SymptomsProbable
CauseCorrective
MeasuresClear Eggs with no embryonic development (infertiles) Males undernourishedFollow a recommended feeding program to provide adequate nutrition. Replace underweight males with vigorous ones Too few malesIncrease the number of males in the flock. Seasonal decline in fertilityUse young cockerels more resistant to environmental stress. Competition among breeding malesDo not use too many males. Rear all males together. Place temporary partitions within large pens. Diseased flockConduct an approved disease control program. Frozen combs and wattlesProvide comfortable housing. Properly select and maintain drinking fountains. Old malesReplace with younger males. Selected mating in pensArtificially inseminate infertile hens. Replace males in the pen/house. Male sterilityReplace males in the pen/house. Crowded breedersProvide 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 environmentGather eggs frequently (at least once daily). Eggs stored too long or incorrectlyStore eggs at 50-60 degrees F. and 60% relative humidity. Incubate eggs within 7 days of lay.  SymptomsProbable
CauseCorrective
MeasuresBlood ringsImproper storageFollow recommended egg storage and gathering recommendations. Improper incubation temperaturesCheck thermometer accuracy and incubator functions. Follow recommended temperature settings. Improper breeder nutritionFeed breeders a diet with balanced nutrient levels. Improper fumigationFollow fumigation recommendations.  SymptomsProbable
CauseCorrective
MeasuresMany dead embryos at early stagesImproper incubation temperatures (usually too high)Follow recommended incubation temperatures. Improper egg turningTurn at least 3 times daily. Inherited low hatchabilityAvoid cross breeding. May need to secure different breeding stock. Improper ventilationIncrease ventilation rate in incubator and/or room, but avoid drafts. Add oxygen at high altitudes. Pullorum disease or other salmonellosesUse eggs from disease-free sources. Have NPIP representatives blood-test the breeder flock. Improper nutrition of breedersProvide a well-balanced nutritional diet to breeders.  SymptomsProbable
CauseCorrective
MeasuresPipped eggs, but died without hatchingInsufficient moistureIncrease humidity (wet-bulb temperature) during the hatching period. Improper ventilationIncrease ventilation rate in incubator and/or room, but avoid drafts. Improper setting of eggs causing malpositioned embryosSet eggs with small end down. Turn eggs properly but avoid turning within 3 days of hatching.  SymptomsProbable
CauseCorrective
MeasuresEarly hatching (may have bloody navels)High incubation temperaturesFollow recommended incubation temperatures. Check equipment for proper function. Guard against electrical surges or high incubator room temperatures. Improper egg storageStore eggs at 50-60 degrees F. and 60% R.H. Turn at least 3 times daily.  SymptomsProbable
CauseCorrective
MeasuresLate hatching or not hatching uniformlyLow incubation temperaturesFollow recommended incubation temperatures. Warm and cool spots in incubator due to faulty designContact incubator company or obtain a different incubator design. Old or improperly stored eggsGather eggs frequently, cool immediately and store eggs properly. Do not store longer than 7 days.  SymptomsProbable
CauseCorrective
MeasuresSticky embryos (embryos may be smeared with egg contents)High average incubation humidityFollow recommended incubation humidity. Check size of air cell as an indicator for adjusting humidity condition. Low incubation temperatureFollow recommended temperature settings. Lethal genesAvoid cross breeding. May need to secure different breeding stock. Inadequate ventilationIncrease ventilation rate in incubator and/or room, but avoid drafts. Improper fumigation of eggsFumigate eggs by following the procedure carefully.  SymptomsProbable
CauseCorrective
MeasuresEmbryos sticking or adhering to shellLow incubation humidity (especially during hatching)Increase incubation humidity by increasing water evaporation. Embryos dried too much. Excessive ventilation rateReduce ventilation rate but maintain minimum air exchange to prevent suffocation of embryos.  SymptomsProbable
CauseCorrective
MeasuresCrippled and malformed chicksImproper incubation temperatures (usually too high)Follow recommended incubation temperatures. Low incubation humidityIncrease incubation humidity by increasing water evaporation. Embryos dried too much. Improper egg setting position or turning during incubationSet eggs with small ends down. Turn eggs at least 3 times daily. Do not turn eggs within 3 days of hatching. HeredityProper culling and breeding practices will reduce problems. Slick hatching traysUse trays with wire floors or place crinoline on hatching surface. Improper nutrition of breedersProvide a well-balanced nutritional diet to breeders.  SymptomsProbable
CauseCorrective
MeasuresAbnormal, weak, or small chicksHigh incubation or hatching temperaturesFollow recommended incubation temperatures. Small eggs hatch small chicksSet only standard or large sized eggs. Insufficient incubation humidityMaintain recommended humidity for species of bird incubated. Improper ventilation in hatcher unitIncrease ventilation rate, but avoid drafts. Diseased or poorly conditioned breeder flockUse eggs from disease-free sources only. Have NPIP representatives blood-test the breeder flock. Improper nutrition of breedersProvide a well-balanced nutritional diet to breeders (especially vitamin levels). Excessive fumigation in hatcherFumigate using proper procedures.  SymptomsProbable
CauseCorrective
MeasuresChicks with labored breathingExcessive use of fumigantFollow recommended fumigation procedures. Respiratory diseasesCheck disease status of breeder flock. Conduct a thorough cleanup and disinfection of incubator and hatching facilities.  SymptomsProbable
CauseCorrective
MeasuresLarge, soft-bodied mushy chicks; dead on trays; bad odorLow average incubation temperature. poor ventilationFollow recommended incubation temperatures. Increase ventilation rate in incubator and/or room, but avoid drafts. Navel infection (Omphalitis)Clean and disinfect incubator and hatching units between settings of eggs. Maintain dry hatching trays. Properly store and fumigate eggs.  SymptomsProbable
CauseCorrective
MeasuresRough or unhealed navelsImproper incubation temperaturesFollow recommended incubation temperatures. High hatching humidityMaintain proper humidity. Navel infection (Omphalitis)Clean and disinfect incubator and hatching units between settings of eggs. Maintain dry hatching trays. Properly store and fumigate eggs.  SymptomsProbable
CauseCorrective
MeasuresShort down on chicksHigh incubation temperaturesFollow recommended incubation temperatures. Low incubation humidityFollow suggestions to correct insufficient humidity. Excessive ventilationReduce vent openings to restrict but maintain adequate air exchange. Holding chicks in hatcher too long after hatchingRemove all chicks as soon as fluffy but within 24 hours after hatching.  SymptomsProbable
CauseCorrective
MeasuresExcessive yellow coloring of downImproper and excessive fumigation in hatcher unitFollow recommended fumigation procedures.