single comb of medium size. The egg shell is brown in colour while the flesh, skin and feet are yellow. The bird is a prolific layer and makes a good mother.
LOADING....
single comb of medium size. The egg shell is brown in colour while the flesh, skin and feet are yellow. The bird is a prolific layer and makes a good mother. 4. The Barred rock – Dual purpose This is a tail bird with a deep long square body. The barring (black parallel stripes of plumage) is uniform throughout the body with a grayish under colour. 5. New Hampshire red This is a hardy bird and an excellent layer which produces tinted eggs. It has a single comb of medium size. The flesh, feet and legs are yellow in colour.Poultry Keeping & Management
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Activity 3.2
1. The following birds are all poultry breeds except:
a) Quail
b) Parrot
c) Turkey
d) Chicken
e) Ducks
2. Which of the following characteristics are true of light poultry breeds? Tick the correct ones.
a) Nervous and get upset by sudden movements
b) They eat more,
c) Mature early and get into production earlier
d) They go ‘broody’ or try to incubate their own eggs
e) Are smaller in body hence cheaper to maintain
f) They have an inferior carcass
g) They are quieter
Compare your answers with those given at the end of this unit.
You now know the various chicken breeds available in Kenya and their characteristics. Next we shall discuss incubation practices.
Section 3.2: Incubation
Incubation is the process of keeping eggs under favourable temperatures in order to promote embryonic growth and the hatching of young chicks. Before we look at the process of incubation, let us look at the composition of a chicken egg.
Composition of a Chicken Egg
A chicken egg is made up of various parts as shown in figure 3.5 below:
The shell
The shell membrane
Albumen
Chalazae
Yolk.
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Figure 3.6: Diagram of a fertilized chicken egg
The Shell
This forms 12% of the egg and is largely made up of calcium carbonate which
makes it hard. It protects the interior parts of the egg and has pores that allow
gaseous exchange.
Shell Membranes
This is the inner lining of the shell. It has 2 membranes that separate at the broad
end of the egg to form an air space.
Albumen (egg white)
The albumen makes up 55% of the egg. It is a jelly-like, colourless fluid when
fresh.
It surrounds the yolk and serves as a food reserve for the developing chick.
Chalazae
These are 2 twisted cords which hold the yolk from both ends of the egg.
If the chalazae is broken the yolk shakes and is displaced from its normal position.
Yolk
The yolk makes up 33% of the egg. It is yellow in colour and spherical in shape. It
has a germ spot which develops into a chick. A fertilized germ spot is called a
plastoderm while an unfertilized one is called a plastodisa. The yolk contains
food reserves for the developing chick and is rich in vitamins, fats, minerals and
protein.
Qualities of Eggs for Incubation
Eggs for incubation should have the following qualities:
They should be fertilized
They should be of medium size i.e. about 55-60gms in weight
Should have smooth shells
Oval shaped
Not cracked
Clean to ensure that pores are open
Shell
Chalazae (dense protoplasm)
Inner
membrane
York
Air space
Germ layer spot
Outer membrane
Albumen
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Should not have abnormalities such as blood spots, meat spots, double yolk
etc.
Should not be more than 5 days old.
Egg Candling
Egg candling is a method used to check eggs for fertility and determine which ones
will hatch into chicks. It involves observing an egg through light rays, see figure 3.7
for the candling technique.
Figure 3.7: Candling technique
Candling Method
As you can see from Figure 3.7, candling is a simple method which you can do at
home using the following procedure:
Cut a small round hole on top of a cardboard box. The hole should be just
big enough to sit the pointed end of the egg
Place a torch inside the cardboard box just under the hole
Place the egg on the hole and turn on the light
You will be able to see if the egg is fertile. A fertile egg has blood veins and a
black spot inside the egg. Figure 3.8 shows you the results of candling.
a) Fertilised egg b) Unfertilised egg
Egg
Light source
Hole to place egg
Cardboard or
wooden box
Poult