All You Need to Know About Incubation

Tuesday, November 10, 2015

The Basics of Incubating Chicken Eggs

We have been hatching eggs for over a decade now and there are a two things we have learnt, the first is no two hatches are ever the same and the second is; there are no words to describe the wonder and joy of new hatchlings! We get asked numerous times each season endless questions on incubating and hatching. So we are finally getting round to putting our experiences in a news article so we can help others that wish to experience and enjoy the delights and pitfalls of incubating in an incubator.

What do I hatch in?
We definitely recommend using the best incubator you can afford. Investing in a reliable, trusted brand makes a huge difference in the success rate of your hatch and all those that follow. Avoid cheap, made-in-China incubators. These usually do not hold their temperature or humidity well as constructed out of inferior materials with poor insulation qualities. We have experienced and heard many times that these cheap incubators appear to work fine the first couple of hatches and with each consecutive hatch the success rate declines. We recommend and use Brinsea Incubators, have done for years. We have an Incubation Room dedicated to these yellow incubators! We have been setting and hatching in these for years and the results are consistently good. Brinsea is a well-established, reliable, UK brand that performs well time after time. They have perfected temperature control, have excellent insulation, good ventilation and reliable tuning mechanisms. It also good to know that Brinsea stand by their machines and offer an extended 3-year warranty on all new Brinsea incubators. So if you take hatching seriously and are going to invest time and money in your hobby then invest in the best: Buy a Brinsea. They have an extensive range of incubators from the Brinsea Mini Eco that takes 10 chicken eggs with manual turning right up to the Brinsea Ocatgon 580 Adance Ex which hold hundreds of eggs with auto turning. Now available for sale on our website.




What size Incubator?
Choosing the right size incubator is as important as buying the right brand. Mini Incubators that hold a handful of eggs might be good value at a couple of hundred dollars but to get a good number of pullets from one hatch is not going to happen! It will take a few hatches before you have a decent laying flock. All these different hatches will require time and money running the incubator and heat source.

For example:
7 hatching eggs = 1 clear, 1 blood ring, 1 not hatched (-3)
So 4 hatch, one chick is lost in week 6 leaving 3 to raise through to POL.
2 turn out to be cockerels which leaves 1 pullet.
Six months to produce 1 single hen!

Mini Incubators are great for schools and kindergartens or for families that wish to show children the wonders of hatching. They are an excellent education tool with clear viewing or as a backup if you have broody hen, but for those that wish to hatch out a decent number of chicks and wish to add to their laying flock then an incubator that takes 24 eggs makes lots more sense. The ratio we have come to use over the years is: Set 24 eggs to get 6 POL pullets (point of lay). Remember you will need to grow your progeny on to maturity (POL) so getting them hatched is only really the start of the journey. A good size incubator that takes 24 eggs will cost more but you will save huge once they are hatched. Just remember you will only need to run the heat lamp once and take one lot of chicks through to POL rather than running all the equipment many times for smaller batches. One bigger hatch involves a lot less work. In the smaller incubators like the Brinsea Mini and Brinsea Octagon 20 hatching and setting in the same incubator (machine) works well. We advise setting the incubator to capacity for best results and then candling at day 7 to 10 to remove the clears and early deaths. Candle again on day 18 to remove any blood rings or mid/late deaths. This gives the chicks a little more space when it comes to hatching.

Best Time of Year?
The breeding season runs from late winter/early spring to late summer. Hatching eggs are best incubated in the first half of the season. Eggs set prior to Christmas will grow in the length of the day and do better than those hatched in February, March or April when the days are getting shorter. Fertility and hatchability drops off towards the latter part of the season as birds relax, the weather becomes warmer and finally the moult sets in. We recommend hatching from July to December for best growth in young stock. 

Hatching Eggs
There are some important factors to consider with hatching eggs also called fertile eggs. Hatching eggs are the eggs collected from the breeding pens where a rooster is running with hens. Most should be fertile if the rooster is ‘doing the business’ but there is no guarantee. Factors like age of hens, range, environment, stress, number of roosters, in-breeding, weather, health, injury and feed quality all play a part in the fertility and quality of the hatching eggs. Changes in weather do impact on fertility. We know vitamin D is very important for good fertility. Prolonged wet weather, too much wind can keep chooks sheltering in hen houses and the roosters are not necessarily as active. Quality feed goes a long way to making good, strong growing peeps that are going to develop through to Day 21 so ensure you buy hatching eggs from a good source.

