Poultry Underperformance

Question 1

GIT

Answer 1

• crop
• proventriculus
• gizzard (grit needed here)

Question 2

Outline how air sacs work

Answer 2

• air goes straight to back air sacs (resp disease occours here)
• then exhale back through the parabronchi)

Question 3

Different laying systems

Answer 3

> 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*

Question 4

Outline hen life cycle

Answer 4

> 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)

Question 5

Diagnostics in poultry

Answer 5

@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

Question 6

Most common causes of underperformance in layers

Answer 6

Poor management

Question 7

Symptoms of underperformance in layers

Answer 7

• 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)

Question 8

Diseases affecting layers

Answer 8

> infectious bronchitis (IB)
> mycoplasma 
> peritonitis 
- often 2* to a lot of other things
> endo and ectoparasites
> poor management

Question 9

What is IB? Clinical signs

Answer 9

• common virus
• coronavirus, very high mutation rate
• several strains
• snicking, watery eyes and nose, head shaking
• wrinkly eggs

Question 10

Pathophysiology of IB

Answer 10

• damages cilia
• 2* infection
• air sacs become infected
  > AT PM ANYTHING ON AIR SACS IS ABNORMAL, SHOULD BE TOTALLY CLEAR LIKE CLINGFILM

Question 11

Diagnosing and preventing IB

Answer 11

• PCR swabs and paired serology
• ensure good vax tachnique (at night)
• ensure correct vaccines are used at correct time

Question 12

What is mycoplasma? Clinical signs?

Answer 12

• 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

Question 13

How is mycoplasma transmitted

Answer 13

• 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

Question 14

What causes peritonitis

Answer 14

> 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

Question 15

Worm Tx

Answer 15

• Flubenvet in feed LIC 7d
• Solubenol in water LIC 7d
• Flimabo in water LIC 7d
• Panache Aquasol LIC 5d

Question 16

Worms

Answer 16

> 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

Question 17

What is the most common ectoparasites affecting chickens?

Answer 17

> red mites

• v common
• nocturnal
• think fleas!!!
• visable to naked eye
• life cycle can be 10d in warm weather
• can live 2y without feeding

Question 18

Tx red mite

Answer 18

• dichromatious earth

- introduce other bigger mites ? Echo

Question 19

Signs of underperformance in broilers

Answer 19

• underweight (usually measured weekly or daily!)
• reduced feed and water intake
• clinical symptoms

Question 20

Broiler life cycle

Answer 20

• 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

Question 21

Outline broiler systems

Answer 21

• 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

Question 22

Issues with drinkers

Answer 22

• raise up nipples as birds grow
• should drink at 45* angle
• otherwise litter will get wet and pododermatitis ensues

Question 23

Diseases in broilers

Answer 23

• IB
• IBD (gumboro)
• COCCIDIOSIS main dz
• enteritis/dysbacteriosis

Question 24

What is IBD

Answer 24

> 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

Question 25

Prevention IBD

Answer 25

Vax @ 18, 24, 28 d | - broilers only, doesn't affect layers

Question 26

Coccidiosis

Answer 26

- 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)

Question 27

Cocci control

Answer 27

- coccidiostats ionophores - chemical coccidiostats (baycox, ampolium, NOT VIRKON) - cleaning houses to kill oocysts - burn barn floors (can be more effective than chemicals)

Question 28

Enteritis 2 stages

Answer 28

``` > 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 ```

Question 29

How does the pyramid of poultry production work?

Answer 29

- 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)