Incubation is a very delicate process and the final results depend on a lot of different aspects. 

Below is a summary of some of the aspects that can create problems in the field, with their possible causes. This overview is by far not complete and will not provide answers to all problems and situations that can occur, but is intended as a guideline. 

The overview is based on the work of H.R. Wilson, 1993.

 

Troubleshoohting Guide for Hatchability Problems

1. Sign: Eggs candler clear; broken out eggs show small white – dot germinal disc ; no blood . Infertile

Causes:

1. Immature males.
2. Males with abnormal sperm; females with abnormal egg ( germinal disc ) . This occurs most often in very young or very old breeders .
3. Too few males, resulting in infrequent mating; too many males, resulting in fighting or interference. Ratios of 1:12 to 1:15 for light breeds and 1:10 to 1:12 for heavy breeds are suggested.
4. Extreme weather conditions.
5. Old breeders. Spiking with young males may help if the problem is with the males.
6. Breeder flock disease. This is often indicated by rough, misshaped, discoloration of the egg shell or thin – shelled eggs.
7. Excess body weight, especially in broiler breeder males
8. Nutritional deficiencies or excesses; too severe feed restriction, especially on the males.
9. Feet and leg problems , especially in males of heavy breeds.
10. Certain drugs, pesticides, chemicals, toxins or mycotoxins.
11. Parasites, such as mites.
12. Inadequate floor space, especially for the males in rearing.
13. Decreased mating frequency, or no mating, is commonly seen in many of the conditions listed above; this may often to be direct cause of infertility.
14. Inadequate lighting (intensity or day length).
15. Improper insemination procedures (if artificial insemination is used ) .

2. Sign: Eggs candler clear; broken out eggs show enlarged germinal disc; no blood. Fertile. Some are termed „blastoderm without embryo „

Causes:

1. Eggs stored too long. Preferably they should not be stored for longer than 7 days.
2. Eggs held under poor conditions, temperature too low but especially too high. Fluctuating temperatures. Temperature should be between 15 and 18^o
3. Fumigation too severe or done between 12 and 96 h of incubation. Incorrectly spraying or foaming eggs with disinfectant.
4. Eggs damaged during handling and transport by jarring.
5. Eggshell sealed – respiration inhibited.
6. Incorrect temperature in early incubation.
7. Very young or very old breeders .
8. Heredity , inbreeding ,chromosome abnormalities , or parthenogenesis .
9. Breeder flock diseases.
10. Egg wash temparature too high.
11. Egg – borne infections (e.g. Salmonella)
12. Drugs, toxins, pesticides, etc.
13. Infrequent or incomplete egg collection, eggs overnight in the nests.

3. Sign : Eggs candle clear ; broken out eggs show blood ring or small embryo that died before 3 days of incubation ; no dark eye visible .

Causes :

1. Eggs stored too long or under improper temperature.
2. Fumigation improper – too severe or done between 12 and 96 h of incubation.
3. Incorrect temperature in early incubation.
4. Eggs damaged during transport by jarring, etc.
5. Breeder flock diseases.
6. Old or very young breeders.
7. Embryological development accidents.
8. Inbreeding, chromosome abnormalities.
9. Severe nutritional deficiencies, eg biotin, vitamin A, Copper (Cu), vitamin E, Boron (B), or pantothenic acid.
10. Frequently associated with a high incidence of infertility.
11. Drugs, toxins, or pesticides.
12. Contamination

4. Sign : Dead embyos ; 3 to 6 days of incabation ; yolk sac circulatory system present , embryo on left side , no egg tooth .

               Causes:

3. See Causes 3.a – l.
4. Improper turning - < 1 /h or >6/ h; improper turning angle.
5. Vitamin deficiencies – vitamin E, riboflavin, biotin, pantothenic acid, or linoleic acid .

5. Sign: Dead embyos; 7 to 17 days of incubation; embryo has egg tooth, toenails , feather follicles ( 8 days ), feathers ( 11 days ).

     Causes :

1. Improper incubation temperature, turning, ventilation. Low humidity increases abnormalities of aortic arches ( 13 days ) .
2. Contamination :
3. Nutritional deficiencies – riboflavin, vitamin B₁₂, biotin, niacin, pyrodoxine, pantothetic acid, phosphorus, boron, or linoleic acid .
4. Lethal genes ( > 30 have been described )

6. Sign : Dead embryos - > 18 days of incubation

Causes

1. Improper incubator temperature, turning, ventilation, moisture loss .
2. Improper hatcher temperature, ventilation .
3. Contamination, especially from molds Aspergillus , etc).
4. Fumigation too severe or too prolonged .
5. Eggs transferred too late.
6. Broken shell – pre –set, during incubation, or at transfer.
7. Nutritional deficiencies – vitamin D, vitamin A, folic acid, pantothenic acid, riboflavin, vitamin E, selenium, vitamin K, biotin, vitamin B₁₂, calcium, phosphorus, manganese, or linoleic acid .
8. Embryonic malposition; embryo fails to move into proper hatching position (see #21 ) .
9. Embryological development accident. Failure to change to lung respiration, and / or to retract the intestines and yolk sac . These and other changes are critical at this time.
10. Heredity – lethal genes, chromosome abnormalities.
11. Hatcher opened too much during pipping and hatching.
12. Poor shell quality.
13. Breeder diseases

7. Sign: Not pipped. Full –term embryo, large yolk sac; yolk sac may not be fully enclosed by abdominal wall, may have residual albumen .

