Poultry chicks feeding. The water and feed equipment and the entire
surrounding of the brooder room must be kept clean and free from all
contamination to keep away diseases. FILE PHOTO | NATION MEDIA GROUP
By DR JANE N. MAINA
Every farmer desires 100 per cent survival of chicks once he or she
has bought and put them in a brooding house. Losses will, however,
almost always occur especially during the first two weeks of life.
A
mortality of 1-5 per cent may be considered normal, but anything above 5
per cent is abnormal and requires immediate intervention to stop
further losses. Indeed some of the causes can actually wipe out the
entire flock.
Some of the common causes of mortality in brooding chicks include:
Genetic Factors
There
are many lethal gene mutations in birds, most of which cause death
during the incubation period. A few, such as congenital loco and
congenital tremors will cause death of chicks within a week of hatching.
To prevent this, farmers are advised to purchase day old chicks from reputable firms who select against such genes.
Management Factors
The most common errors that famers commit include:
High brooding temperatures
These result into two major problems, namely,
- Dehydration
The
body of young chicks comprises of about 70 per cent water. If
temperatures remain continuously high, it results in loss of water from
the body leading to dehydration.
A water loss of about 10 per cent will cause death due to circulatory failure.
- Pasting
This
is when high temperature in the brooder house causes pasting or
sticking of faeces around the vent leading to blockage and ultimately
death of chicks.
Low brooding temperature cause chilling and
pneumonia which kills chicks in high numbers. Dead chicks on post
mortem show pale to blue lungs in colour.
Low brooding temperature
makes the chicks to huddle together to keep warm and maintain body
temperature. This further leads to smothering and death.
To
prevent the effects of temperatures, a farmer should adjust the brooding
room temperature 24 hours before putting the chicks in the brooding
room and during the brooding period.
A farmer should also try to
maintain the normal recommended temperature throughout the brooding
period and evenly in the brooding areas.
Feed related factors include
Feed
poisoning such as fungal (mould) contamination or feed contaminated by
toxic substances especially tannin found in saw dust and excess salt in
water as well as toxic gases (Ammonia, carbon monoxide and carbon
dioxide).
This should be avoided through use of proper feeding and
use of clean water as well as proper litter management with regular
mixing and removal to avoid accumulation of toxic gases in the brooder
room.
Adequate ventilation in the house is also very important.
Diseases
Newly
hatched chicks do not have a high immunity level. If hygiene is
therefore, not maintained, a number of diseases responsible for early
chick mortality will thrive.
Among the most prevalent of these diseases are:-
Omphalitis
Also
referred to as ‘mushy chick disease’ or ‘navel ill’, this is an
infection of the navel characterised by inflamed skin in the navel area,
soft, flabby and distended abdomen, pasting of the vent and foul smell
on the carcass on opening due to unabsorbed yolk. Affected chicks appear
depressed with drooping heads.
This is a bacterial disease and can spread very fast becoming responsible for high losses in the flock of chicks.
Pullorum
This
is an acute infectious and fatal bacterial disease of chicks
characterised by ruffled feathers, white diarrhea, laboured breathing,
chirping and death. It is also common to find dead chicks without
showing any signs of disease.
Salmonellosis
This
is a condition referring to a group of acute rapidly spreading diseases
affecting all ages. It is characterised by rise in body temperature,
septicemia (presence of infectious oroganisms in blood), omphalitis,
hepatitis (inflammation of the liver), enlargement of spleen and death.
When it affects young chicks, it can be responsible for a very high death rate in the brooder room.
Colibacillosis
This
is a serious and acute bacterial disease affecting the blood system and
can affect all ages of chicken with high prevalence and mortalities in
newly hatched chicks.
Strict bio- security, or hygiene is the one
major method of preventing the above diseases. The houses, water and
feed equipment and the entire surrounding of the brooder room must be
kept clean and free from all contamination.
Other factors to be considered are:
•
Floor, water and feeder space must be adequate to avoid overcrowding,
starvation and dampness of the litter which facilitates multiplication
of pathogenic micro-organisms and further deaths.
• Proper
handling of chicks during vaccination and other procedures to avoid
injuries which predispose chicks to contamination and subsequent
infections.
•Maintaining proper humidity to avoid dampness in the
brooder room. Dampness facilitates accumulation of toxic gases and
growth of infectious micro-organisms.
• Construction of brooder houses should also be proper to keep away predators such as rats, dogs and cats.
•
Proper ventilation is necessary to regulate temperature and remove
carbon dioxide, ammonia, other gases, moisture, dust and odour. Fresh
air should be introduced uniformly, mixed well with house air, and
circulated properly throughout the brooder house.
• Light is an
important factor during brooding because chick activity is greater in
bright light intensity than in low light intensity. During brooding the
light should be at the brightest intensity to encourage chick activity
assisting them to locate feed and water. Once they learn where feed and
water are located (around 7 to 10 days of age), the light intensity and
duration can and should be reduced.
***
Dr. Jane N. Maina is Veterinarian, Faculty of Veterinary Medicine and Surgery
CREDIT: NATION MEDIA
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