Consist of:

  • Shell
  • Air space.
  • Egg white (Albumen).
  • Chalaza
  • Shell membrane.
  • Yolk

The shell.


  • Made of calcium and phosphorus.
  • Gives the egg its shape.
  • Provides protection to the inner contents.
  • Porous thus allow gaseous exchange.

 Shell membrane.


  • Forms inner lining of the shell.
  • Air trapped between the two membranes is used by the developing embryo.

Albumen(Egg white)


Divided into four parts.

  • Chalaza and chalaziferous membrane.
  • Thin albumen.
  • Thick albumen.
  • Outer thin albumen.


Serves as a food reserve for the developing chick.


3% of Albumen.

Hold the yolk allowing the yolk to move the germinal disc always to the top position.

The yolk.


Contains food reserve for the developing embyo. Rich in vitamins, fats, minerals and proteins.

Incubation of eggs.

Embryonic development of a fertilised egg into a chick.

Selection of eggs for incubation.


  1. Should be fertile.
  2. Should be of medium size 55-60 grams in weight. Lighter or heavier weight lowers hatchability.
  3. Should have smooth shells. iv. Should be oval in shape.
  4. Free from any cracks in the shells.
  5. Should be clean to ensure that pore remain open.
  6. Should not have any abnormality e.g., blood spots, meat spots or double yolk. viii. Should be fresh that is collected within one week.


Egg candling.

Method of examining internal conditions of an egg for abnormalities by looking at it against a strong light in a dark room.

What is observed during candling? 

  1. Size of air space (cell)
  2. Whether the egg is fertilised (germinal disc will be seen as a black spot) or not.
  3. Whether the yolk has air cracks. iv. Whether the egg shell is broken.
  4. Whether the shell is very porous.

First candling 5th and 7th day to check for fertility (presence of blood veins or clear)

18th day to confirm presence of a chick.

Method of incubation.

Natural incubation.

Signs of broodiness.

  1. The hen stops laying.
  2. Continuous staying of the hen in the laying nest after laying.
  • Hen produces a characteristic sound and is aggressive when approached in the nest. iv. Hen plucks off her feathers to use in incubation nest.
  • Broody hen should be dusted with appropriate insecticides to rid her of parasites eg stick fast fleas.
  • Provide bedding (saw dust, wood shaving) to help maintain warmth in the nest.
  • Keep the nest in well ventilated place.

Advantages of natural incubation.

  1. Less laborious as there is no need of turning of eggs and checking temperatures.
  2. Little skills required. iii. Margin is risk is reduced.

 Disadvantages of natural incubation.

  1. Only a few chicks can be hatched at a time by one hen.
  2. One cannot plan when to incubate.
  3. Diseases and parasites spread to chicks after hatching if the hen is infected. iv. Hens can only be used when broody.

 Artificial incubation.

Providing all the necessary conditions for hatching eggs are provided artificially in an incubator.

Conditions necessary for artificial incubation.


Should be 37.5-39.4 degrees Celsius.

Lower or higher temperatures would kill the developing embryos.

Fresh air (ventilation)

Ventilation facilitates gaseous exchange and helps to control humidity.

Oxygen is necessary for embryonic development.

Relative humidity.

Should be about 60%.

Low humidity. Causes embryos to lose moisture and die.

High humidity. Lowers hatchability and leads to production of bigger chicks that look marshy.


Egg turning.

To avoid germinal disc sticking onto the egg shell causing embryonic mortality.

Wrong turning may result in breakage of blood vessels.

Advantages of artificial incubation.

  1. Many chicks can be hatched at one time.
  2. It is possible to plan when to hatch chicks.
  3. Under good management, parasites and diseases are not transmitted to chicks.

Disadvantages of artificial incubation.

  1. Incubator is expensive to buy. High capital investment is required.
  2. More labour demanding.
  3. Requires more skills than natural method.
  4. High risk involved.

Sources of chicks.

Factors to consider in sourcing chicks.

  1. Reputation of the supplier.
  2. Time taken during transit from hatchery to the farm.
  3. Type of chicks available or required such as breed desired, size of chicks, sex of the chicks.


Rearing of chicks. There are two methods.

  • Natural brooding.
  • Artificial brooding.


Requirements in an artificial brooder.


Should be placed on the floor to maintain warmth and absorb moisture.

Fresh air.

Holes should be made on the brooder for ventilation but should not allow draught into the brooder.

Heat source.

Wire guard round the heat source prevents chicks from being burnt.


1st week 32-35

2nd week 29.7-32.

