How to Hatch Chicken Eggs

Learn How to Take Care of Baby Chicks Before They've Hatched

How to Hatch Chicken Eggs

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By Don Schrider – It is time to begin preparations for breeding and collecting eggs for hatching. Anyone can have great success in learning how to hatch chicken eggs; all that is necessary is to provide good conditions that work in accord with the nature of the birds, and the cycle of reproduction. So where do we begin?

We start with the breeder birds. When mating birds, it is important to know and manage relationships within your flock. To avoid inbreeding bottlenecks, we want to avoid close genetic relationships — such as full brother to sister matings. We want to limit the use of close forms of line breeding — such as sire to offspring or dam to offspring — so that this form is infrequent or represents a small portion of the overall genetic relationships. But some line breeding is not bad and can result in fixing undesirable traits within our lines.

For those who want to learn how to hatch chicken eggs and have started with chickens from hatcheries, or a pair or trio from a breeder without knowing if any of the birds are close relatives, start “where you are with what you have,” (to quote the famous barred Plymouth Rock breeder, Ralph Sturgeon) and thereafter manage your flock’s genetic relationships.

I find it helpful to keep in mind that breeding’s first and primary role is to produce the next generation while maintaining enough diversity to be able to continue to do so long into the future. Culling and selection are where improvements to the flock are made.

The pitfalls of genetically close relationship — such as full brother to sister mating — is that they can result in poor fertility, poor hatch rates, or the frequent appearance of genetic defects.

(For more on breeding methods, see “Selective Breeding Applied” by Charles Everett.)

Start with Healthy Birds

Now let’s consider the birds themselves. Roosters can and should be fertile up to five or more years of age. I’ve known a few roosters that were fertile even at the age of nine — but such are rare exceptions. They need to feel good about themselves in order to perform their role well. A rooster that is picked on will breed fewer hens and generally have less interest in breeding than a male that believes he is the “king of the world.” It takes about 3-4 weeks for a male’s view about himself to change. I’ve noticed that very old males need roomy pens to be fertile, and best results will occur when used in conjunction with young females and warm weather. The male also needs to be free of parasites, such as mites, lice, or worms, in order to be reproductively healthy and willing.

Cochins are a breed with dense feathers that can get in the way of a successful copulation. Trim back the feathers above the hen’s vent, and below the male’s vent. Photo courtesy of John Layton, New Jersey.

Some additional thoughts on roosters and mating: Fertility is often low on roosters with comparatively small vents. Roosters often will not mate on wire-floored pens. Heck, the hens aren’t too keen to mate on wire-floored pens either. During mating, it is the toenails of the roosters that most often cause broken feathers and bare spots on the backs of the hens. You can trim their toenails to prevent feather damage and, for heavy breed males, to prevent them causing wounds to the hens’ backs. When a rooster suffers frostbite on his comb or wattles, it causes a fluctuation in his body temperature and results in a lack of fertility lasting about 30 days.

Next, let’s look at the hens. Hens generally have reliable social structures and most hens will be comfortable with their placement within the flock’s pecking order. Our main concern here has to do with the hens at the very top and the very bottom of the pecking order. Hens at the top of the pecking order have virtually unrestricted access to food and water. Such hens can often become overly fat. You can check the body condition of a hen by feeling the thickness of her pelvic bones. (See “How to Get More Eggs,” Backyard Poultry April/May 2010 issue.) Hens at the bottom of the pecking order are stressed more often than other hens and have less access to feed; this will be less manifest in smaller flocks and more noticeable as flock size grows. Overly fat hens do not lay well; overly thin hens do not put as much nutrition into their eggs. Young hens have the advantage of being better able to retain semen in a viable state, and are more likely to lay fertile eggs. Old hens lay fewer eggs but also express longevity and proven performance. Old hens will be very fertile with young males. Hens should also be free of parasites such as lice, mites, and worms, not only so that they may keep their egg production high, but so that they do not infect males with these vermin.

