Light is essential for egg production in layer chickens. The length and intensity of light impacts the release of hormones from the pituitary gland that stimulate egg production. Different light sources like incandescent, fluorescent, and mercury vapor bulbs are used in poultry houses. Proper lighting installation and a cleaning schedule helps maintain sufficient light intensity levels. Commercial layer operations follow lighting programs to optimize egg production depending on whether the flock is in-season or out-of-season. In-season flocks are exposed to natural day lengths while out-of-season flocks require supplemental lighting to achieve target day lengths.

1. PREPAREDBY
Dr MuhammadAshiq Toor
DVM , B s c (Zoology)
Islamia University of Bahawal Pur (IUB) (2010 – 2015)
+92-344-499-7375
+92-300-364-2402
Light requirement in layer
Farming

2. Role of light
on egg
production
The egg production is
associated with the length
and intensity of the light
Light
anterior lobe of
the pituitary
gland
GnRH FSH,
LH

3. Terms regarding light
The lumen is defined as
the rate at which light
falls on a square foot
area surface which is
equally distant one foot
from a source whose
intensity is one candela
Lumen

4. 1 ft
1
f
t
1 ft
lumen

5. Foot candle
A foot candle is defined as
the intensity of light striking
each and every point on a
segment of the inside
surface of an imaginary one-
foot radius sphere with a one
candlepower source at the
center

6. 1 ft
Foot candle

7. Lux
A lux of light intensity is
equal to one lumen per
square foot
1 foot candle = 10.76 lux

8. TYPES OF LIGHT
There are four common light types used in poultry
houses are
Incandescent – Cheapest; necessitates reflectors,
short bulb life (750-1000 hrs)
Fluorescent – 3 to 4 times more efficient than
incandescent
bulbs; 10 times longer life than incandescent bulb
Mercury vapor – Long life (24,000 hrs); requires
several minutes to warm up; cannot be used in
houses with low ceilings.

9. Light Sources and Their
Efficiencies

10. THE MANNER IN WHICH LIGHTS ARE
INSTALLED IN THE POULTRY HOUSE
The distance between bulbs should be 1½ times the distance
from the bulb to the bird level
The distance from the bulbs to the outer edges of the house
should be only ½ the distance between bulbs
In cage system, the bulbs should be placed in such a way that
their rays fall on the feed and on the birds
Clean reflectors increase the light intensity at bird level by 50%,
compared with no reflector
Avoid cone shape reflectors since they confine the light rays to
limited area. Better to use flat type reflector with rounded edge
In case of deep litter system, the bulb is to be placed at 7-8’
height whereas in cage house, keep in aisle

11. CONTI…
Avoid hanging bulbs by a cord in open
houses
Very dirty bulbs emit about 1/3 less
light than clean bulbs.
Light bulbs should be cleaned once in
two weeks.

13. LIGHTING PROGRAM FOR COMMERCIAL
LAYER

14. LIGHT EFFECTS DURING GROWING PERIOD
Decreasing the length of light day during
growing period will lead to
Increase the age at sexual maturity
Increase the number of eggs laid during the
first half of the egg production (but not in total
number of eggs laid)
Increase the size of the first eggs produced

15. LIGHT EFFECTS DURING LAYING
PERIOD
Birds reared under increased day-light produce more
eggs due to the release of FSH and LH from the
pituitary
1 ft candle light intensity is needed in layer houses
 In multi-deck cage system, minimum of 0.5 foot
candle light intensity is needed at the lower deck
 For maximum egg production, 16 hours light is
needed during peak egg production period
Reducing photoperiod during laying period seriously
affects egg production

16. In-season
flocks
Those birds grown during a
period when the length of the
natural light day is decreasing, at
least during the last part of their
growing cycle are called in-season
flocks
As a general rule, chicks
hatched between August 31st and
March 1st

17. Out-
season
flocks
Chicks hatched between February
28th and September 1st are called
out-season flocks since their
growing period falls on increasing
light-day

18. light programs in open-sided
houses
In-season
flock
No artificial light is needed
up to 20 weeks At 20
weeks of age increase the
light to 13 hours.
 Then add 1 hr per week
until it attains 16 hours light.

19. Out-
season
flock
i) Determine the length of the
longest natural light day before
the pullets reach 20 weeks of
age. Maintain this period of
daily light hours from the 3rd
day until 20 weeks by
supplementing artificial light
with natural light. Then
increase 1 hour of light at this
stage and increase 1 hour every
week until it reaches 16 hours
total light period

20. Determine the total natural day-light hours
when the pullets reach 20 weeks of age. Then
add 7 hours. This represents the length of the
light day from the 3rd day. Thereafter reduce the
length of light day by 20 minutes per week. At
20 weeks of age increase the length of the light
day by 1 hour. Then increase 1 hour per week
until it attains 16 hours light per day.
conti