Diamond Incubators
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Frequently Asked Questions


1. Basic Requirements of Hatchery Room

The most critical factor for setting up a Hatchery is Hatchery Room itself. The following points should be considered for setting up a Hatchery Room:

1.       It should be airy and well ventilated. In winter and at cold places it is not essential to have an airy room. Room temperatures from 70o F – 80o F should be maintained. Similarly sunspots on the Machine should be avoided during summer Season by using curtains on windows.
2.       Place your incubator near a gas heater where carbon dioxide concentration in the air might be high and kill your embryo.
3.       Keep visitors out of the hatchery room as much as possible to avoid the possibility of introducing disease.

2. Eggs Picking & Storing

Eggs should be picked up daily and stored in egg flats with the small ends down. The Flats should be tilted twice a day. On very hot days the hatching egg may be kept in the kitchen refrigerator in a plastic bag. Sprinkle the eggs with a little water and seal the bag. This will preserve humidity. Make sure that the eggs are placed far away from the freezer section so that the eggs do not freeze. Let your eggs stay at room temperature for a least twelve hours before setting in your Incubator (20-degree F). Eggs should be stored in a separate place than the hatchery room.

3. Setting of Eggs

Eggs should be set after careful handling. In ‘DAYAL’ incubators it normally takes 3 minutes for setting eggs in an incubation tray. No packing of any sort is needed. Eggs of any size can be accommodated properly in the special tray provided. While placing eggs in the incubation trays the pointed/small end of the eggs should be down wards. Place trays in the incubators, pushing them back until these the rear of ranks. The turning of the eggs is completely automatic and does not require any handling. All the incubation eggs should be put in the incubators according to serial numbers marked on the eggs at their appropriate place.

4. Washing Of Hatching Eggs

The washing of hatching eggs is not recommended although many producers think that visual cleanliness will increase their chances of incubation success. It is more important to stress providing good nesting facilities and frequent egg collection to reduce egg contamination. Cleaning of eggs will then become unnecessary.

The reason that washing is harmful is that washing aide’s bacteria to penetrate the egg shell through the small egg shell pores. The egg has many natural defenses to prevent the bacteria from moving through the shell. Washing removes the egg shell's natural defenses against bacterial entry, and water provides an environment that allows the organisms to literally swim through the shell pores. When this occurs, the egg is overwhelmed by more bacteria than it can destroy and egg contamination results. Several washing aids and antibiotics have been tested to destroy the bacteria but have not consistently improved egg hatchability.

If dirty eggs must be used for hatching, it is recommended that they be incubated in an incubator separate from the clean eggs. This will prevent contamination of clean eggs and chicken if the dirty eggs explode and during hatching.

5. Hatching Egg Storage Period

Eggs saved for hatching are very perishable and their viability is greatly affected by the quality of storage conditions. If properly stored, the number of hatching failures can be kept to a minimum. It is recommended that most eggs be stored no longer than 1 week. Storing eggs longer will produce a greater incidence of hatching failures.

The maximum storage period for chickens is about 3 weeks. Some turkey eggs will survive for 4 weeks, but quail will have difficulty developing from eggs stored longer than 2 weeks.

Hatching eggs should be collected soon after lay and maintained at 50-65o F. The eggs must not warm to above 65o F. unless they are being prepared for immediate incubation. Relative humidity in the storage facility should be maintained at 70 percent and daily egg turning or repositioning is recommended to prevent the yolk from sticking to the inside surface of the shell.

6. Incubation And Hatching Of Chicken Eggs In The Incubating Compartment

Most operators find as average temperature of 99.5 degree best for incubating chicken eggs. However, 99¾ degree is preferred when the incubator is only partly filled especially at the beginning and end of the hatching season.
Schedule of Incubation of different kinds of eggs                                     


Incubator Period

Hatching Period


º F





1 to 18 days

from 18 to 21 days


82 degree

88 degree


1 to 25 days

from 25 to 28 days


80 degree

88 degree


1 to 25 days

from 25 to 28 days


84 degree

88 degree


1 to 21 days

from 21 to 24 days


80 degree

86 degree


1 to 14 days

from 14 to 17 days


80 degree

86 degree


1 to 27 days

from 27 to 30 days


80 degree

88 degree

7. Fumigation And Sanitation Of Hatching Eggs

Sanitize eggs and equipment before storage or use by fumigating. Under-fumigation does not kill the bacteria, but over- fumigation can kill the chick embryo in the egg. Use recommended amounts of chemicals at the right time for the length of time specified.

A room or cabinet large enough to hold the eggs is required. It must be relatively air tight and equipped with a small fan to circulate the gas. Calculate the inside volume of the structure by multiplying the inside length by the width by the height.

8. Sanitation Of Hatching Eggs

All incubation factors like temperature and humidity can be operating just right but poor hatchability can result because of poor sanitary practices. Poor sanitation causes not only poor hatch but subsequent early death loss during brooding. It can also cause a lingering morbidity problem that sometimes affects the birds during the grow-out period. Losses during the brooding and grow-out period caused by poor hatchery sanitation can cause more monetary loss than the loss from poor hatchability.

The most important tools available for use in cleaning and disinfecting an incubator and hatcher are water, detergent, and elbow grease. Some people mistakenly think disinfecting agents are the answer to their problems. They think disinfectants can replace poor cleaning, but this simply is not true.

Remember this: It is almost impossible to disinfect a dirty environment. Why is this statement true? Because all disinfectants lose much of their effectiveness as soon as they come in contact with organic matter; the dirtier the surface being sanitized, the less effective the disinfectant being applied.