Causes:

1. Inadequate turning , resulting in decreased embryonic membrane development and nutrient adsorption .
2. Humidity too high during incubation or after transfer (not enough moiture loss, too small air cell)
3. Incubation temperature too low.
4. Hatcher temperature too high.
5. Eggs chilled (e.g. , at transfer) causing delayed hatch .
6. Nutritional deficiencies.
8. Embryological development accident.
9. Breeder diseases.
10. Inadequate ventialation causing temperature fluctuations, especially in hatcher but also in setter.
11. Prolonged egg storage.

8. Sign : Pipped . Full – term embryo dead in shell .

Causes :

1. Low temperature for a prolonged period.
2. High temperature during hatching.
3. Nutritional deficiencies.
4. Breeder diseases.
5. Poor ventilation.
6. Inadequate turning during first 12 days .
7. Injury or crack during transfer.
8. Prolonged egg storage.

9. Sign : Shell partially pipped , embryo alive or dead .

 Causes :

8. See Causes 8.a-i
9. Excessive fumigation during hatching.
10. Egg set small end up.

10. Sign : Chick hatch early ; tendency to be thin and noisy .

Causes :

1. Small eggs.
2. Differences among breeds.
3. Incubator temperature too high.
4. Lack of cooling capacity in setter and/or hatcher

11. Sign: Chicks hatch late .

Causes:

1. Large eggs .
2. Old or very young breeders .
3. Long egg storage.
4. Incubator temperature too low .
5. Weak embryos.

12. Sign : Slow , protracted (dragging) hatch .

Causes :

1. Mix in the incubator of eggs stored for long and short periods.
2. Mix of eggs from young and old breeders.
3. Mix of large and small eggs.
4. Improper egg handling.
5. Hot or cold spots in incubator or hatcher, due to too much spraying, non-uniform air velocity or too much ventilation
6. Incubator or hatcher temperature too high or too low.
7. Room ventilation system improper: high positive pressure or low negative pressure. Such pressures may alter incubator or hatcher ventilation .

13. Sign : Trays not uniform in hatch or chick quality.

Causes :

1. Mix of large or small eggs.
2. Mix of eggs from young and old breeders.
3. Mix of eggs from different strains or breeds.
4. Some eggs stored much longer.
5. Lack of uniform ventilation in setter or hatcher.
6. Lack of uniform egg shell temperature in setter or hatcher.
7. Disease or other stress in one or more breeder flocks.
8. Variation in egg storage procedures among flocks.

14. Sign : Sticky chicks; chicks smeared with albumen.

Causes :

1. Low incubation temparature, especially at start of incubation.
2. Insufficient moisture loss.
3. Improper turning. This results in reduced embryonic membrane growth reduced nutritient absorption.
4. Old eggs.
5. Very large eggs.

15. Sign : Chicks stuck in shell, dry; chicks with fragments stuck to down feathers.

Causes :

1. Humidity too low during hatching, membranes dry out during hatching process.
2. Improper egg turning.
3. Cracked eggs or poor shell quality.

16. Sign : Premature hatching bloody navels

Cause :

1. Incubator and / or hatcher temperature too high .

17. Sign : Small chicks.

Causes :

1. Small eggs.
2. High incubation temperatur .
3. High altitude. Hatcheries at high altitudes ( > 1000 m ) may need to adjust for humidity, carbon dioxide and oxygen . Atmospheric pressure at high altitudes reduces oxygen availability.
4. Thin , porous shells.

18. Sign : Unhealed navel; dry, rough down feathers .

Causes:

1. High incubator temperature or wide fluctuations in temperature.
2. Low temperature in hatcher.
3. Humidity too high in hatcher or not lowered when hatching complete.
4. Inadequate breeder nutrition.

19. Sign: Unhealed navel; wet, odorous, mushy, large, soft – bodied , and lethargic chick .

Causes :

1. Omphalitis ( navel infection). Contamination from dirty trays, unsanitary machines or hatchery, dirty eggs, inadequate egg sanitation or fumigation
2. Low incubator temperature.
3. High incubator or hatcher humidity .
4. Inadequate ventilation .

