Under-performance in poultry Flashcards
Describe a poultry pyramid
TOP:
Pure line genetic flock - genetic companies
Great grandparents - genetic companies
Grandparents - Integrator/genetic companies
Parent flocks - Integrator companies
Broilers or layers - Integrators/ farmers
BOTTOM OF PYRAMID
Where does crop sit (crop, proventriculus or gizzard)?
Gizzard
How much of the market do free range eggs make up?
43%
Describe enriched cages
potential to nest potential to roost potential to scratch potential to stretch 15 birds/pen produces cleaner eggs
Name 3 laying systems
free range: access to fields and barn
enriched colony cage - 750cm2/bird
barns - 11 hens per m2
Describe hen lifecycle
- 0-16 w birds are reared in bars on pullet rearing farm (20 vaccines in this time, most in water)
- pullet moved to laying farm
- 18-20 w pullet starts to lay (very small eggs to start)
- pullet becomes a ‘layer’ and lives until 72 w (aim to increase to 100d)
Outline diagnostics in poultry
FLOCK LEVEL!
- serology (Ab titres, 10% flock)
- swabs (PCR/bacteriology culture and sensitivity)
- virus isolation
- FEC, cocci oocyst counts
- PME
How is mycoplasma tested for?
PCR
Main cause - under-performance in layers
Poor management
CS - poor management in layers
- egg production drop
- change in egg shell quality
- change in egg size
- mortality
- water/feed intake reduction
List some dz affecting layers
- infectious bronchitis (IB)
- mycoplasma
- peritonitis
- endoparasites and ectoparasites
- POOR MANAGEMENT
What is IB?
- common virus
- coronavirus
- virus mutates readily –> many shells (>100 strains)
CS - IB
- snicking
- watery eyes/nose
- head shaking
- ‘wrinkly egg’s
Pathogenesis - IB
- IB damages cilia in respiratory tract –> infected birds cannot remove mucus containing these bugs out of lower respiratory system –> allows bacteria and viruses better access to the air sacs than in healthy birds
- once in the air sacs bacteria (e.g. Pasteurella, E.coli) can cause air sacculitis and even cross the thin air sac wall into abdomen to cause peritonitis and death
Dx and prevention of IB
- PCR swabs (cloacal, 10 samples), 1st point of call
- paired serology (£600 so commercial flocks only)
- ensure good vaccination technique (rear)
- ensure correct vaccines are used at correct time (q6-8 weeks during lay)
Describe mycoplasma infection
- bigger than a virus, smaller than a bacteria
- 23 different types with M.gallisepticum most prevalent
- once infected birds remain infected for life
CS - mycoplasma
- swollen head
- swollen tissue around eye
- bubbles in corner of eye
- wrinkly white eggs
- affects flying ability?
Transmission - mycoplasma
- adult to chick through egg/semen
- bird to bird: sneezing, coughing, directly or through water system
- incubation period is 6-10d
- infected birds on farm boundary to neighbouring farms
- from wild bird population
Describe peritonitis
- most common dx in adults, secondary to almost all dz
- stress and coming into lay
- oviduct and tracheal similarities
- primary/secondary
- many types of E.coli involed
- tx included AB based on C+S (4 types with 0d egg withdrawal, 2 work = Denigrad and tylan. You can’t use baytril in layers as specifically contraindicated on the datasheet)
- Vaccines - 2 types - 1 commerical, covers many E.coli strains, other is specific autogenous vaccine to farm based on farm E.coli type
Outline worm tx
- Fubenvet in feed licensed fro 7d
- Solubenol in water licensed for 7d
- Fimabo in water licensed for 7 days
- Panacure Aquasol licensed for 5 days (expensive, commercial only)
What are the different worm types?
- Ascaridia galli (round worm, intestinal)
- Capillaria (hair worm, crop)
- Heterakis gallinarum (caecum, carries Blackhead - not good, causes sudden death, hobnail liver lesions, caecal ulcers)
- Syngamus trachea = gape worm
- PPP vary 14-21 days
Describe red mite
- v common
- nocturnal
- vampires of poultry world
- think fleas!
- you may not know the birds have an infestation
- visible to naked eye
- life cycle can be as short as 10d in warm weather
- can liver 2 y w/o eating
- tx is a powder, organic, causes outer skin of mite to be scratched out –> dehydration
CS - underperformance in broilers
- underweight
- reduced water consumption
- reduced feed intake
- CS - enteritis, diarrhoea
Describe broiler life cycle
- chick placed weigh 40-50g
- kept until 30-65d then slaughtered
- birds remain on same farm until cleared
- standards kept in barns whole life, max crop 100,000
- free range kept in barns until 21d of age then allowed out until clearing, 10,000 birds maximum
- organic kept in small sheds allowed out from 21 days, max crop size 5000
How can prevalence of pododermatitis be reduced?
lifting nipple feeders higher as birds grow/ get older
Name diseases in BROILERS
- IB
- Infectious Bursal Disease = IBD (Gumboro)
- coccidiosis
- enteritis/ dysbacteriosis
Outline IBD
= Infectious bursal disease
- bursa is the bird immune system HQ
- aka Gumboro dz
- affects B cells in bursa of fabricius
- birnavirus
- NOT zoonotic
- damages immune system –> other conditions
- vaccinated at 18, 24 and 28 d in some cases
Outline coccidioss in BROILERS
- Eimeria acervulina at 14d : won’t kill birds but they slow in growth and become uneven
- E. tenella (blood) at 25d : kills birds
- sometimes secondary necrotic enteritis
- 8 spp of cocci affect layers and 5 spp of cocci affect broilers (d/t lifespan)
Outline cocci control
- coccidiostats ionophores
- chemical cocci tx (Baycox/Ampolium, virkon useless)
- cleaning of houses with chemicals that kill oocysts
- burning of barn floors (most effective)
Outline enteritis/ dysbacteritis
- bacterial scour (usually clostridia)
- variable causes (secondary to lots of things)
- difficult to tx (Amoxicillin)
- next stage is necrotic enteritis
- cholangiohepatitis
Outline neteritis
- Clostridia perfingens type C
- spike in mortality
- penicillin sensitive
- associated with coccidia
- possibly low mortality followed by secondary cholangiohepatitis