Some disinfectants are more effective in the presence of organic matter than others. Cresol, cresylic acid, and coal tar disinfectants are the most effective disinfectants in the presence of organic matter. Since they are corrosive and emit noxious and toxic gases, they are not normally used in incubators, but in cleaning and disinfecting bird houses and pens.

The most commonly used disinfectants in the hatchery are quaternary ammonia compounds (quats), multiple phenolics, and iodophors (iodine compounds).

Quaternary ammonia may be the most commonly used disinfectant for equipment like incubators and hatching trays because quats are relatively non-irritating, non-corrosive, of low toxicity, and reasonably effective in the presence of organic matter. Since the incubator and its components should be cleaned free of organic matter before applying a disinfectant, quats are a good choice.

Many hatchery men use multiple phenolics. They have a wide germicidal range, low toxicity and corrosiveness, reasonably good effectiveness in the presence of organic matter, and good residual effect. The disadvantage is that multiple phenolics can cause a burning effect on the skin of anyone handling them in a strong solution or during a relatively long period of time. If using multiple phenolics at concentrations greater than the solution strength suggested on the label, wear rubber gloves for protection.

Iodophores have wide germicidal activity, good effectiveness in the presence of organic matter, and cost less than quats or multiple phenolics. The disadvantages are that it stains, is corrosive when in acid solution, and has only a slight residual activity.

A thorough cleaning job using plenty of elbow grease results in a 95 to 99 percent microbial removal. In such case, and when done often enough, little or no disinfectant is needed (assuming you are setting clean eggs). If, on the other hand, you are using a quick "hit or miss" system and a long time passes between thorough cleanup jobs, you are most likely falling short in disinfecting your machines. It is best to use a disinfectant following cleanup and maybe between cleanup jobs.

9. Incubation Duration Periods

The duration required for a chick to develop and hatch from an egg varies greatly depending on bird species. In general, the incubation periods are 21 days for chickens, 23 days for bobwhite quail, 28 days for turkeys and most ducks, 17 days for Coturnix (pharaoh) quail and about 33 days for geese.

The length of incubation will vary depending on egg collection and storage conditions and incubation conditions. Length of the incubation period can be altered drastically if recommended conditions are not maintained.

10. Incubation Temperature Requirements

The incubation temperature requirements for most hatching eggs are surprisingly uniform. The eggs of almost all domestic bird species (and many wild species) can be incubated at the same incubation temperature. Therefore, eggs of several different bird species can be incubated at the same time within the same incubator.

The incubation temperature of naturally (nest) incubated eggs is controlled by the hen. The recommended temperature within an artificial incubator depends upon the type of incubator being used. If the incubator used has a fan for air circulation, the temperature must be adjusted to 99-100o F.

An incubator without an air circulation system requires a higher temperature. The temperature in this "still-air" incubator is measured using a thermometer with the bulb positioned at the same level as the top of the incubating eggs. The recommended temperature in this type incubator is 102o F.

The reason for different temperatures is that circulating air warms all points around the egg shell while still air temperatures are warmer at the top of the egg than at the bottom. Therefore, increasing the temperature at the top of the egg will compensate for the egg's cooler parts. The same average egg temperature of 100o F can be maintained (for the entire egg) if the higher temperature of 102o F exists at the egg's uppermost point.

Do not allow temperatures to exceed these recommendations, even for only a short period of time. Although it is not recommended, slightly lower temperatures will not kill the chick embryos, but can increase incubation times and produce weakened chicken. Temperatures only a degree or two above the recommended temperatures can kill chicken within 15-30 minutes, depending on how high the temperature is and the stage of development of the chick embryo.

11. Important Incubation Factors

When incubating any bird egg it is important to control the same factors of temperature, humidity, ventilation, and egg turning. The chart shown below lists the major incubation factors and the values of each that produces the best incubation conditions for the species of birds shown.

Poor results are most commonly produced with improper control of temperature and/or humidity. Improper control means that the temperature or humidity is too high or too low for a sufficient length of time that it interferes with the normal growth and development of the embryo. Poor results also occur from improper ventilation, egg turning and sanitation of the machines or eggs.

Obtain the best hatch by keeping the temperature at 100º F. throughout the entire incubation period when using a forced-air incubator. Minor fluctuations (less than ½ degree) above or below 100 degrees are tolerated, but do not let the temperatures vary more than a total of 1 degree. Prolonged periods of high or low temperatures will alter hatching success. High temperatures are especially serious.

Humidity is carefully controlled to prevent unnecessary loss of egg moisture. The relative humidity in the incubator between setting and 3 days prior to hatching should remain at 58-60 percent or 84-86º F., wet-bulb. When hatching, the humidity is increased to 65 percent relative humidity or more.

Frequently there is confusion as to how the measurement of humidity is expressed. Most persons in the incubator industry refer to the level of humidity in terms of degrees F., (wet-bulb) rather than percent relative humidity. The two terms are interconvertible and actual humidity depends upon the temperature (F.) as measured with a dry-bulb thermometer. Conversion between the two humidity measurements can be made using a psychrometric table.

Ventilation is very important during the incubation process. While the embryo is developing, oxygen enters the egg through the shell and carbon dioxide escapes in the same manner. As the chicken hatch, they require an increased supply of fresh oxygen. As embryos grow, the air vent openings are gradually opened to satisfy increased embryonic oxygen demand. Care must be taken to maintain humidity during the hatching period. Unobstructed ventilation holes, both above and below the eggs, are essential for proper air exchange.