3rd week. 26.6-29.7

Brooder should be lighted to allow chicks to see food and water.

Too much light blinds chicks and influence toe-pecking.



Should be clean to reduce infection.

Should discourage chicks from defecating on the feed and should be impossible to tilt.,


Should have pointed tops on which the chicks cannot perch.

Should be clean always.

Shape of the brooder.

Should be round in shape because corners encourages overcrowding causing suffocation.

Rearing of growers. 

Green vegetation should be provided to keep them busy.

Provide soluble grit/oyster shell to provide calcium and aids in digestion of food in the gizzard.

Feed them on growers mash ad lib.

16th week introduce layers ‘mash gradually.

Growers mash contains 16-17% DCP

Rearing of layers.

give clean water at all times.

Green leaves should be provided to keep them busy and prevent cannibalism.

Culling of hens that do not lay should be done.

Provide soluble grit to encourage strong shelled eggs and efficient digestion.

Layers mash contains 14-16% DCP.


Rearing systems.

Factors determining choice of system.

  1. Land availability.
  2. Topography of the land, to facilitate easy drainage.
  3. Availability of labour.
  4. Capital availability.
  5. Knowledge of the farmer.
  6. Availability of market.

Categories of rearing systems.

Extensive systems.

Semi-intensive systems.

Intensive systems.

 Free range.

Birds are allowed to move freely in a fenced ground which has a simple house to provide shelter at night. Laying nests are also placed in the house.



Land must be large, well-drained with trees for shade.

External fence should be established for preventing straying of birds


Land should be portioned to allow rotation. This reduces diseases and parasite build up.


This provide shelter and an area for laying nests.


  1. Cannibalism and egg eating are reduced because birds are free within the run.
  2. Birds have plenty of exercise thus helping to keep good health. iii. No need of providing grit as birds can pick it from the soil.
  3. Less feed is used as birds pick insects and grass.
  4. Manure is evenly spread to the runs helping vegetation to regenerate. vi. Requires low capital outlay for simple perimeter fence and shelter provision.


  1. Requires large tract of land.
  2. Birds can be stolen or eaten by predators.
  3. Eggs get lost in the runs. iv. Difficult to have close supervision on individual birds.
  4. Range area may become contaminated with diseases and parasites.
  5. Breeding programme is not easy to follow.
  6. Birds may cause damage to crops if perimeter fence has not been properly constructed.


Fold system.

It is a semi-intensive system.

Birds are confined in small portable structures called arks/folds.

One third of the fold is roofed to provide shelter.

Folds should be moved daily to a fresh ground to reduce build-up of diseases, provide fresh grass, allow spread of manure and avoid accumulation of droppings.

Advantages of fold system.

  1. Manure is evenly spread in the field.
  2. Less feed is used because the birds eat grass.
  3. Reduces build-up of parasites and diseases.


  1. Few birds are kept per fold. Expensive to keep many birds.
  2. Laborious in moving the folds daily.
  3. Difficult to keep individual egg production records. iv. Folds are not long lasting.

Intensive systems.

Deep litter.

Birds are totally confined in a house and stay indoors. All facilities are provided in the house (feeding and watering troughs, nest boxes and perches)



Should be well drained.


The roof should be leak proof.

The leeward side should be open from 60-90 cm above the ground and covered with a wire mesh for ventilation.

Floor should have litter to keep the floor warm and absorb moisture.

Frequent turning of litter to mix droppings and prevent caking.

In introducing new litter, mix it with the old to introduce bacteria that helps it to rot.

Litter should be 15-30 cm deep.

Feeders and waterers.

Should be enough and clean placed randomly to avoid overcrowding in one area.


Roosts and perches. 

Roosts are timber frames where birds perch to rest. They should be moveable to prevent accumulation of droppings causing dampness.


  • They are laying boxes.
  • Should be large enough to accommodate the bird comfortably.
  • Should be dark to discourage egg eating and cannibalism.
  • Provide soft dry grass/wood shavings to prevent egg breakages.

Advantages of deep litter system.

  1. Many birds can be kept in a small area that is, it allows a high stocking rate.
  2. Labour requirements e.g. collection of eggs, feeding and turning litter is low.
  3. Can be used to rear breeding stock.
  4. Birds are safe from predators and thieves because they are indoors.
  5. There is fast accumulation of manure.
  6.  There is no loss of eggs. 


  1. High incidences of cannibalism, egg eating, feather plucking and toe pecking.
  2. There is likelihood of pests and disease accumulation in the litter.
  3. Individual records of egg production per bird is not possible due to common laying nests.
  4. Litter may be difficult to find in some areas.
  5. Eggs may become dirty if laid on the floor or if laying nest are not clean.
  6. Contamination of feed hoppers and waterers by litter is common.

