Temperature settings
Adjust incubator temperature to suit eggshell temperature
The most important aspect of the incubating process is the correct incubator temperature setpoint. The heat produced by the embryo must be removed, especially in the second stage of incubation. Incubating is in fact more about cooling properly rather than heating. This especially applies to broiler embryos and slightly less to laying hen embryos. In some incubators, the average eggshell temperature after day 10 may be allowed to increase slightly to prevent too low temperatures in some of the hatching eggs, which will then hatch too late. After pipping, the eggshell temperature may increase further and reach up to 38.9°C (102°F) at hatching. The average dry chick temperature will then be 39-40°C (103-104°F). If the temperature is too low, the chicks often hatch a little later, but they are not likely to suffer any negative consequences. If the temperature is too high, the chicks will hatch, but their condition will be affected, so their subsequent performance is poorer. When you enter the temperature settings, follow the advice of the incubator manufacturer and breeding company. You can adjust the settings for the next batch based on the quality of the day-old chicks produced.
Correct average incubator temperature: 15% of eggs too cold
Machine temperature slightly higher: 5% of eggs incubated too hot
97°F 36.1°C
eggs too hot
98°F 99°F 100°F 101°F 36.7°C 37.2°C 37.8°C 38.3°C Eggshell temperature on day 18
102°F 38.9°C
103°F 39.4°C
Insight into variation A hatchery manager must properly understand the variations in eggshell temperature before making any adjustments to the incubator temperature! It is always about balancing the number of chicks that can be saved by making adjustments and potential losses due to mortality or poorer quality. Incubation is much more complex than simply entering the right settings in the machine display. It is primarily about steering and responding to embryonic development and knowing and satisfying its needs, as well insight into the effect of air flows in the incubator. Variations in the stages of development in a batch and differing incubation conditions also cause variations in day-old chick quality.
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Signals of different embryo temperatures
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Increasing the average eggshell temperature by 0.3°C to 38.1°C (0.6°F to 100.6°F) in the plateau phase ensures that more eggs are incubated within the optimal range if the EST is less uniform. This will, however, compromise the quality of some of the embryos who now incubate at a too high temperature. However, in view of the results as a whole, it may be a wise decision because eggs that are incubated too cold will not hatch in time. This leads to even higher losses. It is better to eliminate cold and hot spots altogether and ensure a uniform eggshell temperature in every part of the incubator.
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eggs too cold
te
Proportion of eggs in incubator (%)
Higher machine temperature
Assessment
Result
98.0-99.5°F (36.7-37.5°C)
Too cold
Slow hatchability (too late), poor chick quality
99.5-100.5°F (37.5-38.1°C)
Optimal
Good hatchability, good chick quality
100.5-102.5°F (38.1-39.2°C)
Too hot
102.5-104.0°F (39.2-40.0°C)
Too hot
co
py
Embryo temp. (day 15/18)
Good hatchability, lower chick quality Poor hatchability, poor chick quality
There is a direct relationship between the embryo temperature on day 15-18 and the hatching results.
Effects of increasing incubation temperature on the results of broilers Egg shell temperature (°F/°C) Week 1
Week 2
Week 3
Yolkfree body mass
Heart weight (g)
Length (cm)
Hatchability (%)
Body weight at 7 days
Image fits
98/36.7
100/37.8
102/38.9
33.8
0.28
18.3
77.8
148
multi-stage
100/37.8
100/37.8
100/37.8
37.9
0.36
19.4
84.7
155
single-stage
The eggshell temperatures also have a longer-term effect on broilers. A stable eggshell temperature is vital. If the temperature is initially too low, and then becomes too high, all the characteristics above will be negatively affected. In a multi-stage incubator, the parameters are geared to the average egg. The temperature of eggs that have only been in the incubator for a week will be too low and the temperature of eggs that are already in week 3 of the incubation will be too high. Maintaining a stable eggshell temperature is much easier in a single-stage incubator. 32
Ha tc he ry S i gnal s