Eggs must be turned at least 4-6 times daily during the incubation period. Do not turn eggs during the last 3 days before hatching. The embryos are moving into hatching position and need no turning. Keep the incubator closed during hatching to maintain proper temperature and humidity. The air vents should be almost fully open during the latter stages of hatching.

The eggs are initially set in the incubator with the large end up or horizontally with the large end slightly elevated. This enables the embryo to remain oriented in a proper position for hatching. Never set eggs with the small end upward.

The following table lists incubation requirements for various species of fowl.


Incub. Period



Do not turn

3 days ²

Open vent





18th day


18th day





25th day


25th day





25th day


25th day

Muscovy Duck




31st day


30th day





25th day


25th day

Guinea Fowl




25th day


24th day





21st day


20th day





25th day


25th day

Bobwhite Quail




20th day


20th day

Coturnix Quail




15th day


14th day





20th day


20th day





22nd day


21st day





15th day


14th day

¹ Measured at degrees F. in a forced-air incubator.

² Measured as degrees F. using a wet-bulb thermometer. Use chart to convert to relative humidity.

12. Pipped Eggs That Do Not Hatch

If chick embryos develop to the pipping stage, or at first shell cracking at hatching, they are normally healthy enough to hatch unless some incubator adjustment prevents it from happening. The problem is usually caused by either

1) poor ventilation

2) improper humidity.

The air exchange requirement within an incubator is greatest during the last day of incubation. The chick embryo's oxygen requirement continually increases during development and especially when breathing using the respiratory system just before hatching. The vent openings are frequently restricted at this time in an attempt to boost incubator humidity. Instead of helping the chick hatch, the chick is suffocated from lack of ventilation. Never decrease ventilation openings at hatching in an attempt to increase humidity. Increase humidity by other methods. If any vent adjustments are made, they should be opened more.

Another reason for mortality during hatching is improper humidity adjustment. The deaths can be produced from too much humidity during the entire incubation period or from too little humidity during the hatching period.

The desired egg weight loss during incubation caused by water evaporation is about 12 percent. If humidity during incubation is kept too high, adequate water evaporation from the egg is prevented. The chick can drown in the water remaining in the shell at hatching. A dried coating around the chick's nostrils and beak indicates that drowning was likely. Attention to maintaining proper incubation humidity during incubation will reduce the potential for this problem at hatching time.

If the humidity is allowed to decrease after the chick pips the shell, the membranes within the shell can dry-out and stick to the chick. This prevents the chick from turning inside the shell and stops the hatching process. The chick eventually dies. If the membranes around the shell opening appear dried and shrunken, the cause is probably low humidity during hatching. This condition can occur quickly (within 1 or 2 minutes) when the incubator is opened to remove or assist other chicken that are hatching. When hatching begins and proper incubator conditions are attained, the incubator should never be opened until after all chicken are hatched and ready for placement in the brooder.

13. Chick Removal From Hatchery

The time period that is normally recommended between hatching and removal of chicken from the hatching unit or incubator is about 1 to 24 hours.

The earliest elapsed time before removal is usually about 1 hour. The ideal chick must be able to walk well and has dried fluffy down. If the chick is still wet, it should stay in the Hatcher even if all other chicken are ready for removal. A wet chick becomes quickly chilled and often dies soon after removal.

If all eggs do not hatch within 24 hours after the first hatchling emerges, open the hatching unit and remove all dry chicken. Leave wet chicken until they are dry and strong. It is best to remove chicken at 18 to 24 hours intervals after the first chick hatches. If chicken are still hatching when the Hatcher is opened, it is important to quickly remove dry chicken and close the Hatcher before the humidity drops too low.

The primary reason for not allowing the chicken to stay in the Hatcher for longer periods is excess dehydration of the chicken. The chicken have enough food reserves to provide their bodies with nourishment for 3 days. They do not have additional moisture reserves and can become dehydrated if left in the Hatcher too long. A dehydrated chick is identified by looking at the scaly portion of the legs (shanks). If the shanks are smooth and rounded, the chick is normal and does not immediately need water. If the shanks are angular and show sharp angles on the front and backs, they are dehydrated and in a stage of stress. Be sure that plenty of cool, fresh drinking water is available in the brooding area.

14. Trouble Shooting Failures With Egg Incubation

When incubation of eggs fails, indications are often available that a well trained professional uses for diagnosing the causes for failure. The information listed below includes the more common symptoms for incubation failures, the causes for each symptom, and the recommended corrective measures

Symptoms of incubation/breeder management problems include:

1) Clear eggs with no visible embryonic development.

2) Blood rings in incubated eggs.

3) Many dead embryos at an early stage.

4) chicken fully formed, but dead without pipping.

5) Pipped eggs, but died without hatching.

6) Early hatching (may have bloody navels).

7) Late hatching or not hatching uniformly.

8) Sticky embryos.

9) Embryos sticking or adhering to shell.

10) Crippled and malformed chicken.

11) Abnormal, weak, or small chicken.

12) chicken with labored breathing.

13) Large, soft-bodied mushy chicken; dead on trays; bad odor.

14) Rough or unhealed navels on chicken

15) Gasping chicken.

16) Delayed hatch; eggs do not starting to pip until 21st day or later

17) Draggy hatch, some chicken early

18) Short down on chicken.

19) Excessive yellow down color.

Symptom 1 :- Clear Eggs with no embryonic development (infertile).

Problem Cause Corrective Measures

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.
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.

Symptom  2:- Blood rings in incubated Eggs.

