The document discusses environmental factors that affect egg production in laying hens. It identifies 11 key factors: 1) climate, 2) nutrition, 3) shelter/housing, 4) health, 5) management, 6) lighting schedule, 7) feed, 8) age, 9) body weight, 10) laying house, and 11) vaccination and disease control. Proper management of these environmental factors through practices like providing adequate shelter, feed, lighting schedules, and vaccination is necessary to maximize egg production and profitability over a hen's 52-56 week production cycle.

2. Typically, a layer’s production cycle lasts just over a year(52-56 weeks).
During the production cycle many factors influence egg production,
therefore, the cycle must be managed effectively and efficiently in
order to provide maximum output and profitability.
 Environment may be visualized at the surroundings in which a bird is
placed or conditions to which it is subjected.
 The expression of the potentialities of an animal including the
Avians ,is the sum of the responses of the animal Or bird to their
genetic makeup and their interaction with the environment in which
they are placed
ENVIRONMENTAL FACTORS AFFECTING EGG
PRODUCTION

3. The components of environment
 1. climate
 2. nutrition
 3.shelter/housing
 4.level of health
 5.management
All the above factors combining affect the egg production
1.Breed:
The breed of the laying bird influences egg production.
Management and feeding practices , however, are the key determining features for egg production.
2.Mortality rate:
mortality rate may raise due to disease, predation or high temperature.
 The mortality rate of small chicks (up to 8 weeks of age) is about 4 %;
 that of growers (between 8 & 20 weeks of age) is about 15%;
 and that of layers (between 20 &72 weeks of age) is about 12%.
 The average mortality rate of flock is from 20 to 25% per year.

4. 3. Age:
birds typically begin production eggs in their 20 or 21 week and continue for slightly over a year.
This is best laying period and eggs tend to increase in size until the end of the egg production
cycle.
Chick factors
 Layers are usually kept for 52 weeks. After this period, they undergo a stage called moulting
where they lose their feathers and stop producing eggs. Egg production will start again in the
second laying period after moulting, but the eggs will be bigger, shells thinner and production
lower.
 Older birds produce eggs with thin shells.
 Indigenous chickens do not lay as many eggs when compared to commercial layers.
4. Body weight:
in general, optimum body weight during the laying period should be around 1.5 kg , although this
varies according to breed.
 Underweight as well as overweight birds lay eggs at a lower rate.
 Proper management and the correct amount of feed are necessary in order to achieve optimum
body weight.

5. 5.Laying house:
the laying house should be built according to local climatic conditions and farmer’s
finances.
A good house protects laying birds from theft, predation, direct sunlight, rain, excessive
wind, heat and cold, as well as sudden changes in temperature and excessive dust.
if the climate is hot and humid, for example, the use of an open house construction will
enable ventilation. the inside of house should be arranged so that it requires minimum
labor and time to care for the birds.

6. TYPES OF LAYING HOUSES
Open house type
Housing for hot - arid climates

7. Moveable type housing

8. 6.Lighting schedule:
 egg production is stimulated by daylight; therefore, as the days grow longer
production increases.
 In open houses , found commonly in the tropics, artificial lighting may be used to
increase the laying period. When darkness falls artificial lighting can be introduced
for 2 to 3 hours, which may increase egg production by 20 to 30 %.
 In closed house , where layers are not exposed to natural light, the length of the
artificial day should be increased either in one step, or in a number of steps until
the artificial day reaches 16 to 17 hours, which will ensure constant and maximized
egg production. Figure 1 - Lighting schedule

9.  Effective day light should never decrease during the laying
period.
 When the lights are off, chickens do not eat and this results in
low egg production. Lights should be checked regularly and
cleaned so that they do not get dimmer.
 Bulbs should be changed when necessary
 Exposure to light for less than the minimum time required
results in a drop in egg production.
 When chickens are exposed to too much light, they reach
sexual maturity at an early stage and they lay very small eggs.