Where to Source Eggs?
Best sourced from a reputable breeder. Look for eggs from fowls from quality stock with the correct breed attributes. The New Zealand Poultry Standards compiled by Ian Selby is the ‘chook bible’ when it comes to what is correct and what is considered a fault in a breed. Breeders will be setting and hatching regularly so will have a good idea of the fertility in their poultry pens. The only way to monitor fertility is to incubate and hatch regularly. It is impossible to know which eggs are potentially fertile and what are going to be pullets just by looking at the egg or shape of the egg!
Here at Appletons our Hatching Egg availability is regularly updated on our website. 

How Many Eggs and for How Long?
Check on the incubation period/s of what type of eggs you are setting. Chicken eggs take 21 days to incubate. Duck are 28 to 30 days. Guinea Fowl are 27 to 28 days. Golden Chinese Pheasant are 22 to 23 days. Setting a full incubator works best. The benefit comes when the eggs are hatching and the chicks all pip and breathe for the first time – this assists the hatch increasing the humidity and preventing the membranes on hatching eggs from becoming too dry.

What Breeds of Eggs?
Best to set all similar classifications of fowl together. Even if they are all chicken eggs and roughly take the same time to hatch it is the growing process from hatch day on that can cause issues. Pecking and bullying often being the common issues. We have found over the years (and we are hatching good numbers of chicks) that we get the best results raising similar breeds together with similar natures. For example: raise dual purpose breeds alongside each other and the same with light breeds. We prefer to keep the bantams separate from the larger breeds as they are just smaller and have different natures. And the same can be said for ducks, guinea fowl and pheasant. They are all best raised with their own kind. Ducks are best raised separately from chickens mainly from the point of view of wetness! They love water and make brooder boxes very wet and soiled and smelly very quickly. We find raising ducklings on a wire floor keeps them clean and dry. However, If doing very small hatches this is not usually so much of an issue as less birds and more space can alleviate some of these issues.

How Long can I Store Hatching Eggs?
We set hatching eggs in our incubator every 7 to 10 days for best results. Holding eggs for up to 2 weeks prior to setting is also fine as long as stored correctly. Three weeks is stretching it a bit but can be done please note that the overall fertility and hatchability will decline the longer you hold them.

How to Store Hatching Eggs?
Hatching eggs should be collected daily from breeding pens and stored correctly for best results. Eggs should always be stored with the pointy end down while they are ‘in the hold’ or on their sides as they would naturally sit in the nest. It's a good practice to follow and it will help your hatch. Do not write on them in felt tip or permanent marker as this will affect the fertility as eggs are porous. Don’t wash or clean hatching eggs. The cleanliness, soundness and integrity of the egg shell influence the hatch. Do not set cracked or eggs with thin areas where inadequate calcification has occurred. Cracked or thin shells allow microbial contamination and excessive evaporation from the egg during storage and incubation.  Washing removes the protective cuticle, making the egg more susceptible to contamination. We store ours in the garage which is cooler than the rest of the house but not as cold as in the fridge. Whether receiving eggs via courier or collecting your own for hatching correct storage is worth the effort. We sit ours ‘pointy end’ down in trays or dozen cartons in the garage and rotate the them ‘end to end’ twice a day.Hatching eggs will need to settle for 24 hours if they have been sent via the courier/mail. This allows the air-cell inside the egg to return to its normal size. Eggs should always be stored with the pointy end down while they are ‘in the hold’.

Ready to Set!
Set the incubator up and get it running for a day prior to setting your eggs. Sit your eggs in the same room so they warm up to room temp. prior to popping them in the incubator. This avoids thermal shock. Make sure the incubator is in a room which has a pretty even temp 24/7 - all day and all night. Best not to incubate in outside sheds, shipping containers or sunny rooms where temperatures can spike or plummet.  Avoid direct sunlight on the incubator and no draughts.  By running the incubator for a day prior to setting allows you the opportunity to check that the temperature, humidity and ventilation are where they should be and also to make sure the turning mechanism is working properly (if you have one!).

The 5 Key Words to Incubation
Temperature: The egg must be maintained at the right temperature to enable the metabolic processes within the developing embryo to occur at the correct rate.
Humidity: The egg loses water through pores in the shell. The humidity of the air around it must be controlled to ensure the right amount of water is lost over the incubation period.
Ventilation: The egg “breathes” so there must be a supply of fresh air to provide oxygen and to remove waste carbon dioxide.
Turning: The egg must be frequently turned and carefully positioned so that the embryo passes through fresh nutrients in the white of the egg, while forming in the correct position for hatching.
Cleanliness! Eggs are susceptible to infection so the incubator must provide a clean, disinfected environment.
All are vital to a good hatch. Get one wrong and this can affect the success of your hatch.