Problem Cause Corrective Measures
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.

Symptom  3:- Many dead embryos at early stages.

Problem Cause Corrective Measures
Improper incubation temperatures (usually too high) Check accuracy of thermometer. Follow recommended incubation temperatures.
Improper egg turning Turn eggs at regular intervals.
Inherited low hatchability Avoid cross breeding. May need to secure different breeding stock.
Improper ventilation/ Lack of ventilation Increase ventilation rate in incubator and/or room, but avoid drafts. /Provide adequate ventilation of the incubator and Check for openings of incubator rota  vents.
Pull rum disease or other salmonellae's Use eggs from disease-free sources. Have your representative’s blood-test the breeder flock.
Improper nutrition of breeders Provide a well-balanced nutritional diet to breeders.

Symptom  4:- chicken fully formed, but dead without pepping.   

Problem Cause Corrective Measures
Low Average Humidity in Incubator, too low or too high humidity at transfer time in the Hatcher Maintain proper humidity levels through out incubation & hatching cycle.

Symptom  5:- Pipped eggs, but died without hatching.

Problem Cause Corrective Measures
Low average humidity. Maintain proper humidity levels through out incubation & hatching cycle.
Inadequate ventilation or excessive fumigation during course of hatch. Provide adequate ventilated room & proper openings of rota vents of the machine.
Low average. Maintain proper temperature throughout incubating & hatching cycle.

Symptom  6:- Early hatching (may have bloody navels).

Problem Cause Corrective Measures
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.

Symptom  7:-  Late hatching or not hatching uniformly.

Problem Cause Corrective Measures
Low incubation temperatures. Follow recommended incubation temperatures.
Old or improperly stored eggs. Gather eggs frequently, cool immediately and store eggs properly. Do not store longer than 7 days.

Symptom  8:-  Sticky embryos (embryos may be smeared with egg contents).

Problem Cause Corrective Measures
High average incubation humidity. Follow recommended incubation humidity. Maintain proper humidity levels through out incubation & hatching cycle.
Low incubation temperature. Follow recommended temperature settings.
Lethal genes. Avoid cross breeding. May need to secure different breeding stock.
Inadequate ventilation excessive fumigation  during course of hatch. Provide adequate ventilated room & proper openings of rota vents of machine. Follow recommended instructions regarding fumigation.

Symptom  9:-  Embryos sticking or adhering to shell.

Problem Cause Corrective Measures
Low incubation humidity (especially during hatching). Increase incubation humidity by increasing water evaporation. Embryos dried too much.
Excessive ventilation rate. Reduce ventilation rate but maintain minimum air exchange to prevent suffocation of embryos.

Symptom  10:-  Crippled and malformed chicken.

Problem Cause Corrective Measures
Improper incubation temperatures, usually too high. (Missing eye). Follow recommended incubation temperatures.
Improper temperature. This can also be caused by setting too few eggs per tray permitting too much freedom of movement to chicken.  (Crooked Toes) Maintain proper temperature levels through out incubating and hatching cycle. Do not set too few eggs per tray.
Heredity (Cross Beak) Proper culling and breeding practices will reduce problems.
Hatching trays which are too smooth. Almost never encountered in Dayal Incubators (Spraddle Legs) Use crinoline cloth on hatching trays.
Improper nutrition of breeders. (Wry Neck) Provide a well-balanced nutritional diet to breeders.

Symptom  11:-  Abnormal, weak, or small chicken.

Problem Cause Corrective Measures
High incubation or hatching temperatures. Follow recommended incubation temperatures.
Small eggs hatch small chicken. Set only standard or large sized eggs.
Insufficient incubation humidity. Maintain recommended humidity for species of bird incubated.
Improper ventilation in Hatcher unit. Increase ventilation rate, but avoid drafts.
Diseased or poorly conditioned breeder flock. Use eggs from disease-free sources only. Have NPIP representative’s blood-test the breeder flock.
Improper nutrition of breeders. Provide a well-balanced nutritional diet to breeders (especially vitamin levels).
Excessive fumigation in Hatcher. Fumigate using proper procedures.

Symptom  12:-  chicken with labored breathing.

Problem Cause Corrective Measures
Excessive use of fumigant. Follow recommended fumigation procedures.
Respiratory diseases. Check disease status of breeder flock. Conduct a thorough cleanup and disinfection of incubator and hatching facilities.

Symptom  13:-  Large, soft-bodied mushy chicken; dead on trays; bad odor.

Problem Cause Corrective Measures
Low average incubation temperature. Follow recommended incubation temperatures. Increase ventilation rate in incubator and/or room, but avoid drafts.
Poor ventilation. Provide adequate ventilation of incubating room and maintain proper openings of the incubator & Hatcher rota vents.
Navel infection (Omphalitis). Clean and disinfect incubator and hatching units between settings of eggs. Maintain dry hatching trays. Properly store and fumigate eggs.

Symptom  14:-  Rough or unhealed navels.

Problem Cause Corrective Measures
High temperature or wide temperature variation. Maintain proper temperature levels throughout  incubation & hatching cycle.
High hatching humidity. Use less humidity for first 24 to 36 hours after transfer.
Navel infection (Omphalitis). Clean and disinfect incubator and hatching units between settings of eggs. Maintain dry hatching trays. Properly store and fumigate eggs.

Symptom  15:-  Gasping chicken.

Problem Cause Corrective Measures
Excessive fumigation in the Carry out approved disease control practice. See instruction on fumigation during the course of hatching procedure.
Respiratory diseases as Bronchitis or Newcastle Hatcher. carry out approved disease control practice.

