ANSC 605 Hatching Management

Selecting and Storing Hatching Eggs

• Select eggs that are normal size, shape, color, and shell texture

• Do not scrub or soak eggs

• Only store dry eggs

• Store clean, fertile eggs at 50-60 farenheit and 70-75% humidity

• Slant or turn fertile eggs daily

• Do not store more than 10-14 days

• Before “setting”, allow them to warm to room temp

Egg “Sweating”

• Occurs when cool eggs are exposed to a sudden increase in temperature or relative humidity

• Moisture will promote the growth of microorganisms on the shell surface

• If egg then cools and contents extract, organisms can be drawn into shell through pores

Monitoring During Incubation

Majority that fail to hatch die:

• within first few days of starting incubation 

• Just before hatch

Assess eggs with weighing, candling, ± heart rate monitor 

Identify non-viable eggs and cull them from incubator

• No embryo development 

• Cracked, leaking, or moldy

Candling

• Bright light that comes through an opening smaller than diameter of egg

Hand-held and tabletop models

• Homemade options are possible

Advantages of Candling

Easier to assess

• in a dark room

• White shelled/ lightly pigmented eggs

Candle eggs twice during incubation

• 7-10 days

• 3-4 days before hatch

Handle eggs gently and work quickly

First Candling 

• Incubation day 7-10 

• Loss of incubated eggs at first candling should be <1/3 of total expected 

• Most common causes of loss at this time are improper egg handling and storage 

Findings:

• Living, normal embryos 

• Blood rings 

• detached or ruptured air cell 

• “Clears” 

Living Normal Embryo

• Clearly defined blood vessels with no hemorrhagic/ruptured areas evident

• Some body movement when stimulated by candlelight

• Generally healthy appearance

Blood Rings

• Thin ring of blood outlined on the inner surface of the shell

• Embryo died early in incubation

• May also see a vague, patchy area

Clears

• Eggs that show no development

• True Infertile: No fertilization occured

• Fertile, no development: Lethal genetics, improper storage

• Positive development: Embryo dies very early, but division of cells on surface of the yolk continues for multiple days

Second Candling

• Loss of incubated eggs at second candling should be <2/3 of total expected

• At 3-4 days before hatch, when stop turning

Normal Embryo

• Distinct demarcation of air cell

Dead Embryo

• Murky contents that move freely within egg

• Jagged/ruptured air cell

Heart Rate Monitor

• Uses infrared tech to detect and display embryonic heart rate

Average expected ~300 bpm

• Will slow if egg is cooled

• Heart rate of males tends to be slightly lower than females, but not consistent enough to use to sex embryos

During Incubation 

Balance temp and humidity 

• ~55% humidity at start of incubation and increases during hatch 

With proper humidity, egg will lose 12-14% of its weight during incubation 

• low humidity gives sticky chicks that can’t exit shell 

Preparing for Hatch

• Hatch in incubator or move to dedicated hatcher

• If moving, do so 3-4 days before

• If in an incubator, suggest using a liner (easy to clean, and smooth surface)

• Optimal hatching temp is 0.5-1 °F cooler than for incubation, with humidity 6-10%

Pipping

• Act of breaking out of the shell (3 days prior to hatch)

Internal Pipping

• Embryo breaks into air cell and begins to breathe

External Pipping

• Egg tooth: Sharp, temporary keratin cap on tip of upper beak

• Pipping muscle: Back of neck, spasms to create pipping motion

Hatching Issues 

Early Hatch

• Small eggs, breed/strain differences

• Temperature too high or humidity too low 

Late Hatch 

• Large eggs 

• Eggs stored too long before incubation 

• Temp too low or humidity too high 

• Old or inbred breeder flock 

Draggy Hatch 

• Normal hatches take 12-24 hours between first and last hatching, but can “drag on”

If Chick Fails to Pip

Malpositioning of Chick

• High humidity, failing to keep blunt/wide end of egg higher

Help Outs

• Not recommended to assist chick in hatching

• Could be a hereditary issue that will perpetuate more birds that need assistance in hatching

• Almost always have crooked feet or a twisted neck

• If you must only intervene if the bird has at least started to break through the shell

Crooked Toes 

• Can be associated with overcrowding and smooth flooring in brooder

• Also nutritional deficiencies, genetics, and incubation issues

• May predispose to pododermatitis if untreated but most do great

• Treat as early as possible with “chick shoes” for a few days

Splayed and Spraddled Legs 

• Can be associated with smooth flooring + weak chicks 

• If it is not corrected, birds will have a very hard time walking/navigating the environment 

• Treat as early as possible with hobbles and training to walk properly 

Beak Deformities

• Can lead to difficulties eating and drinking

• Likely hereditary

Scissor beak

• Upper and lower beak grow in opposite directions

Can also be upper beak is too long

Beak Deformities Treatment 

Trimming overgrown keratin can be done

• Dremel tool, nail file, nail clippers 

• Be careful of the underlying tissues 

Other Hatchling Issues

Starve-out

• Chicks do not eat within 2-3 days of hatch the birds become too weak to actively seek food

• Long transit time, poorly accessible feeders

Coccidiosis

Smothering

• Chicks pile on top of eachother

Pasting/pasty butt

Manure balls on toes

Culling a Sickly Animal

Normal death rate: 5-10% during brooding

• Most die in the first week after hatch

• Cause for concern if multiple chicks die at once or persist and exhibit clinical signs signs