There are enormous causes of early chick mortality. Whereas attempts could be made to diagnose the early chick mortality includes:
- Genetic causes.
- Managemental causes.
- Nutritional causes.
- Disease causes.
1. Genetic Causes:
Genetic cause is also important because there are 21 lethal mutations in the fowl. The lethal is more pronounced in homozygotes especially during 3rd week of incubation. The greater the abnormality caused by the lethal gene, the earlier the age at death. Most creepers die at 3rd or 4th day of incubation and most talpid embryos at 8th to 10th day. Sticky embryos die during the last 4 days of incubation and about half of the Naked chicks die during 2 or 3 days before hatching time, congenital loco is lethal within a week after hatching and congenital tremor kills 90% of the affected chicks within a month. If the eggs from a control and a carrier flock are incubated under the same conditions, the maximum possible difference of hatching will be about 25%.
2. MANAGEMENTAL CAUSES:
Managemental errors are most often seen to be the first cause of early chick mortality. Temperature, humidity, poisoning ets:
A) Effect of high brooding temperature High brooding temperature causes the following problems,
Dehydration: When the water loss from the body reaches above the 10% the chicks die. Actually the young chicks comprises 70% water. Due to high brooding temperature water loss become high resulting death.
Pasting: It’s the condition in which the feces are stalked around the vent area causing blockage of the vent which ultimately results in death.
B) Effect of low brooding temperature Low brooding temperature causes the following problems:
Chilling or brooding pneumonia: When the brooding temperature is low, chicks accumulate at a area near to light source, which cause suffocation resulting to pneumonic problems resulting death , where lungs become blue colored if examined carefully
Smothering: During low temperature chicks huddle together to maintain body temperature which results in smothering and death.
To prevent the problems of dehydration, pasting, chilling and smothering we should adjust the brooding room temperature 24 hours before putting the chicks in the brooding room and during the brooding period. Try to maintain the normal temperature throughout the brooding period and brooding areas.
C) Effect of poisoning Mortality due to poisoning is also high in young chicks such as:
Feed poisoning: Fungal contaminated feed and toxic material in feed causes feed poisoning .
Salt poisoning: Salt poisoning also causes mortality which is due to excess salt in drinking water and feed.
Gas poisoning: High concentration of different toxic gases also causes mortality .
Ammonia: It causes irritation of mucous membrane & eyes, low feed consumption, reduced growth rate, loss of cilia in the trachea , hemorrhages and death at level above 100 ppm, so its concentration should be less than 25 ppm.
Carbon monoxide (CO): CO combines with hemoglobin to form carboxy-hemoglobin which is unable to transport oxygen. The lethal conc. of CO is 2000-3600 ppm .
Carbon dioxide: If the conc. of CO2 goes beyond 30% ,it causes suffocation and death.
Tennin or Litter poisoning: The ingestion of toxic material like tannin in saw dust causes mortality.
D) Effect of injuries: If chicks are not handled carefully during various operations it causes injuries and death which are; sexing, vaccination, dubbing, debeaking.
E) Starvation: Young chicks do not have fat storage to fulfill body needs during starvation, so it results in death.
F) Less floor, feeder and waterer spaces: less floor space is another cause of mortality in chicks as overcrowding causes dampness of the litter material which become a suitable site for the multiplication of micro organism, causing, coccidiosis etc. Less feeder and waterer space causes starvation and death specially in young chicks.
G) High relative humidity High relative humidity in brooding house causes the dampness of litter material which facilitate the growth of micro organisms causing infections.
H) Predators If brooding houses are not properly constructed against predators they also causes mortality, e.g. Rat, Dog, Cat etc.
2. NUTRITIONAL CAUSES
A) Water: Water play an important role in maintaining the health and performance of the birds. It acts as a transport medium for nutrients and metabolic end products. It helps in maintaining deep body temperature during hot weather. Water play an important role in weight gain of broiler. Water fulfills the minor deficiency of mineral like Na, Cl, K etc. Imbalance and unhygienic water causes high mortality.
B) Effect of fat soluble vitamins deficiency: Severe deficiency of these vitamins (A, D, E & K) causes death, but minor deficiency causes cessation of growth, ruffled feather, lacrimation, rickets, encephalomalacia, exudative diathesis and anemia etc.
C) Effect of water soluble vitamins deficiency: Severe deficiency of these vitamins (B-Complex & C) causes death, but minor deficiency causes, loss of weight, poor feathering, poor growth, dermatitis, perosis, nervous signs and anemia etc.
If biosecurity measures are not maintained then there is a great chance of disease out-break, because the young chick lack immunity .
Omphalitis: This bacterial disease affects the chicks during and after hatching, spreads navel infection characterized by inflamed skin in the navel area, soft, flabby and distended abdomen, vent pasting, foul smelling on carcass opening, due to unabsorbed yolk.
Pullorum It is an acute infectious and fatal bacterial disease of chicks characterized by ruffled feather, white diarrhea, labor breathing, chirping and death.
SalmonellosisA group of acute rapidly spreading diseases affecting all ages characterized by rise in body temperature, septicemia, omphalitis, hepatitis, enlargement of spleen, arthritis and death.
Colibacillosis It is an acute septicemia disease caused by E-coli affecting all ages characterized by involvement of all systems, poor feed conversion and death.