Symptom  16:-  Delayed hatch; eggs do not start to pip until 21st day or later.

Problem Cause Corrective Measures
Average temperature too low. Maintain correct temperature throughout incubation & Hatching cycle.
Eggs held to long import gathering holding of eggs. Try not to hold eggs more than 3 days.

Symptom  17:-  Draggy hatch, some chicken early.

Problem Cause Corrective Measures
Improper gathering & holding of eggs. Eggs must be gathered frequently, cooled quickly and held at proper temperatures and humidity before setting.

Symptom  18:-  Short down on chicken.

Problem Cause Corrective Measures
High incubation temperatures. Follow recommended incubation temperatures.
Low incubation humidity. Follow suggestions to correct insufficient humidity.
Excessive ventilation at hatching time. Reduce openings of Hatcher rota vents. Restrict opening of top ventilation. Do not but maintain adequate air exchange.
Holding chicken in Hatcher too long after hatching. Remove all chicken as soon as fluffy but within 24 hours after hatching.

Symptom  19:-  Excessive yellow coloring of down.

Problem Cause Corrective Measures
Improper and excessive fumigation in Hatcher unit. Follow recommended fumigation procedures.


15. Stages In Chick Embryo Development

One of the greatest miracles of nature is the transformation of the egg into the chick. A chick emerges after a brief three weeks of incubation. The complexity of the development cannot be understood without training in embryology.

When the egg is laid, some embryonic development has occurred and usually stops until proper cell environmental conditions are established for incubation to resume. At first, all the cells are alike, but as the embryo develops, cell differences are observed. Some cells may become vital organs; others become a wing or leg.

Soon after incubation begins, a pointed thickened layer of cells becomes visible in the caudal or tail end of the embryo. This pointed area is the primitive streak, and is the longitudinal axis of the embryo. From the primitive streak, the head and backbone of the embryo develop. A precursor of the digestive tract forms; blood islands appear and will develop later into the vascular or blood system; and the eye begins.

On the second day of incubation, the blood islands begin linking and form a vascular system, while the heart is being formed elsewhere. By the 44th hour of incubation, the heart and vascular systems join, and the heart begins beating. Two distinct circulatory systems are established, an embryonic system for the embryo and a vitelline system extending into the egg.

At the end of the third day of incubation, the beak begins developing and limb buds for the wings and legs are seen. Torsion and flexion continue through the fourth day. The chick's entire body turns 90o and lies down with its left side on the yolk. The head and tail come close together so the embryo forms a "C" shape. The mouth, tongue, and nasal pits develop as parts of the digestive and respiratory systems. The heart continues to enlarge even though it has not been enclosed within the body. It is seen beating if the egg is opened carefully. The other internal organs continue to develop. By the end of the fourth day of incubation, the embryo has all organs needed to sustain life after hatching, and most of the embryo's parts can be identified. The chick embryo cannot, however, be distinguished from that of mammals.

The embryo grows and develops rapidly. By the seventh day, digits appear on the wings and feet, the heart is completely enclosed in the thoracic cavity, and the embryo looks more like a bird. After the tenth day of incubation, feathers and feather tracts are visible, and the beak hardens. On the fourteenth day, the claws are forming and the embryo is moving into position for hatching. After twenty days, the chick is in the hatching position, the beak has pierced the air cell, and pulmonary respiration has begun.

After 21 days of incubation, the chick finally begins its escape from the shell. The chick begins by pushing its beak through the air cell. The allantois, which has served as its lungs, begins to dry up as the chick uses its own lungs. The chick continues to push its head outward. The sharp horny structure on the upper beak (egg tooth) and the muscle on the back of the neck help cut the shell. The chick rests, changes position, and keeps cutting until its head falls free of the opened shell. It then kicks free of the bottom portion of the shell. The chick is exhausted and rests while the navel openings heal and it’s down dries. Gradually, it regains strength and walks. The incubation and hatching is complete. The horny cap will fall off the beak within days after the chick hatches.

Chicken Embryo - Day One Chick Embryo - Day Two Chick Embryo - Day Three Chick Embryo - Day Four Chick Embryo - Day Five Chick Embryo - Day Seven
Day1 Day2 Day3 Day4 Day5 Day6 Day7
Chick Embryo - Day 8 Chick Embryo - Day 9 Chick Embryo - Day Ten Chick Embryo - Day Eleven Chick Embryo - Day 12 Chick Embryo - Day 13 Chick Embryo - Day 14
Day8 Day9 Day10 Day11 Day12 Day13 Day14
Chick Embryo - Day 15 Chick Embryo - Day 16 Chick Embryo - Day 17 Chick Embryo - Day 18 Chick Embryo - Day 19 Chick Beginning to Pip Through Shell Chick Hatching From Egg
Day15 Day16 Day17 Day18 Day19 Day20 Day21

 Before Egg Laying:

  • Fertilization

  • Division and growth of living cells

  • Segregation of cells into groups of special function (tissues)

Between Laying and Incubation

  • No growth; stage of inactive embryonic life

During Incubation:


First day

  • 16 hours - first sign of resemblance to a chick embryo

  • 18 hours - appearance of alimentary tract

  • 20 hours - appearance of vertebral column

  • 21 hours - beginning of nervous system

  • 22 hours - beginning of head

  • 24 hours - beginning of eye


Second day

  • 25 hours - beginning of heart

  • 35 hours - beginning of ear

  • 42 hours - heart beats

Third day

  • 60 hours - beginning of nose

  • 62 hours - beginning of legs

  • 64 hours - beginning of wings

  • Fourth day - beginning of tongue

  • Fifth day - formation of reproductive organs and differentiation of sex

  • Sixth day - beginning of beak

Eighth day

  • Beginning of feathers

Tenth day

  • Beginning of hardening of beak

Thirteenth day

  • Appearance of scales and claws

Fourteenth day

  • Embryo gets into position suitable for breaking shell

Sixteenth day

  • Scales, claws and beak becoming firm and horny

Seventeenth day

  • Beak turns toward air cell

Nineteenth day

  • Yolk sac begins to enter body cavity

Twentieth day

  • Yolk sac completely drawn into body cavity; embryo occupies practically all the space within the egg except the air cell.

