and living embryos

The display on the candling unit shows which eggs are infertile (blue), and which have mortalities (red). The remaining eggs contain a living embryo.

Infertile eggs, bangers, late mortalities, and living embryos

You can establish which eggs contain dead embryos up to day 7 with lamp candling. After that time, the embryo will have grown and light is no longer able to shine through as well. This depends on the candling machine settings. With the heartbeat method, you can determine which eggs contain dead or live embryos at the time of transfer. Combining different candling techniques gives you an accurate impression of various groups of eggs that you want to exclude from transfer. You can then handle them differently.

Infertile or an early mortality?

How can you recognise truly infertile eggs when candling on day 10 or 18? How can you detect unhatched eggs (embryos that died after day 18 or live chicks that failed to hatch)? It is easy to recognise a truly infertile egg on day 18. The yolk and albumen have aged; the egg has been stored at a higher temperature in the incubator for 18 days. The yolk is still dark yellow but it has a thinner membrane, which causes the yolk to form a flat disc or break when opening the egg. The albumen has become watery, and the thick (chalaziferous) albumen has disappeared. You can still recognise a small white dot on the yolk.

If the embryo died before the blood ring stage, there will be clearly recognisable colour changes in the yolk. Formation of sub-embryonic fluid causes the water content of the albumen to pass through the embryo and into the yolk, this changes its colour to light-yellow. The yolk always breaks after 18 days of copyright protected incubation: in this case, the yolk membrane has become very fragile. Sometimes you can still see extra-embryonic membranes in the broken yolk: a sign that the embryo was there but not really viable.

Method

This is how it looks

How does it work? Strong light does not penetrate through the embryo, and it produces a certain image. A dead embryo produces a different illuminated image. This method detects the embryo’s blood circulation and the oxygen content of the blood. A dead embryo has no circulation of oxygen-rich blood. The embryo’s heat production is detected. A dead embryo does not produce any heat.

Light Heartbeat Infrared

A candling unit that works with heat sensors. This can be installed after a unit that uses light. Candling with light identifies infertile eggs and early embryo mortalities. These eggs can still be used in the processing industry (e.g., shampoo). A heat detection system identifies dead embryos (they do not produce any heat). These eggs are destroyed.

CALCULATION EXAMPLE Candling capacity

How long does the candling take? With the heartbeat detection method, it takes 6 seconds per tray to determine which hatching eggs have live or dead embryos. Transporting them in and out takes 3 seconds. So, 6 + 3 = 9 seconds in total for a tray. 3,600 seconds: 9 seconds = 400 trays per hour. To double-check the candling equipment, it is a good 400 trays * 150 eggs per tray = 60,000 eggs idea to open random samples of the eggs to check per hour. for false positives. A bar is used here to separate the selected eggs temporarily. If a spot check reveals too much deviation, contact the supplier, who can then calibrate and adjust the candling unit. You can candle up to 60,000 eggs an hour with a heartbeat detector, the same as candling with light. A suction cup attaches to each hatching egg. A light beam then shines through the egg. This detects whether the embryo has active blood circulation. Each setter tray with eggs is illuminated for 5-6 seconds. copyright protected

A completely clear egg when illuminated: infertile. Here, light candling shows a clear blood ring: mortality around day 3. Some irregularities in the egg: mortality between days 5 and 10 (black eye). A dark egg: well developed embryo.