Monroe Babcock, the originator of the Babcock B2000 industrial Leghorn, observed that in cases were fertile males mated with fertile females, but that the eggs had low fertility, the fault lay not with the male but with the female; it seems that the hen’s ability to keep the semen viable was the contributing factor. Walter Hogan observed that the shape of the pelvic bones made a difference in fertility — on some birds the bones curve inward toward each other, this being not desirable. Mr. Hogan noted that fertility was higher on birds with straight pelvic bones and that males, whose bones turn in almost like horns, were not very fertile with hens with nice, straight bones.

Consider Nature’s Breeding Cycle When Learning How To Hatch Chicken Eggs

I always mention nature as I write about birds; so let’s think for a moment about the natural breeding cycle. As sunlight increases in the spring, it acts upon the males and causes their bodies to produce higher levels of hormones. This causes them to become more active and more interested in mating. Sunlight also causes higher levels of hormone production in the hens, resulting in more eggs and the desire to nest, aka getting broody. At the same time grasses spring forth and the diet of the birds will include bits of this fresh grass and the higher levels of vitamins, such as A and D, that it contains. Insect activity also manifests, and the birds’ diet will include more protein.

Feed, Vitamins & Supplements for Breeder Birds

Breeds with large breasts, such as this Cornish, can have problems mating due to chest mass. Photo courtesy of Matthew Phillips, New York.

Let’s take a look at what to feed chickens as we try to imitate nature while we manage breeding and learning how to hatch chicken eggs. Standard laying mash should be considered not as a premium feed but as a cut-rate, bare-bones, minimum level of nutrition. It has been formulated over the last 100 or so years to provide just what hens need to stay in laying condition — there has been no consideration for the nutrition it passes on in the form of the eggs. To have the best results in hatching, we need to feed our flock better than this level. Fortunately, we have better quality feeds and supplements that can aid in providing optimum breeder nutrition. Most feed companies offer a Game Bird Breeder Layer mash (crumble, pellet). Such a feed has a boost in vitamins and is usually higher in protein and fat. Yes, fat is needed in the diet of breeder birds, it is necessary for the digestion and absorption of protein. We also find that all animals reproduce best when not too fat and not too thin—maybe the results of being in balance with their environment.

Some excellent supplements can be added to “plain-Jane” layer mash when Game Bird Breeder feed is not available. An excellent supplement is Omega Fields’ Omega Ultra Egg. It is largely flax seed meal with extra vitamins added. It boosts Omega-3 values, mimicking the effects of a diet that includes prime, spring pasture. Other excellent supplements include wheat germ oil with vitamins A & D added, cod liver oil, and Fertrell’s Poultry Nutri-Balancer.

Fertility Varies Among Breeds

Placing a blanket over the incubator (without blocking the vents) can keep temperatures stable and reduce electric bills.

Now that we have taken a look at feeds, let’s move on to breeds. While most breeds of chickens are capable of natural reproduction, breed can play a role in fertility rates of the eggs. Breeds with very fat feet and large breasts, such as Cornish, can be hampered in fertility, especially if males of such are mated to females that cannot handle their mass or that are shaped such that copulation becomes difficult. The Wyandotte is a good example of a breed that is very fertile — except during winter months when the males are seldom interested in the females. It would seem that sunlight stimulation is key here. Cochins are a good example of a densely feathered breed for which copulation is sometimes unsuccessful due to the feathers preventing contact. An old Cochin breeder, Johnny Arbaugh, once told me that to solve this issue you should pluck the feathers below the male’s vent and above the female’s. Often when breeding is seen but eggs are not fertile, the underlying problem is this blockage by the feathers. A quick examination of your hens will usually show evidence of mating on the feathers of the vent.

Temperature and the Egg

Size of air cell on 7th, 14th and 18th day of incubation. Courtesy of Mississippi State University Dept of Poultry Science,

Temperature plays a great role in successfully planning for how to hatch chicken eggs. Older males and males of some breeds will not mate during cold weather. Likewise, males of some breeds will not mate in the dead heat of late summer. I would not expect Brahmas or Cochins to be highly fertile in late summer. But I know from experience that Leghorns will mate in triple digit temperatures. I once saved a clutch of eggs for Frank Reese of Kansas when he came east visiting. The temperatures were over 100°F during the days, but 42 of the 46 eggs collected during this time hatched when Frank returned home.