Twenty-first day

  • Hatching of chick


16. Testing Incubated Eggs For Embryo Development

Sometimes it is necessary to test the incubated eggs for fertility. If large numbers of infertile eggs are incubated, they can be found and discarded, and the extra space used for additional eggs. This test will not injure the young embryos and is reliable for eliminating eggs that will not hatch.

Make a tester or candler by placing a light bulb and fixture inside a cardboard box. Cut a small, round hole in the top or side of the box, and let a narrow beam of light escape from the box. You can see the internal features of the egg by placing it against the hole. A darkened room makes testing easier.

The eggs are normally tested after 4 to 7 days of incubation. Eggs with white shells are easier to test and can be tested earlier than dark shelled eggs. Two classes of eggs can be removed on the basis of this early test, "infertiles" and "dead germs." "Infertile" refers to an unfertilized egg or an egg that started developing but died before growth could be detected. "Dead germs" refers to embryos that died after growing large enough to be seen when candled.

An "infertile" appears as a clear egg except for a slight shadow cast by the yolk. A live embryo is spider-like in appearance, with the embryo representing a spider's body and the large blood vessels spreading out much like a spider's legs. A "dead germ" can be distinguished by the presence of a blood ring around the embryo. This is caused by the movement of blood away from the embryo after death.

If you are not sure whether the embryo is alive, place the egg back in the incubator and retest later. A second test can be made after 14 to 16 days of incubation. If the embryo is living, only one or two small light spaces filled with blood vessels can be seen, and the chick may be observed moving.

17. Contents Of Chicken Egg

The avian egg, in all its complexity, is still a mystery. A highly complex reproductive cell, it is essentially a tiny center of life. Initial development of the embryo takes place in the blastoderm. The albumen surrounds the yolk and protects this potential life. It is an elastic, shock-absorbing semi-solid with a high water content. Together, the yolk and albumen are prepared to sustain life - the life of a growing embryo - for three weeks, in the case of the chicken. This entire mass is surrounded by two membranes and an external covering called the shell. The shell provides for an exchange of gases and a mechanical means of conserving the food and water supply within.

The egg is formed in the mature hen by a reproductive system composed of an ovary and oviduct. Most females have two functional ovaries, but chickens and most other birds have only one ovary and one oviduct. In this oviduct, all parts of the egg, except the yolk, are formed. It is divided into five distinct regions: (1) infundibulum or funnel, (2) magnum, (3) isthmus, (4) uterus or shell gland, and (5) vagina.

The yolk is formed in the follicular sac by the deposition of continuous layers of yolk material. Ninety-nine percent of the yolk material is formed within the 7-9 days before the laying of the egg. When the yolk matures, the follicular sac ruptures or splits along a line with few, of any, blood vessels. If any blood vessels cross the stigma, a small drop of blood may be deposited on the yolk as it is released from the follicle. This causes most blood spots in eggs. After the yolk is released from the follicle, it is kept intact by the vitelline membrane surrounding it. The release of the yolk from the ovary is called "ovulation."

After its release from the follicle, the yolk falls into the hen's abdominal cavity. The infundibulum of the oviduct quickly engulfs the yolk with its thin, funnel-like lips. The yolk quickly enters the magnum section of the oviduct where the dense portion of the albumen is added. The shape of the egg is largely determined in this section.

The magnum of the oviduct is divided from the isthmus by a narrow, translucent ring without glands. The isthmus is smaller in diameter than the magnum. It is here the two shell membranes form. The shell membranes loosely contain the yolk and dense white until the rest of the albumen is added in the uterus.

The shell is added in the uterus or shell gland portion of the oviduct. The shell is composed mainly of calcium carbonate. It takes about 20 hours for the egg shell to form. If the hen lays brown eggs, the brown pigments are added to the shell in the last hours of shell formation.

The chalazae, two cord-like structures which keep the yolk centered in the egg, first appear in the uterus. The chalazae also function as an axis around which the yolk can rotate and keep the germinal disc in hatching eggs uppermost at all times.

In the last portion of the oviduct, the vagina, a thin, protein coating called "bloom" is applied to the shell to keep harmful bacteria or dust from entering the egg shell pores. The egg passes through the oviduct small end first, but is laid large end first. In the vagina, the egg is turned horizontally just before laying. If the hen is disturbed on the nest, the egg may be prematurely layed small end first. "Oviposition" is the act of pushing the egg from the oviduct.

When an egg is laid, it fills the shell. As it cools, the inner portion of the egg contracts and forms an air cell between the two shell membranes. A high quality egg has a tiny air cell, indicating the egg was collected soon after being layed and was stored properly. The air cell is usually located in the large end of the egg where the shell is most porous and air can enter easily.


