Hatchery Practice"recognizing the normal hatching position"

A number of embryos fail to hatch because they end up in so called malposition .Not all the malpositions are leathel but they should be recognized by the person examining the egg and record in case their frequency changes as a result of inappropriate management practice

HATCHERY PRACTICE:::MALFORMATION OF HATCHED CHICK

HEAD

MALFORMATION :EXPOSED BRAIN

Missing eyes,exposed brain,beak and face abnormalities.

possible cause:  high early incubation temperature or nutritional deficiencies.

ASSESSING FERTILITY: .BREAKING OUT PARTIALLY INCUBATED EGGS:.....STEP 2

The fertility test undertaken on partially incubated eggs requires the destruction of some hatching eggs,but is easier and requires considerably less practice then examining fertility in un incubated eggs ,once again a 100 eggs sample per flock is the minimum requirement ,although it is usually more practical to use one or more full setter try.Eggs should have been incubated for 3 to 5 days proir to examination each egg should be opened very carefully from the top of the air cell so as to avoid any disruption to the egg contants,then the blastoderm or infertile disc will be on th upper surface of the yolk and very easy to see.do not spend too much time trying to identify signs of membrane development if it is not obvious it has not happened

ASSESSING FERTILITY:EXAMINATION OF FRESH UNINCUBATED EGGS (BREAKING OUT)..BLASTODERM :STEP 0NE

BREAKING OUT FRESH UN-INCUBATED EGGS

after fertilization,the eggs spends about a day travelling down the oviduct.during this time the number of cells in the blastoderm increases to about 60000.the characteristic organization of these cells just under the yolk sac membrane make it possible,with practice,to distinguish between an infertile blastodisc and a fertile blastoderm when breaking out fresh un incubated eggs.

EMBRYO LOSS DURING INCUBATION

Normal pattern of embryo losses during incubation

On x-axis there are days of incubation.

On y-axis there is probability of lossing embryo.