
○ Stained antigen
○ Mycoplasma and salmonella pullorum
○ Rapid
○ Cheap
○ Useful screening
○ Non-specific agglutination quite common
Latex agglutination
ELISA
○ Relatively cheap
○ Automated
○ Repeatable and comparable
○ Range of tests available
Haemagglutination inhibition
○ Useful for IBV can differentiate the various serotypes
○ Subjective and requires skilled labour
Virus neutralisation
Health reviews for poultry
Paired serum sampling to assess health issues
Routine storage of sera during flock life e.g. Every 6 weeks
Bleed 2 weeks after challenge to allow antibody response to develop
Clubbed down issues in progeny
- Clubbed down chicks
- Poor hatchability and chick viability
- Usually associated with vit B2, zinc def
- Has been associated with FAV-1
- No increase in FAV 1 antibodies over time of clubbed down chicks
- Good seroconversion at onset of lay
Virology in poultry
Don’t usually undertake this in house
Send to government lab
PCR techniques much more readily available for a range of pathogens with WGS to enable more precise epidemiology
Therapeutics in poultry
Limited number of antimicrobials licensed for use in food producing animals
Less so in poultry
○ Costs of relicensing
○ Return on investment
In feed coccidiostats in broiler feed
○ In Europe standard inclusion
○ Manage the infestation