18. Sanitation: Cleaning And Disinfectants

Diseases and infections have always been a major concern to the poultry industry--especially in the hatchery. Fortunately, microbial contamination can be prevented and controlled using proper management practices and modern health products.

Microorganisms are everywhere! Some are relatively harmless while others are highly pathogenic. Some pose a lethal threat to one species of animal while remaining harmless to another species. Some organisms are easily destroyed while others are very difficult to eliminate. The moral is: Treat all microorganisms as if they are a severe threat to the chick's livelihood.

Understanding the terms used to describe microbial control is important when selecting the appropriate action for eliminating disease causing organisms. Three terms commonly used but often misunderstood are sterilization, disinfection, and sanitation.

  • Sterilization - The destruction of all infective and reproductive forms of all microorganisms (bacteria, fungi, virus, etc.).
  • Disinfection - The destruction of all vegetative forms of microorganisms. Spores are not destroyed.
  • Sanitation - The reduction of pathogenic organism numbers to a level at which they do not pose a disease threat to their host.

Most hatchery personnel have the impression that they are approaching a sterile condition because they use disinfectants when "disinfecting" the facilities. In fact, they may only achieve a sanitized condition at the very best. The most important consideration to remember when striving for a sanitized hatchery is that cleanliness is essential.

Proper cleaning of facilities removes the vast majority of all organisms and must be used before application of disinfectants. This applies to all areas within the hatchery including floors, walls, setters, hatchers, trays, chick processing equipment, air and personnel. The success of a hatchery sanitation program is limited only by its weakest link.

It is extremely important to remove as much organic matter as practicable from surfaces to be disinfected. All debris including down, egg shells, droppings, tissue residues, etc. must be removed from the hatchery. This is followed by thorough cleaning using warm water and appropriate cleaning aides. Care is focused on selecting the proper detergent and thus producing the cleanest hatchery environment possible. Special attention is placed on compensating for variations in hardness, salinity and pH of the cleaning water. A thorough rinsing with abundant quantities of clean sanitized water completes the cleaning process and removes most lingering residues of detergents, organic matter or microbial organisms that can interfere with the effectiveness of a disinfectant.

Only after the facilities have been thoroughly cleaned are the surfaces treated with an appropriate disinfectant solution. Not all disinfectants are suited for every situation. When selecting the right disinfectant, carefully consider:

  1. The type of surface being treated.
  2. The cleanliness of the surface.
  3. The type of organisms being treated.
  4. The durability of the equipment/surface material.
  5. Time limitations on treatment duration.
  6. Residual activity requirements.

If the surface is free of organic matter and residual activity is not required, quaternary ammonium compounds and possibly halogen compounds can be used effectively. However, if surfaces are difficult to clean, residual activity is required or the contaminating organisms are difficult to destroy, then multiple phenolics or coal tar distillates may be needed.

Careful attention must assure that the disinfectant, if used as directed, meets requirements of the user. Be reasonable and don't expect the product to produce unattainable performance. Instead, select a different product or modify disease control practices.

In general, disinfectants can be divided into seven major categories. A more detailed summary of the basic attributes of each category of disinfectants is available later in this discussion as "General Characteristics of Disinfectants". The various classes of disinfectants are:

  1. Alcohols
  2. Halogens
  3. Quaternary Ammonium Compounds
  4. Phenolics
  5. Coal Tar Distillates
  6. Aldehydes
  7. Oxidizing Agents

Although many disinfectants are available, those most suited for use in today's hatcheries include quaternary ammonium compounds, phenolics and aldehydes. However, each disinfectant is used only in appropriate locations for meeting the purposes for which it is designed.

Several considerations must be remembered when using any disinfectant to maximize its effectiveness. Some of these general considerations are:

Few disinfectants are effective instantaneously. Each requires a certain amount of time to bond with the microbe and exert a destructive influence. Allow adequate contact time (usually 30 minutes is sufficient) or select a different disinfectant.

When selecting disinfectants, consider their effectiveness on organisms that are of greatest concern. If a hatchery is experiencing problems with a certain viral disease, the disinfectant selected must be effective for destroying the specific organism causing the problem. Not all disinfectants are effective on all types or species of organisms.

In most situations it is advisable to clean and disinfect in two different operations that are separated with thorough water rinsing. Many cleaning/disinfecting producers promote their product based on ease and economy of use because they clean and disinfect in one operation. If these products are used, make sure that they satisfy all efficacy requirements demanded of other disinfectants.

The efficacy of disinfectant solutions is usually enhanced when applied in warm solutions rather that cold solutions. "Hot" solutions, however, may reduce disinfectant efficacy or promote a "cooked-on" condition for unremoved protein-rich residues.

When possible, allow all surfaces to dry thoroughly prior to reuse. Dryness helps prevent the reproduction, spread and transport of disease organisms. Although a surface is clean, it is more easily recontaminated with organisms if water remains on the surface.

A listing of important characteristics for the more commonly used disinfectants used by the poultry industry is shown in General Characteristics of Disinfectants.

It is important when selecting the best disinfectant to consider its effect upon the developing embryo and the hatchery environment. Embryos are in a very sensitive stage of development when the eggs enter the hatchery. They can be severely affected if subjected to chemical vapors, even if a sterile environment is provided.

It must be remembered that an egg is not produced in a sterile environment. Before it is laid, the egg is subjected to a series of microbial attacks that can reduce the embryo's potential to develop into a healthy, robust chick. The vent of the hen is probably the most contaminated area that an egg passes through. Poorly maintained nests can also distribute organisms to noninfected eggs. Fortunately, nature has provided several protective barriers for the embryo. Hatchery personnel must not conduct any procedure that interferes with the egg's natural defense. Producers must make every effort to collect and store eggs so that natural protections are not compromised.

