Hatcher management programs
Cobb-Vantress has developed the hatcher management programs as a reference for the ideal time, temperature, ventilation, and...
Cobb-Vantress has developed the hatcher management programs as a reference for the ideal time, temperature, ventilation, and humidity conditions for a proper incubation process.
THE HATCH WINDOW
The hatch window is the time frame spanning from the ﬁrst chick to the last chick hatching.
If the chicks are hatching too early, they can become susceptible to problems such as: dehydration, which can lead to increased 7- and 14-day mortality and poor broiler performance.
Chicks hatching too late can cause:
- poor quality chicks,
- increased pipped eggs, and
- live embryo unhatched eggs.
[caption id="attachment_140100" align="aligncenter" width="616"] Photo 1. Just right[/caption]
[caption id="attachment_140101" align="aligncenter" width="617"] Photo 2. Early hatch[/caption]
It is important to note that you cannot hatch all the chicks at the same time, and it is normal to see a hatch window of 24 to 30 hours from ﬁrst to last chick. Hatch time among eggs varies but is largely dependent on the rate of embryo development where:
- higher incubation temperatures increase metabolism and promote increased embryonic development and
- lower temperatures reduce metabolism and delay embryonic development.
For optimal hatch and chick quality, it is critical to maintain a uniform temperature and humidity across the hatcher.
[caption id="attachment_140103" align="aligncenter" width="587"] Table 1. Hatch window assessment[/caption]
[caption id="attachment_140104" align="aligncenter" width="582"] Graph 1. Ideal percent hatched and ideal hatch spread[/caption]
In addition to chick temperature, the eggshells in the hatcher basket can be used to indicate if adjustments are needed to the time and temperature of chicks in the hatcher.
When chicks have been in the hatcher too long, the eggshells can become soiled with green meconium (the ﬁrst chick droppings)
Clean eggshells can indicate proper hold time in the hatcher but check chicks to ensure they are dry. Completely clean [register] eggshells can also indicate the incubation time is too short.
Check several hatcher baskets for the cleanliness of the shells:
- If all eggshells are clean, the incubation time is correct.
- If all eggshells are very soiled, the chicks have been held for too long.
- If the level of eggshell soilage varies considerably among several baskets in the same hatcher, there may be a temperature or ventilation issue in the hatcher.
CHECKING CLOACAL TEMPERATURES
As chicks begin to emerge from the shell, the temperature in the hatcher must be gradually lowered to prevent overheating and dehydration of the newly hatched chicks.
Begin proﬁling the temperature lower when approximately 25% of the chicks have hatched. Do not go below 97.0 °F until at least 75% of the chicks have hatched.
[caption id="attachment_140105" align="aligncenter" width="618"] Graph 2. Hatcher temperature proﬁle for high and low air ﬂow[/caption]
In even the best scenario, the hatch window in commercial operations will be at least 24 hours, and though the goal of every hatchery manager is to remove the chicks from the hatcher as soon as they are ready, it is not feasible. Instead, chicks are normally held in the hatchers for several hours until all hatchlings are ready.
During this holding period, the temperature in the machine must be lowered consistently to prevent overheating the chicks.
Cloacal temperature can be used as an indication of overheating with normal temperature range being 40.0 to 40.6°C (104.0 to 105.0 °F).
- At a minimum check cloacal temperatures at the 12 hour hatch window and every 3 to 4 hours afterward.
- The last check should be right before pull from the hatcher.
- Record temperatures at the 12 hour hatch window and the last check just before pull.
[caption id="attachment_140106" align="aligncenter" width="636"] Photo 3. Temperature eﬀects on the navel[/caption]
VENTILATION AND HUMIDITY
It is impossible to correct moisture loss in the hatcher if it is not properly achieved in the incubator, because humidity must be maintained in the hatcher after transfer.
Humidity is necessary during the hatching process so that the shell membranes remain soft and pliable allowing the chick to hatch easily. At extremes:
>>a low relative humidity (RH) in the hatcher can delay the hatch window and, in some studies, has been correlated with higher 7-day mortalities,
>>while a very high RH may lead to an increased incidence of exposed viscera.
Adequate humidity will also prevent the yolk sac from drying too quickly, preventing strings or wicks from the navel.
[caption id="attachment_140118" align="aligncenter" width="631"] Table 2. Ventilation and humidity[/caption]
We recommend: Biosecurity in the hatchery: The basics by Cobb-Vantress