10. 7.FEED
feed-range hens will produce more meat and eggs with supplemental feed, but
only if they are improved breeds or crossbreeds. The selection of local hens is done
on the basis of resistance and other criteria rather than feed utilization for
production.
Fresh and clean water should always be provided, as a layer can consume up
tone-quarter of liter a day.
FEED-RELATED PROBLEMS
Not enough drinking water
Clean and cool water must always be available to avoid heat stress. Lack of
water results in reduced egg production.
No feed or decreased feed intake
Chickens tend to eat less when the feed is not tasty or when they are stressed
because of environmental temperatures, especially when it gets too hot. Feed
should be available at all times.
When chickens are not well fed, egg production decreases

11. Low calcium in the feed
• This result in few and smaller eggs, soft-shelled eggs, shell-less eggs, cracked eggs,
eggs losing colour and hens having leg problems.
• If calcium deficiency is suspected, take a feed sample to the laboratory to check the
calcium level.
• Commercial rations have calcium added. When mixing your own ration make sure that
calcium added is 3,5 %.
• If calcium deficiency is a problem, limestone grit should be given as a top dressing at
at least twice a week at 5 gm /bird.
Low salt in the feed
• This results in a sharp decrease in egg production.
• Chickens will also start pecking each other and eating feathers
• If salt deficiency is suspected, a sample of feed should be taken to the
laboratory to check the level of salt.
• Take care when mixing your own chicken ration at home. Add the required
quantity of salt, which is 0,4 %.

12. 8.Culling:
culling is the removal of undesirable(sick and /or unproductive) birds, from the
flock. There are two method of culling:
. Mass culling, when the entire flock is removed and replaced at the end of the
laying cycle; and
. Selective culling, when farmer removes individual unproductive or sick birds.
Culling enables a high level of egg production to be maintained, prevents feed
waste on unproductive birds and may avert the spreading of diseases.

13. 9. Climate: the optimal laying temperature is between 11 and 26 degree centigrade.
A humidity level above 75% will cause a reduction in egg production in egg laying.
Temperature and its effects on egg production
When the temperature raises above 28° C degree centigrade the production and quality of eggs decrease.
Seasonal temperature increases can reduce egg production by about 10%.
Temperature ( C ) effects
11-26 Good production
26-28 Some reduction in feed intake
28-32 Feed consumption reduced and water intake increased ,
Eggs of reduced size and thin shell
32-35 Slight panting
25-40 Heat prostration sets in ,measures to cool the house must be
taken
40 and above Mortality due to heat stress.

14. 10. Management factors:
effective and efficient management techniques are necessary to increase the productivity of the birds
and
consequently increase income.
This entails not only proper housing and feeding, but also careful rearing and good treatment of the
birds.

16. DISEASES
diseases
bacterial
metabolicviral
parasitic

17. 11.Vaccination and disease control:
diseases and parasites can cause losses in egg production.
Some of the diseases are as fallows:
.bacterial: tuberculosis, fowl typhoid
.viral: new castle,fowl plague
.fungal: aspergillosis
.protozoan: coccidiosis
.nutritional: rickets, perosis
Some of the parasites are:
.external: lice, mites
.internal: roundworms, tapeworms

18. Newcastle disease (NCD)
 NCD is a viral infection that can result in a mortality rate of 100 % in chickens.
 It also leads to a drop in egg production and quality.
Infectious bronchitis (IB)
 This is a rapidly-spreading viral infection of chicken characterised by respiratory signs.
 It also causes drop in egg production (up to 50 %) and egg quality.
 Egg shells are deformed.
There is a vaccine for this disease.
Epidemic tremor
 This is a viral infection that results in a drop in egg production.
 Layers are vaccinated on the thirteenth week of age. The vaccine is given in the drinking water.
Egg drop syndrome
 This is a viral infection that affects the reproductive organs of chickens.
 The signs are a drop in egg production, thin shells, soft shells and shell-less eggs.
 There is a vaccine available to prevent the disease.
 Layers are vaccinated on the sixteenth week of age.
 The vaccine is given in the muscle.
Other diseases causing a drop in egg production are salmonellosis, mycoplasmosis,
infectious laryngotracheitis and internal parasites (when the chickens are kept on the ground).

21. Vaccinations are administered to birds by
 injection,
 water intake,
 eye drops and
 spraying.
Clean and hygienic living quarters and surroundings may eliminate
up to 90% of all diseases occurences.
12.Collection of eggs:
frequent egg collection will prevent hens from brooding eggs or
trying to eat them and will also prevent the eggs from becoming
damaged or dirty.