Breeds with naturally high levels of broodiness, and conditions where many hens prefer to use one nest, can result in eggs being warmed to the point of growing for just a few hours and then cooling down again. This change of temperature can shock the delicate embryo, especially when nutrition is basic/poor, and result in apparent infertility or many embryos that grow for the first few days of incubation and then die.

Peter Brown, aka the Chicken Doctor, once shared a great wisdom with me — eggs are pregnant. From the time they are laid until they are warmed to incubator temperatures, the embryo inside an egg is growing very slowly. When an egg is warmed to 99-100°F the embryo begins growing “quickly.” If the embryo is not growing, even microscopically slowly, then it is dead.

When eggs are chilled for several hours they often fail to produce live embryos. Traditionally, eggs in winter were collected several times during the day — to prevent freezing and heating and cooling as hens entered and left nest boxes. Eggs that are warmed and then cooled one or more times often fail to grow. Eggs for hatching should be stored in a cool location, out of direct sunlight to avoid temperature fluctuations. Ideally, eggs being stored for hatching should be held between 50-60° F.

Daily changes in the weight and form of the developing chick embryo (White Leghorn). Courtesy of Mississippi State University Dept of Poultry Science,

Most us will also want to know who the daddy is when learning how to hatch chicken eggs. It takes 24-26 hours from the time the yolk is released (ovulation) until the egg is formed. Fertilization happens in the first 15 minutes of ovulation, but it is a total of about three days until a fertile egg is laid. Once a rooster mates with a hen, generally it is found that all the chicks from the fertile eggs laid, beginning three days later, will be his offspring. When a new rooster is used on a flock, it is best to wait two weeks before saving eggs to be sure that he has mated with all the hens — then you can be sure who the sire of the chicks will be. In cases where a valuable male has been lost, fertile eggs from this male can be laid even three weeks, or more, after he last mated; keep saving and don’t let another rooster mate the hens.

How to Hatch Chicken Eggs: Careful Egg Preparation & Storage Means Success

So we now have eggs from well-mated chickens on a breeder diet for our experiences in learning how to hatch chicken eggs. Our breeder birds have plenty of exercise and are free from vermin. We collect the eggs each day before they can become chilled and we store them in a cool location (55-60°F) with a constant humidity. What else should we consider for how to hatch chicken eggs?

I always store my eggs in a cellar or room with no sunlight that could raise their temperature. A cooler works very well to keep the eggs stable with a constant humidity. With one, you can place a board under one end, switch the board once per day, and thus rotate the eggs with little effort. Maintaining humidity is important as the eggshell is porous and eggs are designed to lose a little moisture before hatching, but if they lose too much the paper liner of the shell becomes too tough and the chicks cannot get out of their shells.

Eggs that are stored properly will hatch even when saved for 3-4 weeks. Best results are observed when eggs are saved for just 10 days, though saving for two weeks is easier to track for how to hatch chicken eggs when multiple hatches are planned. Since it takes three weeks for eggs to hatch, when using one incubator you can save eggs for two weeks, set, eat your eggs for a week, and then save two more weeks of eggs for the next setting. For optimal results, eggs should be allowed to warm to room temperature for 4-6 hours before setting. Eggs just laid should be allowed to cool to room temperature for this amount of time as well before being set.

While we are speaking of setting eggs, another important part of how to hatch chicken eggs is to realize that culling of your flock starts with the eggs. Discard all misshapen eggs, eggs that are long and thin, eggs that are too round, eggs with rough or thin shells, and eggs heavily soiled. Eggs with cracks will often have bacteria penetrate them, causing them to rot and possibly explode in the incubator. Once you’ve experienced a rotten egg explode, you will never forget it! Dr. Al Watts of Washington State once told me that he drips the wax of a candle along the cracks and is able to hatch from eggs with light cracks. I’ve tried this and it works. Heavily soiled eggs are simply bringing large doses of bacteria into the incubator while their pores are largely blocked, and are less likely to produce a live chick.

Follow the incubator manufacturer’s instructions. House the incubator out of direct sunlight and away from any drafts.