Temperature is very important. At the centre of the egg this should be 37.5 degrees Celsius. If the temp is running slightly low or slightly high this will slow down or speed up the hatch. If the temp drops too low or spikes too high this can cool or cook the embryos and all can be lost. So maintaining an even temp is very important. In a still air (non-fan assisted incubator) where the air is not circulated the temp at the centre of the egg will need to be 37.5 degrees so if the bulb of the thermometer sits just above the egg the temp will read 39.2 degrees C. In all modern fan assisted incubators where the air is constantly circulated the temperature will read 37.5 degrees. Brinsea’s range of digital incubators are calibrated to hold the temperature ‘spot on’ and will alert you via alarm should the temp drop below or spike too high.’

 Humidity and Ventilation
This can vary hugely depending on where you do your research. Here at Appletons we incubate all our chooks eggs at 40 degrees RH. This RH % works well for us. Humidity is directly linked to the surface area of water in your incubator. Increase the surface area and this will increase the RH. Let your water source dry up and this will reduce your RH quickly. The humidity levels in your incubation room and external environment (the weather) will indirectly affect the humidity in your incubator via the ventilation holes. Humidity constantly changes with the climatic conditions (seasons) and we have found this to be factor worth considering when incubating all year round. The egg “breathes” so there must be a supply of fresh air to provide oxygen and to remove waste carbon dioxide. Air needs to circulate in an incubator and chicks will ultimately need to breathe on pipping so ventilation is very important. Most incubators have small holes which allow this exchange of air. Open them up and this reduces humidity. Close them up and this helps to increase humidity. Closed ventilation holes will cause high carbon dioxide in the incubator as once the chicks start hatch they breathe and take in oxygen and breathe out Co2. So getting the balance right between humidity and ventilation on hatching is important.

Mother hen sitting on her nest and uses her feet and wing butts to giggle around and turn her eggs regularly so they all get equal opportunity to contact her skin, retain a constant warmth and most important of all the growing peep inside the eggs get regular turning which keeps the peeps fit and healthy and so they do not stick to the inside of the shell. The egg must be frequently turned and carefully positioned so that the embryo passes through fresh nutrients in the white of the egg, while forming in the correct position for hatching. All important for the growing peeps. Most basic incubators require manual turning. This means that twice a day you will need to turn the eggs. These days most incubators come with some sort of mechanized turning system. Either a tray that rolls backwards and forwards under rods that hold the egg in a fixed positon and as the tray slides so the eggs get rolled. Other incubators sit in a cradle which rocks the entire incubator from side to side or in the newer cabinet style incubators the trays tilt from side to side. Our recommendation in the manual turn incubators it to use some of our Chick Mat on the base tray so the eggs do not slip and slide around and just using your hand you can roll the eggs to a new position twice daily

Incubation Period of Chicken Eggs is 21 days
Day 1: set eggs
Day 1 to 18: Check regularly that the required water channels/reservoir is topped up to maintain correct RH.
Day 7 to 10: Candle eggs – remove clears and blood rings
Day 18: Stop turner/remove turner – candle again, remove any ‘death in shells’. Place ‘ticking’ eggs on chick mat in incubator, Top up all necessary water channels/reservoirs to increase humidity and shut incubator. Please keep necessary ventilation holes open.
Day 18 to 22: Leave incubator alone. Do not open for any reason until 24 hours after the end of hatch day (this is day 22).
Day 22: Open. Remove all live, fluffed up chicks to the brooder box, remove all shells, check all unhatched eggs for forms of life, remove dead ones and close up incubator
Day 23: Remove last few chicks. Candle unhatched eggs. Most will be dead in shell/ late deaths.

Candling Eggs.
This makes the process more interactive and adds a whole new dimension to hatching! There is nothing like seeing what is going on inside each egg. We use and recommend a Brinsea Ovaview Candling Lamp which floods the egg with light. Best to use an LED or cold light as too much heat can harm the growing peeps. Brinsea also have a High Intensity Candling Lamp which is perfect if candling brown or dark shelled eggs like Rhode Island Red, Barnevelder or specialist eggs like Pheasant eggs. An egg at Day 1 is clear. When candling at Day 7 to 10 you will notice a small collection of blood vessels leading to a small, dark pulsating dot which will react slightly to light and heat. Looks a bit like a little red spider! This is the start of your peep. As it grows and develops it creates more blood vessels and becomes a more solid mass within the egg. The air sac will slowly increase in size and by the time the chick is ready to hatch the air sac can take up 1/3 of the egg. We recommend candling again at Day 18 and removing the eggs that have died. In late deaths the blood vessels are no longer red and the egg shows no movement and looks dark and dull. We remove these from the incubator which gives the soon to hatch chicks more room as they emerge. We candle again after Hatch Day (21) on Day 22 and 23 to confirm that all the non-hatchers are dead in shell prior to ceasing the incubation. It is good practice to open up unhatched eggs to see why chicks have died in the shell. (Eggtopsy)


