Hatchability fertile eggs (%)
100
Influence of parent flock age and storage duration on hatchability
The longer the eggs are stored, the longer the incubation time and the lower the hatchability. At least, this is the case if the air temperature in the incubator is not adapted, as eggs stored for a longer period produce less heat. The duration of storage also affects chick weight because the eggs hatch later, and this has an impact on chick quality. So adapt and set the incubation conditions and timing in alignment with the storage duration.
prime (35-50 weeks)
old (> 50 weeks)
50
Storage duration
young (< 35 weeks)
0
0
7 14 Egg storage duration (days)
21
d
Eggs from older flocks maintain their hatch potential for less time during storage than eggs from young hens. The fertilisation rate is also lower.
hatchability (%)
7 6
ec
pr ot
80
Hatchability (%)
90
70 60
ht
albumen height (mm)
5
50
2
4 6 8 Egg storage duration (days)
10
12
40
py
0
rig
Albumen height / pH
100 pH
8
4
te
Changes in the egg during storage 10 9
co
A long storage period has a negative effect on hatchability, the albumen pH and the albumen height. But eggs stored for a short period (1-2 days) have better hatchability than eggs that are set immediately. Especially in eggs from young flocks where egg quality is still high. Degradation of the albumen in fresh eggs is necessary for good gas exchange during incubation. Exposure to ammonia gas can facilitate albumen degradation and, in this case, improve hatchability of short stored eggs from young parents.
Storage duration and optimal storage conditions Storage duration
Storage temperature
Relative humidity
1-3 days
20-23°C
68-73°F
65%
4-7 days
15-18°C
59-64°F
65%
7-10 days
12-15°C
54-59°F
75%
12°C
54°F
75%
Longer than 10 days
The impact of storage Storage impacts on hatching eggs in the following ways: • Each day longer than 7 days in storage, converts to 1 hour extra of incubation time. Eggs stored for a longer period (> 7 days) and fresh eggs must therefore be set at the hatchery at different times. • After 5 days of storage, the hatchability of broiler chicks declines by 0.5 to 1% for each extra day of storage. • When eggs are stored for more than 12 days, the chick quality will be lower at hatch. The effect of hatching egg storage duration on broiler growth can be as much as 200 grams at the age of slaughter. Influence of parent stock Egg size increases as the age of the parent flock advances, while eggshell strength declines. The poorer eggshell quality affects the internal egg quality during storage and incubation. On the other hand, this thinner eggshell could facilitate higher gas exchange. Heavier eggs take longer to incubate in this case (1 hour extra per 5 grams). There is generally a positive correlation between egg production and the hatching result. Lower hatchability is particularly likely if the egg production rate decreases faster than usual.
The storage duration determines the storage temperature. The longer the eggs have to be stored, the cooler the storage temperature. The higher RH during storage is also important as it prevents the eggs from drying out. Most hatcheries have just one storage room. As most of the eggs are stored for between 4 and 7 days, its temperature is set to 16-18°C.
86
Ha tc he ry S i gnal s
