Count and assess unhatched eggs
py
rig
ht
pr ot
ec
te
d
The unhatched eggs among the empty shells are collected here from twenty hatching baskets in order to analyse the cause of death.
You should also count the unhatched eggs. Perform a breakout analysis of random samples (at least six baskets), to see the stage or day when the embryo died. Carefully examine the distribution of these cases, and try to determine whether most embryos died in the second week (in the setter) or during hatching. Try to think if there is a way to reduce the percentage of unhatched eggs. One possibility is that that too many infertile eggs or eggs with early embryonic mortality were not detected during candling and transfer. If this is the case, check the candling process. If you want to trace the causes of deviations with more certainty, give the setter trays an identification mark before transfer (e.g., upper, middle, and lower trolley positions). Collect the eggs rejected at candling for a breakout analysis and do the same with the hatcher baskets. Then you count these eggs, assess the quality, and collect the unhatched eggs for breakout analysis. Do this for each hatcher basket. In this way, you have a good picture of the process, from start to finish. Do not add any other eggs during transfer: the data must be pure.
co
Aspergillus causes increased embryo mortality around day 15-16. This fungal infection is clearly visible if you open the unhatched egg at the blunt end.
Perfectly formed chicks but still dead in the hatcher basket These mortalities were possibly caused by external factors. Maybe one of the personnel handled the hatcher basket too roughly, the hatcher basket was damaged, or the hatch window was very wide. If the chicks are fully formed but have a soft body with a bad odour, there is a possibility that the cause is an E. coli or Aspergillus infection. Floor eggs that were still placed in the setter could also be behind this problem. A chick that did not break out of the egg at all but died around day 18.
142
Ha tc he ry S i gnal s
