Mesonet connection, 06/2013, v.4

              connec t ion
Poultry Stress Management
how long they need to run their fans,” Freking said. “This
helps to avoid the deadly combination of heat and humidity.”
Weather data is very important to help determine the need
and type of evaporative cooling system to use in an area.
The most crucial weather factors that help determine the
need for evaporative cooling systems is prevailing high
temperatures with high relative humidity.
According to Jim Donald, P.E.,
Professor and Extension Engineer
at Auburn University, “The goal
of evaporative cooling in a
tunnel house is to get inside air
temperature down to the range
(80°-84°F) where wind-chill cooling
can keep birds comfortable. The
relative humidity of air determines
the theoretical cooling potential
available. The most critical weather
factor in making evaporative
cooling system decisions is how
hot it gets for how long, and what
the relative humidity tends to be at these times. The higher
the temperature and the lower the relative humidity, the
more need for cooling and the more effective evaporative
cooling can be.”
Freking added, “The best thing about the Mesonet is all the
houses have to be designed based on local weather, so the
engineers rely on your products heavily.”
Volume 4 — Issue 5 — June 2013
www.mesonet.org
THE MESONET PROVIDES VITAL products to help
Oklahoma poultry producers monitor specific weather data.
High temperatures, humidity and dewpoint can all have a
negative effect on bird performance. Luckily, evaporative
cooling systems in tunnel ventilated broiler houses help with
this problem.
“Things have changed over the last ten years,” said
Brian Freking, OSU Southeast Area Extension Livestock
Specialist. “Twenty years ago, one
way they cooled the birds down is
by keeping track of temperature
and humidity. If it was 80 degrees
with 80 percent humidity, they
would start losing chickens. Now,
they have controllers in the chicken
houses, and they use a system
that is called tunnel ventilation.
It is a wind tunnel that pulls in air
from an opening and runs the air
through wetted cardboard, known
as evaporative cooling. So wind
speed is important as well. The
most efficient system can drop temperatures 20 degrees.”
Freking says it is also important to monitor dewpoint because
poultry houses need to stay dry inside. The Mesonet’s
Temperature/RH/Dewpoint Graph is a great tool to monitor
all three weather variables.
“Poultry growers can use your (the Mesonet’s) tool to figure
–by Stephanie Bowen
This particular research house at The University of Georgia Poultry Research Farm consists of two 100’ X 40’ environmentally controlled rooms. Exaust
fans are located in the end walls and a series of “european style” air inlets are located along each side wall. Evaporative cooling pads are located in a
plenum wall located approxiamtely 2’ from the building side wall. The plenum wall provides both cooling of the incoming air as well as light control.
The Mesonet’s Temperature/RH/Dewpoint Graph is
used in multiple areas in the agriculture industry.
For example, it is used during hay baling season.
These variables impact the hay’s moisture content
which is important to succesfully bale, and it
impacts the hay’s value as well. To view this graph,
visit www.mesonet.org, and click on ‘Agriculture’ in
the top menu. Then select one of the following from
the sub-menu:
Crop - Grass Hay or Alfalfa
Livestock - Poultry
Range/Forest - Rangeland or Forestry