Symptoms

Probable Cause

Corrective Measures

Clear Eggs with no embryonic development (infertiles)

Males undernourished

Follow a recommended feeding program to provide adequate nutrition. Replace underweight males with vigorous ones

Too few males

Increase the number of males in the flock.

Seasonal decline in fertility

Use young cockerels more resistant to environmental stress.

Competition among breeding males

Do not use too many males. Rear all males together. Place temporary partitions within large pens.

Diseased flock

Conduct an approved disease control program.

Frozen combs and wattles

Provide comfortable housing. Properly select and maintain drinking fountains.

Old males

Replace with younger males.

Selected mating in pens

Artificially inseminate infertile hens. Replace males in the pen/house.

Male sterility

Replace males in the pen/house.

Crowded breeders

Provide recommended floor space, at least 3 ft²/bird.

Improper artificial insemination techniques or use of old/over-diluted semen.

Follow recommendations of primary breeder company.

Eggs damaged by environment

Gather eggs frequently (at least once daily).

Eggs stored too long or incorrectly

Store eggs at 50-60 degrees F. and 60% relative humidity. Incubate eggs within 7 days of lay.

Symptoms

Probable Cause

Corrective Measures

Blood rings

Improper storage

Follow recommended egg storage and gathering recommendations.

Improper incubation temperatures

Check thermometer accuracy and incubator functions. Follow recommended temperature settings.

Improper breeder nutrition

Feed breeders a diet with balanced nutrient levels.

Improper fumigation

Follow fumigation recommendations.

Symptoms

Probable Cause

Corrective Measures

Many dead embryos at early stages

Improper incubation temperatures (usually too high)

Follow recommended incubation temperatures.

Improper egg turning

Turn at least 3 times daily.

Inherited low hatchability

Avoid cross breeding. May need to secure different breeding stock.

Improper ventilation

Increase ventilation rate in incubator and/or room, but avoid drafts. Add oxygen at high altitudes.

Pullorum disease or other salmonelloses

Use eggs from disease-free sources. Have NPIP representatives blood-test the breeder flock.

Improper nutrition of breeders

Provide a well-balanced nutritional diet to breeders.

Symptoms

Probable Cause

Corrective Measures

Pipped eggs, but died without hatching

Insufficient moisture

Increase humidity (wet-bulb temperature) during the hatching period.

Improper ventilation

Increase ventilation rate in incubator and/or room, but avoid drafts.

Improper setting of eggs causing malpositioned embryos

Set eggs with small end down. Turn eggs properly but avoid turning within 3 days of hatching.

Symptoms

Probable Cause

Corrective Measures

Early hatching (may have bloody navels)

High incubation temperatures

Follow recommended incubation temperatures. Check equipment for proper function. Guard against electrical surges or high incubator room temperatures.

Improper egg storage

Store eggs at 50-60 degrees F. and 60% R.H. Turn at least 3 times daily.

Symptoms

Probable Cause

Corrective Measures

Late hatching or not hatching uniformly

Low incubation temperatures

Follow recommended incubation temperatures.

Warm and cool spots in incubator due to faulty design

Contact incubator company or obtain a different incubator design.

Old or improperly stored eggs

Gather eggs frequently, cool immediately and store eggs properly. Do not store longer than 7 days.

Symptoms

Probable Cause

Corrective Measures

Sticky embryos (embryos may be smeared with egg contents)

High average incubation humidity

Follow recommended incubation humidity. Check size of air cell as an indicator for adjusting humidity condition.

Low incubation temperature

Follow recommended temperature settings.

Lethal genes

Avoid cross breeding. May need to secure different breeding stock.

Inadequate ventilation

Increase ventilation rate in incubator and/or room, but avoid drafts.

Improper fumigation of eggs

Fumigate eggs by following the procedure carefully.

Symptoms

Probable Cause

Corrective Measures

Embryos sticking or adhering to shell

Low incubation humidity (especially during hatching)

Increase incubation humidity by increasing water evaporation. Embryos dried too much.

Excessive ventilation rate