Basics

Question 1

Egg sizes

Answer 1

goose (grey, liver) : 155g, 8,7x 6cm wide
Duck (American pekin) 92g, 6.5x 4.5cm
Duck (khaki campbell) 55-65g, 6.5x 4.5cm
Muscovy duck 75-85g, 6,2x4,5cm
Chicken 50-70g, 5.5x4.2 cm wide
Quail: 8-10g, 3.2x 2.5cm wide

Question 2

Development of the egg

Answer 2

ovary
• yolk, 10-11 days
• colour: xanthophyll(can be altered by nutrition)
• germinal disc
• blood spot, meat spot (follicular or infundibular debris)
ovary duct
• infundibulum–insemination
• magnum – white (chalaza, exterior, middle and interior albumen) – 3 hours
isthmus – interior and exterior membranes
uterus
• shell – 19-21 - hours=> 70-200 pore/cm2 (0,03% of surface area)
• protoporphyrin pigment – genetic predisposition
• (Araucana breed: biliverdin, green and blue)
• cuticle (10nm glycoprotein)

Question 3

Embryonic development

chicken

Answer 3

embryonic stage (8-9 days)
• qualitative development (organogenesis)
• 2.-4. days are critical
foetal growth (10-21. nap)
• quantitative development
• 12-13. days the position is fixed
• 19.-21. days critical (a weak chick can not hatch)
Disturbances:
• layer flock health
-malnutrition, deficiencies
-infectious disease (in theory any of them)
-septicaemia (E. coli, Salmonella, Staphylococcus)
-AI, NDV, AMPV, IB
• technology in the hatchery
-hygiene, temperature, humidity, rotation

Question 4

Chick quality

Answer 4

• good body condition is very important
• criteria for poor condition:
• low body weight (chicken: <42 g)
• open navel
• omphalitis
(General signs of omphalitis
• calor• rubor• dolor• tumor
• functio laesa (does not absorb)• inflammatory discharge• serum• fibrin)
• yolk sac inside the body after day 19.
• after hatching it has to be absorbed
• Meckel’s diverticula remains

Question 5

Practical considerations

Answer 5

• unavoidable in some extent (1% bonus)
• common complaint (> 2% mortality until day
10)
• necropsy and bacterial culture in statistically
significant numbers

Question 6

Foot ulcer – pododermatitis ulcerosa

Answer 6

• litter quality problems
• maceration and/or mechanical trauma
• bacterial infection (E. coli, Staphylococcus sp.)

Question 7

Ammonia

Answer 7

• 20-50 ppm: respiratory edema, decreased resistance

* 50-100 ppm: keratoconjunctivitis, ulceratio

Question 8

Heat stress, heat shock

Answer 8

day-old chick 31 °C and 80% RH
• in daily cycle even 35 °C is well tolerated
(at night 25 °C)
• animal heat production
• rise of body temperature
(40,5°C - 41,7°C – 44°C)
• blood vessel dilute, serum exits=>pinpoint haemorrhages=>circulation collapse=>death
post mortem
• macroscopic
-hyperaemia, haemorrhages, edema, dilated heart
• microscopic
-haemorrhages, edema, heart muscle & renal parenchyma degeneration

Question 9

Differentiating sudden and high mortality

Answer 9

• Heat shock
• Hypoxia
• Intoxication• feed or gases (CO, ammonia)
• peracute inflammation
-ND, AI
-turkey: cholera, bluecomb/TCE
-duck: DP, DHV
-goose: Derzsy’s disease
macroscopic findings (if you are lucky):
• hyperaemia, haemorrhages
• edema
• dilated heart

Question 10

Result of necropsy in the modern poultry industry

Answer 10

• Regularly vaccinated parent flocks– maternal immunity
ND mandatory
IB, IBDV, CAV, MG, MD, SE/ST always
+ AMPV, AE, ILT, Pox + bacteria (Pasteurella, Riemerella, Avibacterium, ORT,
E. coli)
• Vaccination in the hatchery (80% in ovo)
• Vaccination on the farms (1-2-3 times)
>Relative immunity
>lesions obscure or absent
=><= high mortality is still a possibility

Question 11

Microbe definitions

Answer 11

Pathogenicity= microbe's ability to cause disease
Virulence= ability to multiply in body, inducing lesions
Infectivity= number of microbes needed to infect host
Infectiousness= ease with which microbe is transmitted between hosts
Invasiveness= measure of the ability to spread through cells/organs/etc