A017 GB Issue 04
12
Weigh the eggs on the day they are set in the incubator, take the average weight and plot this
on a graph (see example below). The ideal weight loss line can be plotted by joining the point
representing initial average weight with the ideal hatch weight (13-16% less depending on
species) with the x-axis representing the incubation period (in days).
By measuring actual average weights every few days the actual weight loss can be plotted and
compared to the ideal weight loss line and corrections can be made. For example if the actual
weight loss was greater than ideal (see graph below) then the air has been too dry and humidity
levels need to be increased to compensate.
Typical ideal weight losses for species groups:
Poultry
13%
Parrots
16%
Waterfowl
14%
Egg weight loss chart
54
56
58
60
62
64
66
68
2
5
8
11
14
17
20
Incubation period (days)
Average egg weight
(grams)
Ideal weight (grams)
Measured weight
(grams)
8.3
Of the methods given above the most reliable is egg weight method and is recommended – particularly
where poor hatch rates are experienced or if eggs of high value are being incubated.
8.4
SETTING THE RELATIVE HUMIDITY LEVEL
Press the - and + buttons simultaneously to unlock the Main Menu.
Press the + button to scroll to the RH% option.
Press OK to select the RH% screen and adjust as necessary using the + and – buttons.
Press OK to return to the Main Menu and then scroll down to SAVE. Press OK to save the changes.
If the humidity level in the incubator is lower than the Set Humidity Level the pump will start to turn
(sometimes brief pulses) and gradually draw water from the tank and pump it to the evaporation card in
the incubator. This may take a few hours to pump through and stabilise after which the pump will run
intermittently as the humidity level is controlled.
The pump will not run if the incubator is significantly below the set temperature. This is to prevent the
system adding too much water when the top has been opened for inspecting eggs etc.
8.5
In all cases the humidity for hatching needs to be high. Because of the short duration involved
water/weight loss will not be significantly affected. High humidity is necessary to prevent membranes
drying and hardening before the hatch fully emerges. Humidity will naturally increase as the first eggs
begin to hatch and internal membranes begin to dry. This is in addition to the water added by the pump.
