Broiler growth is greatly influenced by the climate within the poultry house. The first steps to optimizing the environment are to monitor actual conditions and compare them to standard levels, in order to determine what steps need to be taken to achieve optimal bird performance. Key environmental parameters that affect broiler performance include temperature, ventilation, feed quality, water quality, and light levels. Proper environmental management requires monitoring these parameters.

1. E
nvironment is one of the factors that affect the growth of the chickens
from the first day of their arrival on the farm. Management of the
farm is a collection of many actions and activities, preparing the
facilities for optimal bird growth. I would define management as the sum
and interaction of skills, knowledge and experience of the person in charge
of the farm to reach the target with a team.
Environmental management is the key to success, using some
instrumentation and equipment to help analyse the data collected and to
understand the information we have to make a correct decisions. Using state-
of-the-art computer control is the best way to manage a large farm but not
every grower can afford this level of sophistication and capital investment.
So, how can we manage the environment on a small or medium-sized
farm without spending much money? It can be done although doing
everything manually is time-consuming and needs some experience with
the use and calibration of instrumentation Mastering this job makes
monitoring easy.
I believe that many growers around the world have difficulties in using
new technology for a variety of reasons but it is important to understand
the basics of environment measurements and how to understand the
numbers and the graphs. I will try to use simple terms and easy to find
instruments.
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Temperature
One of the most important factors influencing feed conversion is the
temperature of the broilers' environment.
Birds are homeotherms (warm-blooded), i.e. they maintain a constant
body temperature regardless of the environmental temperature.
In a cool environment, broilers eat more feed but much of the energy is
used to sustain normal body temperature, not meat production. An
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Broiler growth is greatly
influenced by the climate within
the house. The first steps to
optimising the environment are to
monitor the actual conditions and
then to compare these with
standard or recommended levels.
That way, it will be clear what
steps to take in order to achieve
the best possible bird performance.
— Dr Dhia Alchalabi
optimum temperature allows
the birds to use nutrients for
growth rather than
temperature regulation.
Broilers consume less feed
and convert this feed less
efficiently at high
environmental temperatures.
The biological cooling
mechanisms that birds use
during hot weather also
require energy. Furthermore,
the metabolic processes that
occur during digestion cause
the body temperature to rise
further.
Ventilation
Ventilation and
temperature are interrelated.
Under most conditions,
increasing ventilation lowers
the house temperatures and
so brooders or heaters may be
required to keep the house at
the ideal temperature. Many
growers reduce ventilation
during cold weather to reduce
fuel costs but this is a mistake.
Clean, fresh air is just as
important to growing broilers
as fresh feed and water.
Ammonia and other toxic
gases build up in under-
ventilated houses during
the cooler months. Studies
show that feed conversion
may be adversely affected
(from four to seven points)
by ammonia levels of just 25
parts per million – a level
barely detectable by the
human nose.
Experts strongly
recommend that broiler
growers ventilate to remove
ammonia during winter.
Figure 1. Building dimensions needed for calculation