Brinsea's Guide to Candling Eggs

Losses During Incubation 
Most young that die in the egg usually die either in the first few days of incubation, or alternatively the last few days of incubation. In the first few days, embryo death is usually due to either inadequate incubation leading to too low a temperature to keep the chick alive, excessive jarring of the egg that either fatally damages the chick or yolk, or alternatively, a genetic problem affecting the chick which is incompatible with life. Towards the end of incubation, chicks usually die as a result of problems associated with hatching. As incubation ends; the chick has to shift from getting its oxygen through the membranes that surround it, to breathing air. It also re-absorbs its yolk sac which supplies it with both food and immunity. If the temperature or humidity is incorrect at this time these processes fail to occur correctly and the chick can die. Between the beginning and end of incubation, the chick is essentially just growing and it is here that nutrition and infection become more important. If the young chick is lacking a nutrient it needs for growth or becomes infected; it may die. For those of you having a problem with dead-in-the-shell youngsters, let’s have a look at the potential problems that can arise with each of these periods of incubation in more detail, so that hopefully the problem can be solved.

Embryonic Death At The Start Of Incubation
Deaths early in incubation can be detected by opening the egg and seeing that it is in fact fertile, but that the embryo is only poorly developed. This can be due poor health and/ or diet of the parent stock. Embryos that are unlucky enough to have genetic abnormalities usually also die early in incubation. Genetic problems are more likely to occur with in-breeding.

Deaths From Day 4 To Day 14 Of Incubation
This is the longest period of the incubation process and yet it is the time when least deaths occur. The embryo is simply growing. The growing chick receives its nutrition from the yolk and deaths here can reflect nutritional problems in the hen. Hens that are correctly fed are more likely to produce nutritious yolks that support healthy embryos.

Embryonic Deaths At The End Of Incubation
Through incubation a membrane called the chorioallantois develops around the chick. The chorioallantois acts a bit like a human placenta, in that it delivers air to the embryo after it diffuses through the shell. At the end of incubation, the chick must swap from a chorioallantoic respiration to breathing air. It does this in two stages. First it internally pips. This involves cutting a small hole into the air chamber at the end of the egg and starting to breath the air it contains. At this stage vibrations can be felt in the egg and chick will sometimes vocalize. After another 12-36 hours the second stage begins, with the chick cracking the shell and breathing external air. While this is happening the last of the yolk sac which is the chick’s nutrition during incubation, is drawn into the navel. Interestingly, during this time, the chick also drinks the clear fluid around it called the amniotic fluid. This amniotic fluid, and also the yolk sac contain the antibodies that protect the chick from infection in the first few weeks of life. While all this complex physiology is going on the chick is vulnerable to problems. Too high or low temperature or humidity during this time will adversely affect the chick. The usual problem is too high a temperature, or too low a humidity. This combination causes the shell and shell membrane to become hard and dry. This can lead to a healthy chick becoming exhausted. In addition to this, the chick quickly becomes dehydrated. I am sure many of you, myself included, have helped these chicks hatch only to find them dead later. These chicks often die because they are dehydrated. Such chicks if given small drops of water will often suck them down greedily and survive. These dehydrated chicks are called “sticky chicks” because of the way they stick to the dry shell membranes. They are often found dead after hatching ¼ to half the way, emerging from the shell. If removed from the shell they often have unabsorbed yolk sacs and there is often dry, gluggy albumen still in the egg.

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 or 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. We call these chicks shrink-wrapped. 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 chicks that are hatching. When hatching begins and proper incubator conditions are attained, the incubator should never be opened until after all chicks are hatched and ready for placement in the brooder. This is really important we call it the Golden Rule: Never Open the Incubator to Assist Chicks During the Hatch Stage.

Cleaning and Storing Your Incubator

There is no exact science to hatching. With every new hatch (and we hatch weekly!) is still great excitement (or should I say eggcitement!) Fluffy chicks in whatever numbers are loved, appreciated and grown on either to be good layers or handsome cockerels!

Happy Hatching!


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Incubating chicks

I would like to thank you so much for the clear and concise instructions for hatching chickens. I have had several chook books and none of them have given me such detailed information as well as the things that can go wrong and the reasons. I have printed out your info and will refer to it often. thanks again for your help , Roselynn Waldman, Whakatane