Gauteng Smallholder December 2015-January 2016 | Page 51

POULTRY

Keep your chickens cool in a heatwave

T

he recent heatwaves in
Gauteng highlight the
likelihood of extreme
warmer temperatures
throughout the summer
season, which can be stressful
to livestock, and especially to
poultry confined to coops and
broody houses, most of which
are constructed of, or at least
roofed with, heat-trapping
galvanised iron.
Chickens are warm-blooded
animals with a body temperature between 40,6°C to
41,7°C. When they start to
feel hot, they cool themselves
down by panting, which is
effective. But if the temperature rises, the birds pant more
and so their respiration rate
increases. As they inhale and
exhale faster and faster, the
effort increases their body
temperature. When the body
absorbs or produces more
heat than it can get rid of, the
result is a serious condition
called hyperthermia, or heat

stress.
Symptoms of heat stress are:
K panting, with beak open,
K lying around with wings
outstretched,
K no interest in eating,
K slow response to stimuli,
unresponsive.
Persistent heat stress affects
the bird's metabolic processes, including nutrient
digestion, leading to poor
weight gain and a low feed
conversion ratio. With
prolonged panting, broilers
become dehydrated and
experience a rapid loss of
carbon dioxide from the
blood and tissues, as this gas
is exhaled during panting.
Rapid carbon dioxide loss
changes the blood, reducing
the amount of minerals
(including calcium) it can
carry through the body. The
increase in body temperature,
coupled with the change in
the composition of the blood,
eventually leads to the

collapse and death of the
birds.
If your chickens are kept in a
coop, you should aim to
maintain a temperature range
of 15 to 33°C.
There are a few things that an
owner can do to keep
chickens comfortable during
hot weather.
Sufficient supplies of water
are necessary for a couple of
reasons. Obviously all living
creatures need water to
survive. Howe