Battery cage system.

System whereby birds are confined in cages throughout their laying period.

Cages are made of wire mesh. Should allow space of 0.2M2 /bird.

Water troughs and feeders are fitted along the front sides of cages.

Cage floor should be slanting to allow rolling of eggs to the tray.

 Advantages of batter cage system.

  1. Higher egg production due to less energy wastage by the birds.
  2. Accurate eggs records can be kept because it is easy to know which bird has laid.
  3. Cannibalism and egg eating are controlled.
  4. Eggs are clean because hens do not step on them.
  5. The system can easily be mechanised.
  6. Birds do not contaminate food and water.
  7. Handling is easy as hens are restricted to a small place.
  8. Broodiness is discouraged as the birds do not reach the eggs.
  9. High stocking rate.
  10. Sick birds can be detected and isolated for treatment.
  11. Low labour requirements.


  1. Requires high initial capital.
  2. Requires high level of management.
  3. In case of disease outbreak, spreading is very fast.
  4. Birds do not have enough room for exercise.
  5. Not suitable for brooding purposes and rearing of chicks.
  6. Birds develop bruises on combs, breast and toes as they stick their necks out to eat and walk in the cages.

 Feeding layers.

Layers mash (11-12% protein) is introduced at 4 ½ months. It is rich in calcium and phosphorus required in egg shell formation. Feed 120 grams per day per bird.

Oyster shell and limestone improves the quality of the shell.

Feeding broilers. 

High vitamin and protein feeds should be given.




Any cause of discomfort to the birds.

Causes of stress in birds.

  1. Any sudden change e.g. change of feed.
  2. Strangers and predators like mongoose in the bird’s house.
  3. Poor handling of birds e.g. during vaccination, culling or debeaking.
  4. Sudden noise e.g. thunder, passing tractors.
  5. Sudden change of weather.
  6. Diseases and parasite infestation.
  7. Inadequate food and water.

 Control measures.

  1. Keep the poultry house quiet by building it away from the road.
  2. Insulate the poultry house to maintain uniform temperatures.
  3. Control diseases and parasites.
  4. Change of routine must be gradual.
  5. Provide enough feed and water.


Abnormal behaviour.

Egg eating.


  1. Presence of broken or soft-shelled eggs.
  2. Bright light in the nests allowing birds to see the eggs.
  3. Inadequate laying nests forcing birds to lay eggs on the floor.
  4. Inadequate minerals e.g. calcium in the diet.

Control measures.

  1. Collect eggs regularly.
  2. Make laying nests dark.
  3. Feed birds on a balanced ration.
  4. Debeak perpetual egg-eaters.
  5. Supply green leaves to keep birds busy.
  6. Scatter grains in the litter to enable the birds to scratch for them thus reducing idleness.


Condition where the birds peck each other. May result in death of large number of birds.

Causes of cannibalism.

i. External parasites.

As birds remove parasites from combs of other birds they cause injury that results in blood coming out of the wound making birds peck on the wound.

ii. Overcrowding

Makes birds see each other closely and it is easy to detect something to peck at.

iii.Bright light.

Makes toes of chicks shine, resulting in toe pecking.

iv.       Prolapse.

When the cloaca does not retract after laying of egg thus the cloaca is pecked at by others.

v. Mineral deficiency.

Makes birds to look for alternative source of the minerals.

vi.  Introduction of a new bird in a flock.

Causes fighting resulting in cannibalism after an injury. 

 Control measures.

  1. Avoid bright light in the house.
  2. Avoid overcrowding by providing adequate spacing to the birds.
  3. Provide birds with balanced feeds.
  4. Birds should be kept according to age groups.
  5. Control external parasites.
  6. Keep birds busy by hanging green leaves or vegetables in the house.
  7.  Debeak hens that peck others.
  8. Cull perpetual cannibals.




Sorting and grading.

Factors considered.

  1. Cleanliness.

Clean eggs command highest price, wipe dirty eggs with damp piece of cloth.

ii.   Size of the egg.

Larger eggs fetch higher market prices than smaller eggs.

Pack eggs size wise that is, small, medium and large.

iii.      Candling quality.

Eggs of high candling quality are preferred. Fresh eggs have a small air space.

iv. Egg colour.

Some consumers prefer brown shelled eggs to white shelled eggs.

Packing of eggs.

Pack with the broad end facing upward to maintain gaseous exchange. This is because the broad side contains air space.



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