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
