What is a healthy hen?
Cracked/broken eggs:
Problem
- Large cracks and holes
- % in production: increases with the age of the hen.
- 1–5 % of total production
Causes
- Old birds (> 50–60 weeks)
- Mineral deficiencies or imbalance
- Saline water
- Diseases with ovary tropism
- High temperatures
- Mechanical damage during collection
Hairline cracks:
Problem
- Very fine cracks that require efficient candling
- % in production: varies with the age and the % of cracked of broken eggs
Causes
- Old birds (> 50–60 weeks)
- Mineral deficiencies or imbalance
- Saline water
- Diseases with ovary tropism
- High temperatures
- Mechanical damage during collection
- Infrequent egg collection
Star cracks:
Problem
- Fine cracks radiating outwards from a central point of impact
- % in production: varies with the age, 1–2 % of the total production
Causes
- Old birds (> 50–60 weeks)
- Mineral deficiencies or imbalance
- Saline water
- Diseases with ovary tropism
- High temperatures
- Mechanical damage during collection
- Infrequent egg collection
Shell-less eggs and thin shelled:
Problem
- No shell or very thin shell, very easy to break
- % in production: varies 0.5–6 %.
- High levels possible with pullets in early maturity
Causes
- Immature shell gland
- Disrupted deposition of calcium in shell
- Mineral deficiencies or imbalance
- Saline water
- Diseases with ovary tropism
- Mechanical damage during collection
- Infrequent egg collection
Sandpaper or rough shell:
Problem
- eggs with rough texture areas unevenly distributed over the shell
- % in production: the incidence should be < 1 %
Causes
- Diseases with ovary tropism and avian encephalomyelitis
- Disrupted egg oviposition or egg retention
- Sudden increase of light during lay
- Water shortage
Misshaped eggs:
Problem
- shell marred by at sides or body checks (ribs or grooves)
- % in production: can rise to 2 % at start of layand later almost disappear unless there is an issue
Causes
- Immature shell gland
- Diseases with ovary tropism
- Stress caused by frights and disruption
- Crowding
Flat sided eggs:
Problem
- eggs with rough texture areas unevenly distributed over the shell
- % in production: the incidence should be < 1 %
Causes
- Diseases with ovary tropism and avian encephalomyelitis
- Disrupted egg deposition
- Sudden increase of light during lay
- Crowding
Pimples:
Problem
- small lumps of calci#ed material on the eggshell
- % in production: around 1 % is common
Causes
- Old birds
- Excess of Ca
- Sudden increase of light during lay
- Crowding
Pinholes:
Problem
- small holes in the eggshell
- % in production: < 0.5%
Causes
- Old birds
- Mineral deficiencies or imbalance
- Damage caused by hen or sharp objects in cages or collection conveyor
Mottled or glassy shell:
Problem
- appears mottled at candling
- % in production: not usually undegraded unless the condition is obvious. Incidence varies
Causes
- High humidity at the farm
- Mineral deficiencies
- Crowding
- Diseases with ovary tropism and infection bursal disease in parent stocks
Albumen quality
Yolk quality
Blood spots:
Problem
- blood spots on the surface of the yolk
- % in production: incidence varies, 1–2 %
Causes
- Deficiencies in vitamin A and K
- Fungal toxins
- Continuous light programs or intermittent light periods
- Fright and disruption
- Avian encephalomyelitis
Meat spots:
Problem
- brown colored, pieces of tissue of the ovary or partially broken-down blood spots
- % in production: 1–3 %
Causes
- deficiencies in vitamin A and K
- Fungal toxins
- Continuous light programs or intermittent light periods
- Fright and disruption
- Avian encephalomyelitis
Pale yolks:
Problem
- the egg yolk doesn’t have the expected color
- % in production: incidence varies based on the issue
Causes
- Gut health issues
- Mycotoxines
- Liver damage
- Oxidation of the added pigments
- Wrong mixing of the pigments
