User's Manual

MJ192 GB Issue 02
8
7.6
Recommended temperatures: Typical incubation period:
Hens 37.4 – 37.6°C 99.3 – 99.6°F 21 days
Pheasant 37.6 – 37.8°C 99.6 - 100°F 23-27 days
Quail 37.6 – 37.8°C 99.6 - 100°F 16-23 days
Ducks 37.4 – 37.6°C 99.3 – 99.6°F 28 days
Geese 37.4 – 37.6°C 99.3 – 99.6°F 28-32 days
7.7 Developing embryos are fairly tolerant of short term temperature drops and the user need not be concerned about
cooling that occurs when inspecting eggs. Temperatures above ideal can quickly have a serious detrimental
effect on hatch rates and must be avoided.
7.8 Ova-Easy Advance incubators have a built-in temperature alarm which warns of high or low temperatures. See
section 5 for details.
8 Humidity and Ventilation
Short term variations in humidity are not important. The average humidity over the incubation period needs to be near
optimum to achieve the ideal weight loss. High humidity for the day or two of hatching is also important. Beware
chronic, excessive humidity.
Two main factors affect incubation humidity: water evaporation within the cabinet (from eggs as well as from
additional water) and levels of ventilation. The water content of the air being drawn through the incubator will also have
an effect.
There are two methods available to bird breeders to achieve correct humidity levels in the Ova-Easy Advance:
8.1 Monitor humidity levels and adjust to match published guidelines for different species.
Generally accepted incubation RH levels for species groups:
During incubation Poultry 40-50% RH
Waterfowl 45-55% RH
Hatching All species 60% RH or more
For more specific information on particular species’ requirements check the relevant literature.
8.2 Monitor egg weight loss which varies as a direct result of humidity and correct against published weight loss
figures for the species.
Eggs lose moisture through their shells and the rate of evaporation depends on the humidity levels around the
eggs and the shell porosity. During incubation eggs need to lose a fixed amount of water which corresponds to a
loss in weight of around 13-16% depending on species. By weighing eggs periodically during incubation it is
possible to monitor and, if necessary, correct humidity levels to achieve the correct weight loss.
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.