Poultry Underperformance Flashcards
GIT
- crop
- proventriculus
- gizzard (grit needed here)
Outline how air sacs work
- air goes straight to back air sacs (resp disease occours here)
- then exhale back through the parabronchi)
Different laying systems
> free range- access to fields and barn
enriched colony cage - min space per bird, 15 birds per cage
barn - 11hens/m2
* free range or enriched colony may be better welfare depending on level of each*
Outline hen life cycle
> 0-16 weeks birds reared on pullet rearing farm (20vax in this time)
16w pullet moved to laying farm (sensitive time, lighting etc)
18-20w start in lay
pullet becomes a layer and lives until 72w old (if rescued and lives to 2-3y old this is very good! Don’t expect too much laying wise)
Diagnostics in poultry
@16w take bloods for serology (cross over point moving to new farm)
- serology ab titre
- swabs (PCR/bacteriology culture and Sensitivity esp For mycoplasma)
- virus isolation (good chicks, mush up and test)
- worm egg counts, cocci oocyst counts
- POST MORTEM
Most common causes of underperformance in layers
Poor management
Symptoms of underperformance in layers
- egg production drop
- change in egg shell quality (chronic dz, calcium deposits/crinkly/white)
- change in egg size (feed ^\v and management)
- mortality (mostly 2* infections, 0.5%-30% organic)
- water/feed intake reduction (only if farmers very vigilant recording)
Diseases affecting layers
> infectious bronchitis (IB) > mycoplasma > peritonitis - often 2* to a lot of other things > endo and ectoparasites > poor management
What is IB? Clinical signs
- common virus
- coronavirus, very high mutation rate
- several strains
- snicking, watery eyes and nose, head shaking
- wrinkly eggs
Pathophysiology of IB
- damages cilia
- 2* infection
- air sacs become infected
> AT PM ANYTHING ON AIR SACS IS ABNORMAL, SHOULD BE TOTALLY CLEAR LIKE CLINGFILM
Diagnosing and preventing IB
- PCR swabs and paired serology
- ensure good vax tachnique (at night)
- ensure correct vaccines are used at correct time
What is mycoplasma? Clinical signs?
- persistent infection (only way to eradicate is CULL)
- bigger than a virus, smaller than a bacteria
- m. Gallisepticum most prevalent, 20 types
- swollen head, swollen tissue around eyes, bubbles in corner of the eye, wrinkly WHITE eggs
How is mycoplasma transmitted
- adult to chick through egg or semen
- bird to bird (sneezing, coughing, fomites, through water system)
- incubation 6-10d
- advise not to sell on birds from mycoplasma + flocks
- neighbouring farms
- wild bird populations
What causes peritonitis
> E. coli (different types involved)
most common dx adult bird
- stress and coming into lay
- oviduct and tracheal similarities
1* or 2*
Tx Abx
- Deniguard and Tylan only 2 Abx lic and effective
NOT baytril (contraindicated in laying birds so can never eat their eggs)
vax options
- autologous vax from samples on the farm to make it specific to E. coli subtypes on farm
Worm Tx
- Flubenvet in feed LIC 7d
- Solubenol in water LIC 7d
- Flimabo in water LIC 7d
- Panache Aquasol LIC 5d
Worms
> ascaridia galli - intestinal roundworm > capillaria - hair worm, crop > heterakis gallinarium - caecum - carries blackhead (-> sudden death, hobnail liver lesions, ceacal ulcers, UNTREATABLE) > synagmus trachea - gape worm * ppp vary 14-21d
What is the most common ectoparasites affecting chickens?
> red mites
- v common
- nocturnal
- think fleas!!!
- visable to naked eye
- life cycle can be 10d in warm weather
- can live 2y without feeding
Tx red mite
- dichromatious earth
- introduce other bigger mites ? Echo
Signs of underperformance in broilers
- underweight (usually measured weekly or daily!)
- reduced feed and water intake
- clinical symptoms
Broiler life cycle
- chicks placed 40-50g
- kept until 30-65d (‘thinned’ at 30d taking out a 1/4 of the flock to keep under the weight limit per m2)
- remain on same farm until cleared
Outline broiler systems
- standards kept in barns all their life (access to perches, bails etc but these aren’t used as broilers so fat and lazy) 100,000/shed
- free range 11,000/shed
- organics small shed (5,000?) small sheds allowed outside from 21d old
Issues with drinkers
- raise up nipples as birds grow
- should drink at 45* angle
- otherwise litter will get wet and pododermatitis ensues
Diseases in broilers
- IB
- IBD (gumboro)
- COCCIDIOSIS main dz
- enteritis/dysbacteriosis
What is IBD
> infectious bursa disease = gumboro dz
- bursa=immune system HQ
- affects B cells in bursa of fabricius
- birnavirus
- non-zoonotic
- immune system damage PDF other dz
Prevention IBD
Vax @ 18, 24, 28 d
- broilers only, doesn’t affect layers
Coccidiosis
- acervulina @ 14d won’t kill but v growth
- tenella (blood)@ 25d - kills birds
- 2* necrotic enteritis common
- 8 species of cocci affect layers and 5 affect broilers (life span)
Cocci control
- coccidiostats ionophores
- chemical coccidiostats (baycox, ampolium, NOT VIRKON)
- cleaning houses to kill oocysts
- burn barn floors (can be more effective than chemicals)
Enteritis 2 stages
> dysbacteriosis - bacterial scour (Clostridia mainly) - variable causes - difficult to tx (amoxicillin) - next stage is necrotic enteritis - cholangiohelatitis > necrotic enteritis - Clostridia perfringens type c - spike in mortality - penicillin sensitive - associated with cocci - poss low mortality followed by 2* cholangiohepatitis
How does the pyramid of poultry production work?
- pure line genetic flock (genetic companies)
- great grandparents (genetic companies)
- grandparents (integrators: all levels of production/genetic companies) here up very high biosecurity
- parent flock (integrator companies)
- broilers layer s (integrator farmers)