20. Sign : Weak chicks .

Causes :

1. High hatcher temparature .
2. Poor hatcher ventilation .
3. Excessive fumigation .
4. Contamination .

21. Sign : Chicks malpositioned . Normal position after 19 days of incubation : embryo’s long axis same as long axis of egg ; head in large end ; head to the right and under right wing ; beak toward air cell ; feet toward head .

Causes :

1. Egg set small end up or in fixed horizontal position.
2. Inadequate or improper turning.
3. High or low incubator temperature.
4. Old bredeers.
5. Round – shaped eggs or very large eggs.
6. Nutritional deficiencies , especially vitamin A and vitamin B_{12 .}
7. Eggs handled or stored improperly.
8. Retarded development .

Embryos < 18 days old may be in position different from that for hatching but one normal for their age ( for example , the head – between – thighs position ) . The feet – over – head position is hard to distinguish and may be normal . The beak – over – wing position is the result of too high temperature. Some malpositions are lethal; others are not.

22. Sign : Malformations .

Causes :

1. Improper egg storage.
3. Nutritional deficiencies, e.g. biotin, riboflavin, zinc or manganese.
4. Inadequate turning.
5. Improper egg orientation, e.g. small end up .
6. High or low incubator temperature.
7. Breeder diseases.
8. Inadequate ventilation or shells with low porosity or permeability.

23. Sign : Crooked toes; spraddled legs.

Causes :

1. High or low incubation temparature.
2. Inadequate nutrition.
3. Smooth bottom hatching trays.

24. Sign : Short down, wiry down.

Causes :

1. Nutritional deficiencies, especially riboflavin.
2. Mycotoxins and other toxic inhibitory substances, resulting in nutritional deficiencies.
3. High incubation temperature during days 1 to 14.

25. Sign : Eyes closed , down stuck to eyes.

Causes :

1. Temperature too high in hetcher.
2. Humidity too low in hatcher.
3. Chicks remain in hatcher too long after hatching.
4. Excessive ventilation in hatcher .

26. Sign : Exploders.

Causes :

1. Dirty eggs from nests. Dirty nests.
2. Floor eggs.
3. Eggs improperly washed; eggs whiped or cleaned with contaminated cloth or buffer.
4. Dust from breeder house, cooler, transport, etc.
5. Water condensation on eggs ( sweating ).
6. Water sprayed , fogged , or splashed on eggs; eggs dipped in contaminated solutions.
7. Leaking or dripping spraying nozzles in setters or hatchers
8. Contamination from earlier exploders, leakers, or broken eggs.
9. Contamination from handling eggs with dirty hands on equipment.
10. Contaminated setter flats, air filters, water (humidity) system .

27. Sign : Dwarf embryos: runts in growth chicks.

Causes :

1. Egg contamination.
2. Hatchery contamination, especially during hatching.
3. Breeder diseases.
4. Heredity .
5. Nutritional deficiencies.
6. Thyroid abnormalities.

28. Sign : Crossed beak , twisted beak .

Cause :

2. Malposition head over wing,
3. High egg shell temperature at the end of incubation

29. Sign : Missing eye (s) , other eyes abnormalities .

Causes :

6. High incubator temperature during days 1 to 6.
7. High egg shell temperature at the end of incubation
8. Malposition head over wing

30. Exposed brain .

Causes :

3. High incubator temperature during days 1 to 3.

31. Sign : Red hocks in hatched chicks or unhatched pips.

Causes :

1. Prolonged pushing on shell during pipping and hatching .
2. Vitamin deficiencies.
3. Thick shells, as in pullet flocks .
4. Low moisture loss
5. High or low incubator temperature .

32. Sign : Small air cell, broad pip area, membrane incompletely cut, red hocks, unabsorbed albumen, yolk incompletely retracted, egg weight loss < 10 % .

Causes :

1. High incubator humidity.
2. Insufficient moisture loss
3. Very thick shells , as in pullet flocks .
4. Low incubator temperature .

33. Sign : Micromelia (shorted long bones, parrot beak, bent bones); chondrodystrophy (similar to micromelia ) .

Causes :

1. Heredity, lethal genes.
2. Nutritional deficiencies (biotin or manganese).

34. Sign : Short beak, missing beak, face abnoramalities .

Causes :

5. Incubator temperature too high during days 1 to 5.
6. Heradity, lethal genes.
7. Developmental accidents.
8. Nutritional deficiencies (niacin).

35. Sign : Ectopic (exposed) viscera.

Causes :

1. Incubator temperature too high.
2. Heredity, lethal genes.

36. Sign : Red skin

Causes :

1. Incubator or hatcher temperature too high.
2. Bleeding in chorioallantois – rough handling at transfer.
3. Nutritional deficiencies (vitamin K or E).
4. Embryos that died at days 11 to 15 and appear small and dark or dark red are usually caused by molds or bacterial contamination.