How to Hatch Chicken Eggs: Prepare Incubators for Successful Hatch Rate

Your incubators must be set up in a location without direct sunlight — incubating chicken eggs in this manner will prevent temperature fluctuations, and with a constant temperature. Incubator manufacturers never seem to have thought of insulating their products. I usually throw a blanket over my incubators, without blocking the vents, and joyously have found lower electric bills and very successful hatches as a result. A blanket can save your clutch if the power goes out during incubation – often the hatch will be delayed and not lost, just give it a few extra days. Seldom does an incubator perform correctly in a garage or barn — nighttime temperatures in early spring are just too low for the incubator to maintain internal temperature. My friend, Raymond Taylor of Virginia, built an insulted, small closet in his garage for his incubator when he was learning how to hatch chicken eggs, and this proved very successful.

Follow the incubator manufacturer’s instructions on operating your incubator. Generally, still air incubators run at 101°F and forced air at 99.5°F. Run your temp a little low and the hatches will be delayed, run it too high and the hatches come early. Bob Hawes of Maine has noted that hatchability is reduced by 4% and the hatch is delayed by half-an-hour per day beyond four that eggs are saved. My neighbor, Paul Seymour of Virginia, has observed that lowering the temperature by half a degree results in more females and raising it half a degree results in more males. The jury is out on exactly how this works, but it seems that the lower temperature results in fewer of the male chicks hatching, and just the opposite for the higher temperature. Studies show that chicks left in the incubator for 24 hours after hatch suffer less from heat stress as adults.

Humidity is an important part of how to hatch chicken eggs. Get it too high and the eggs do not lose enough moisture before hatch — the result is chicks whose navels have not sealed and many chicks that pip but then “drown” from the moisture that collects at their nostrils. The chicks will also have a pasty appearance because not enough moisture evaporated from their down when they hatched. When humidity is too low the paper membrane of the egg will toughen and many chicks will not make it out of the shell. Such chicks will have shriveled, thin legs and are more prone to dehydration the first two days in the brooder.

Incubation takes three weeks. During this time, eggs should be first placed pointed end down and then rotated every eight hours. We want the pointed end down, as we need the air cell to remain at the top of the egg. If the air cell develops malposition from being placed downward during storage or incubation, the chick will not be able to hatch. We rotate the eggs so that the embryo does not stick to the side of the shell. Rotation stops on day 18. At this time most incubator manufacturers recommend raising the incubator humidity a little for the last three days prior to hatch — this helps ensure the paper membrane can be penetrated by the chick. The incubator itself should not be opened for fear of reducing humidity. If you have to open it, make it quick and spray a bit of mist in with a spray bottle. When the chicks start hatching, do not open the incubator. Many of us wish to hold that first chick, but the sudden drop in humidity may result in many others pipping but not hatching. Resist temptation!

What Goes Wrong When Learning How to Hatch Chicken Eggs

Even with the best of preparations, sometimes things go wrong when learning how to hatch chicken eggs and some eggs fail to fully hatch for several reasons. Malposition of the air cell is highly heritable and causes most of the cases of a chick growing to full-term without hatching. The chick must grow and be in proper position or it struggles and will not extricate itself from the shell. In nature, such chickens do not hatch. Don’t help them out of the shell! First, we do not want to increase the incidence of malposition of chick or air cell in our flock. Second, the struggle to hatch causes the chick’s metabolism to speed up—in particular, it is a struggle for the circulatory system. This is necessary to have healthy chicks that grow into productive, healthy adults. Helping these “weaklings” out of the shell seems kind, but works against nature and handicaps future generations. Also, chicks that have been unable to remove themselves from their shells often will have tendon issues. Once chicks exert themselves and their metabolism increases, the tendons start to set — if this happens while the chick is in the shell, then crooked toes and even bow legs can and do usually result.

Work with nature and match her ways closely and we will all have success with learning how to hatch chicken eggs.

Don Schrider is a nationally recognized poultry breeder and expert. He has written for publications such as Backyard Poultry, Countryside and Small Stock Journal, Mother Earth News, Poultry Press, and the newsletter and poultry resources of the American Livestock Breeds Conservancy.

Originally published in 2012 and regularly vetted for accuracy.

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