2. Ventilation requirements will vary depending upon
the tightness of housing, humidity, litter condition,
etc. A minimum rate of 0.003m3/bird/minute is
probably sufficient during the first week but should
be increased as the birds grow. If you detect
ammonia at any time, immediately increase the
ventilation rate to eliminate it.
Feed quality
The feed greatly influences feed conversion.
Growers may have little control over the
composition of the feed - since these are often
decided by the integrator's nutrition experts – but it
is important to maintain the quality of the feed once
it is put in the feed bin.
Water quality
Clean, fresh water is important to bird growth.
Broiler performance on farms with contaminated
water supplies is almost always below average. When
the contamination is eliminated, performance
usually improves. Closed watering systems can
improve feed conversion compared to trough or
bell-type drinkers because water in the latter
systems is exposed to dust, litter, feed and faecal
material and hence, pathogens. Any effort you
expend to provide clean water to broilers will result
in better feed conversion.
Light
Light levels in the broiler house can also influence
growth. Bright light (1-2 foot-candles) stimulates
chick activity and helps them locate feed and water.
After 10-14 days of age, light levels can gradually be
reduced to a level of approximately 5.4 lux in the
darkest areas. Low light levels keep the birds calm
and the reduced activity results in better weight
gains.
General management
Other important factors are litter management
and the control of rodents and insects. Monitoring
water temperature especially in summer is also
important.
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This checklist (Figure 2) been designed to be filled
out once or twice a week to compare the data during
the run. It can, of course, be modified to fit the
needs of the particular grower and his farm.
Building information is important to compare
houses in the same farm, because building
differences have an impact on bird performance. To
compare houses, their differences must be analysed
and understood their effect on which component of
the poultry farm is that effect.
Ventilation system is also fixed, but it needs to be
taken into consideration in analysing the building.
This part is the specification design of the system
and the maximum airflow achievable, which needs
to be compared with the actual situation. From this,
it is possible to make appropriate changes in the
ventilation rates.
Environmental information is the essential part
of this list. There are two temperatures and relative
humidity readings: the first one is the actual one; the
second gives temperature and relative humidity
recommended by the breeding company. Water
temperature can affect feed intake especially in
summer and it should be 10-12°C. In hot weather,
flushing the water pipes will help to keep the water
is cool as possible. The water pH should be 6-8.
Air speed at the inlets gives an indication about
the ventilation system performance, and it is needed
to calculate the airflow used in the house.
Static pressure is the key to achieve good
ventilation and right amount of airflow. Not
achieving this means there are problems either with
Environmental management What do we need to monitor the environment?
Digital thermometer with stainless steel tip
Digital relative humidity sensor
Air speed meter
Static pressure gauge range 0-25 Pascal
Light meter
Carbon dioxide and ammonia sensors
pH meter
Smoke stick or smoker machine (for air direction).
Data collection forms
Analysis of data

3. the building (cracks, infiltrations, holes) or with the
ventilation system. This should be fixed to save energy and
wasted effort. Carbon dioxide, ammonia and dust need to be
monitored to check that the ventilation system is working
properly.
Airflow calculations are essential to understand the
ventilation system performance. The airflow of each fan must
be calculated carefully and correctly. In the end, you will have
the airflow for each size of fan. First, it is necessary to fix the
static pressure of the house. To measure the speed of the air
leaving the fan, an average speed is required. A good airspeed
meter can do that easily, and the place to measure is
important (follow the arrow in Figure 3).
Management information is the last set of information
needed. It compares the performance of this flock with the
previous one, giving a good indication of the management skills
of the manager and what level of bird performance to expect. —
Dr Dhia Alchalabi, poultry environment consultant, New Zealand
Environmental management
Figure 2. Environment information check-list
Figure 3.Where to measure air flow
Building Targets
Orientation E-W / N-S / Other
Dimensions, m Length / Width / Height
Insulation (U), W/m2.°C Walls / Ceiling 0.7-0.8
Infiltration Very high / High / Low / No
Ventilation System
Fans Number and diameter
Air flow/fan, m3/s
Total air flow, m3/s
Fan location North / South / Tunnel / Combined
Inlets Number / Height / Length / Total area (m2)
Environmental conditions
Inside temperature, °C Measured / Standard
Relative humidity, % Measured / Standard
Water Temperature (°C) / pH
Inlet air Average speed at inlet (m/s) / Inlet area (m2)
Air flow, m3/s Calculated / Designed
Static Pressure, Pa 12-25 Pa
Air direction Up / Down
Carbon dioxide, ppm < 2500ppm
Ammonia, ppm < 15 ppm
Dust Level High / Low / None
Air flow measurements and calculations
Outlet Outlet area of the outlet (m2) / Average air speed (m/s)
Air flow Flow per fan (m3/s) / Number of fans
Total air flow, m3/s
Air flow, m3/s For birds of that age / Designed for that house
Flock management information
Age, days
Bodyweight, g
FCR
Mortality, %
No. of birds
Feed type Starter / Grower / Finisher