Keeping egg shell surfaces dry is very important to prevent excessive microbial contamination and shell penetration. Without benefit of aqueous water the potentially dangerous microorganisms have little opportunity to invade the egg shell and infect the embryo. Sweating of eggs as they are moved from warm to cool environments must be prevented if sanitation programs are to be successful.

Embryos have the same requirements prior to pipping that the chicken have following hatching. They have the need for heat, moisture, and a high-quality source of air. They can be severely affected by harmful fumes originating from many chemicals often found in or near the hatchery. Although hatchability may not be affected, the quality of the chicken can be reduced. Whenever unusual odors from detrimental chemicals are detected in the hatchery, the product must be removed. This applies to all chemicals within the hatchery, including disinfectants. As an example, vapors produced by improper use of phenolic disinfectants can cause changes in egg proteins and impair hatchability and chick quality.

Improper selection or use of some disinfectants can damage or hinder the function of hatchery equipment. Many disinfectants are corrosive and damaging to equipment parts. Some disinfectants can clog and gum-up spray nozzles if added to the water used in humidifiers. It is possible that electronic control devices can also be severely damaged or destroyed after prolonged exposure to some disinfectants.

Select disinfectants wisely and always follow label directions for their safe use. Not only does management have the responsibility to maximize hatchability and chick quality, but also to provide a safe working environment for the hatchery personnel. Safety of the people working in the hatchery must never be sacrificed for cost or productive efficiency.

Assuming that a proper state of sanitation is achieved, it must be remembered that the status of disease-free surfaces can be compromised if facilities are not maintained properly. Hatchery personnel must be made aware that they can be a major source of reinfection by transporting of microorganisms on clothes, hands and attire. Since people are direct carriers of microbes, provisions must be made available at appropriate locations in the hatchery for the washing of hands and footwear. Laboratory coats and caps can significantly reduce the spread of microbial organisms. Restricting movement of hatchery personnel by assigning duties within specific areas can reduce the distribution of organisms throughout the hatchery.

The risk posed by disease causing organisms is a constant challenge to hatchery personnel. Always use control measures that have been proved effective rather than trusting visual cleanliness as an indicator of sanitation. A clean surface does not always indicate a disease-free state. Assuming so may be fatal to the chicken and the management program.

General Characteristics Of Disinfectants

ALCOHOLS (Isopropyl or Ethyl Alcohol)

  1. Wide germicidal activity, non corrosive, but poses a fire hazard.
  2. Limited residual activity due to evaporation.
  3. Alcohols provide limited activity in the presence of organic matter.
  4. Not considered effective against bacterial or fungal spores.
  5. Excellent for disinfecting instruments or other small objects.
  6. Too expensive for general use in the hatchery.
  7. Must use as a 70-95% concentration for effectiveness.

HALOGENS (Iodines or hypochlorites)

  1. Provide wide germicidal activity but are corrosive.
  2. Limited activity when in the presence of organic matter.
  3. Poor residual activity, low toxicity, but may stain surfaces.
  4. Not effective as sporocidal agents.
  5. Effective at low concentrations for disinfecting clean, small objects.
  6. Low cost but requires frequent applications.


  1. Limited germicidal range.
  2. Not sporocidal, effective against vegetative bacteria, fungi and viruses.
  3. Reduced efficiency in the presence of organic matter.
  4. Limited effectiveness in soaps, detergents and hard water salts.
  5. Non-irritating, non-corrosive and low toxicity.
  6. Residual activity is limited by the amount of recontamination.
  7. Good disinfectant for use on cleaned surfaces.
  8. Low cost.

PHENOLICS (Single or Multiple)

  1. Wide germicidal range, not sporocidal.
  2. Low toxicity and low corrosiveness.
  3. Very effective in the presence of organic matter.
  4. Good residual activity and deodorizer.
  5. Low to moderate cost.

COAL TAR DISTILLATES ( Cresol and Cresylic Acid) 

  1. Wide germicidal activity, not sporocidal.
  2. Corrosive and toxic at high concentrations.
  3. Excellent residual activity with heavy odor.
  4. Highly efficient in presence of organic matter.
  5. Not well suited for use near eggs or chicken due to noxious gases.
  6. Moderately expensive.

ALDEHYDES (Glutaraldehyde)

  1. Wide germicidal activity, sporocidal and fungicidal.
  2. Slight to moderate efficiency in presence of organic matter.
  3. Slight residual activity.
  4. Moderately toxic.
  5. Moderate cost.

OXIDIZING AGENTS (Hydrogen peroxide, Potassium Permanganate)

  1. Moderate to wide germicidal activity, not sporocidal.
  2. Rendered ineffective in the presence of organic matter.
  3. Moderately corrosive, limited toxicity.
  4. Poor to limited residual activity.
  5. More valuable as a cleansing and deodorizing agent.
  6. Moderate cost.






Ist Always

* Ist time introduced plastic setting Tray of Incubators in India in 1979.
* Ist time in India introduced Digital system.
* Ist time in India introduced setter of 30,000 egg capacity & 36,000 egg capacity.
* Now Ist in India introduced setter of 60,000 egg capacity & 90,000 egg capacity.

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Our Customers Views

" The setters of 36,000 eggs capacity installed by you are giving good results as well as the quality of chick is also very good. "

Dr. Pradeep Kumar - Senior Consultant V.K. Hatcheries Ajmer (Rajasthan)

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