Incubation method, Types of incubators and Seasonal hatching

Incubation methods

There are two main types of incubation:

1.Natural incubation 2.Artificial incubation

Natural incubation

The full incubation period for an egg, from laying to hatching, is 20 to 21 days.

During this time, a hen sits on her egg(s) and maintains a temperature of around 100 degrees Fahrenheit. This temperature is needed to ensure proper embryonic development.

The broody hen chosen for natural incubation should be large (to cover and thus keep more eggs warm), healthy and preferably vaccinated, with a good brooding and mothering record

Signs of broodiness are that the hen stops laying, remains sitting on her eggs, ruffles her feathers, spreads her wings and makes a distinctive clucking sound.

The hen keeps the eggs at the correct humidity by splashing water on them from her beak. This is a further reason for providing her with easy access to water.

Eggs initially need a very controlled heat input to maintain the optimum temperature of 38°C, because the embryo is microscopic in size.

As the embryo grows in size (especially after 18 days), it produces more heat than it requires and may even need cooling.

Moisture levels of 60 to 80 percent Relative Humidity (increasing during the incubation period) are important to stop excess moisture loss from the egg contents through the porous egg shell and membranes

A hatchability of 80 percent (of eggs set) from natural incubation is normal, but a range of 75 to 80 percent is considered satisfactory.

Artificial incubation

Artificial incubation of poultry eggs is an ancient practice.

The Chinese developed artificial incubation at least as early as 246 B.C.

These early incubation methods were often practiced on a large scale, a single location perhaps having capacity of 36,000 eggs

Incubation can successfully occur artificially in machines that provide the correct, controlled environment for the developing chick

Temperature regulation is the most critical factor for a successful hatch. Variations of more than 1 °F (1.8 °C) from the optimum temperature of 99.5 °F (37.5 °C) will reduce hatch rates

Humidity is also important because the rate at which eggs lose water by evaporation depends on the ambient relative humidity.

Relative humidity should be increased to around 70% in the last three days of incubation to keep the membrane around the hatching chick from drying out after the chick cracks the shell. Lower humidity is usual in the first 18 days to ensure adequate evaporation.

The position of the eggs in the incubator can also influence hatch rates. For best results, eggs should be placed with the pointed ends down and turned regularly (at least three times per day) until one to three days before hatching.

Adequate ventilation is necessary to provide the embryo with oxygen. Older eggs require increased ventilation

Types of incubators

Incubators are the exact copy of hen. At the end of 18th century scientist observed the hen, what the broody hen doing with egg? This process put into the incubator. In 1870 first incubator is observed in America.

Three main types of incubators are: 1.Still air/ small incubator 2.Mammoth/ cabinet incubator 3.Walk-in incubator

Still air/ small incubator

It is simple type of box in which no fan is provided, mostly used in villages in domestic level.

In this incubator we maintain temperature by thermostat

For air we make some small holes. To maintain humidity we use water trays

in the incubator. Turning of eggs is done by hands

(manually).

Mammoth / cabinet incubator Mammoth means large in size also

called as force draft in which air is forced by the help of fan. We draft the air which is uniformly distributed.

In mammoth incubator we provide fan to circulate the air; in this air is distributed equally; it is also called as cabinet incubator.

Temperature remains constant on every egg. It holds up to 1 lac eggs, for the control of temperature we provide heater and thermostat.

For maintenance of humidity water pipes are used. We provide fogging modifier which spray fog type air. Hygro meter is used to measure humidity.

Walk-in incubator

It is large in size that a man can walk in it. The capacity of walk-in incubator is 1 lac to 4-5 lac eggs. In which we can quickly maintain the temperature.

Maintenance of correct temperature in modern incubator is not a problem. Temperature is set automatically

For the ventilation fan has been provided

Level of oxygen should be 21% at the embryo level.

Level of carbon dioxide should not be more than 0.2-0.3%.

Always take relative humidity In case of setter humidity should be

lower 50-65% RH but in case of Hatcher when you transfer eggs humidity level is increased 75-85% RH.

Humidity should be higher in Hatcher:

To make egg shell soft. Out coming chick easily coming out

from egg.

Normally turning is held automatically at 45°. Almost 6-8 turning is sufficient after every 3 hours.

Broader end should be upward. In Hatcher embryo is fully

developed. So, no need of turning.

Seasonal hatching

The effect of season is due to the temperature of incoming air and the relative humidity

Humidity is a key factor during winter

Artificially humidified air is inferior to naturally humidify air because it is inconsistent, inadequate and cools the air

During summer , the problem occur when machine must use moisture for cooling and the embryo must lose the moisture in the limitation of a 21 days incubation cycle

Hatcheries are installing steam humidification so that the cooling quality of the air is improved without actually cooling the room

Critical management points during winter Emphasis should be given on the

setter operation, the room should be warm and humid

The setter should be in the cooling not the heating mode

Critical management points during summer Emphasis should be on the Hatcher

operation, it should cool with minimal spray because if moisture enters egg mass both hatch and chick quality are affected adversely

To make spray as effective as possible, nozzle maintenance and pressure are critical

Relative humidity requirements of the embryo and the machine must be properly balanced