How to Produce Eggs for Hatching

Chicken eggs that are destined for hatching are, appropriately enough, called hatching eggs. They are simply fertile eggs that will hatch when properly incubated. Table eggs (eggs for eating) differ in that they may or may not be fertile. Fertilization requires the presence of a rooster.

That means you don’t want to try to hatch eggs from a grocery store. Those eggs are generally not fertile. But even if they were, they probably wouldn’t hatch because they have been stored too long to remain viable. Plus, they’re refrigerated, suppressing any potential embryo.

Purchasing hatching eggs from hatcheries, poultry keepers and speciality breeders

Some of the most common sources for hatching eggs are mail-order hatcheries, fellow poultry keepers, and specialty breeders. Shipped eggs may encounter any number of problems that will affect their hatchability. Here are some of the more common issues:

• Poor packing, which can result in cracked or broken eggs
• Rough handling, including bouncing around in a mail carrier’s delivery vehicle
• Subject to summer heat or winter freezing
• Transported in a plane’s non-pressurized hold
• Staying in transit for too long

Despite these potential setbacks, shipped eggs still may satisfactorily hatch. Last time I ordered eggs for hatching I was pleased to get a 50 percent hatch rate.

Hatching shipped eggs

If you order hatching eggs by mail, give them time to settle before placing them in your incubator or under a hen. Settling gives the eggs a rest after being jostled during transport. It also lets them adjust to a uniform temperature before incubation starts.

Let the eggs settle for at least half a day. You won’t get the same hatch percentage from shipped eggs as you would from fresher eggs that aren’t subjected to the rigors of transport. But settling should improve your percentage rate compared to eggs that aren’t settled. 

Regardless of where you get your hatching eggs, they are unlikely to come with any kind of guarantee. Even if the eggs are perfectly viable at the time you obtain them, incubation is tricky business. Any number of things can go wrong between day one and hatching time.

Collecting eggs to hatch from your flock

Collecting hatching eggs from your own hens is the best way to ensure they are fresh and handled properly to keep viability. It also reduces the chance of introducing a disease into your coop.

Collect eggs at least three times a day. Frequent collection minimizes the eggs’ contact with dirty surfaces. And it keeps them from chilling or overheating, both of which would reduce their hatchability.

Avoid incubating a young pullet’s first egg, which is less likely to hatch than later eggs. Regardless of a hen’s age, the same is true of any egg that starts a new clutch after the hen takes a few days off from laying.

As hens age, they expect the hatchability of their eggs to gradually decrease. Likewise, male fertility gradually decreases with age.

When is hatching season

A breeder flock is strongest and healthiest in spring. That makes spring chicks the strongest and healthiest as well. And chicks that hatch in cool spring weather have time to gradually develop immunities to germs that proliferate with the approach of warm, humid summer weather.

When collecting eggs for hatching, look for these qualities:

• They are clean and unstained when gathered from the nest
• The shells are smooth (not rough)
• The shells lack wrinkles, cracks, or thin spots
• The eggs are of typical size and shape for the breed

What egg size to look for

The size of an egg depends on the size of its yolk. And the size of the yolk is relative to the size of the hen.

Geese and turkeys lay larger eggs than chickens and ducks, which in turn lay larger eggs than guinea fowl and bantams. Within each species big, healthy hens generally lay larger eggs than smaller, less vigorous hens.

Pullets start laying small eggs. Even after their eggs increase to normal size, sometimes the last egg in a clutch will be small. Eggs that are smaller than normal generally produce smaller, less vigorous chicks.

Excessively large eggs tend to hatch poorly. And those that do hatch may result in chicks that have unabsorbed yolks (soft bellies that don’t heal) or inconsistent growth rates. 

What to look for in egg shape

An egg takes on its shape at about the same time as it gets its shell, which occurs in a hen’s shell gland or uterus. Eggs laid by a particular hen therefore are, with occasional exceptions, pretty much all the same shape. Since egg shape is hereditary, hens within the same family lay eggs that all have basically the same shape.

A healthy hen has strong uterine muscles with which to shape an egg. She therefore is more likely to lay eggs of normal shape than an unhealthy hen.

Age influences egg shape

The eggs of an older hen tend to be elongated. A pullet laying small eggs generally produces rounder eggs. Many bantam breeds, too, lay roundish eggs, but for those breeds, round is the normal shape.

Season exerts an influence on an egg’s shape. Eggs laid in the summer and fall are generally more elongated than those laid in winter and spring. Seasonal layers therefore produce more uniformly shaped eggs than hens that lay nearly year-round. 

What is a double yolker

Overly large eggs often have two yolks. Such double yolkers rarely hatch successfully. Even though the shell is larger than normal, it still lacks enough room to accommodate two embryos.

Assuming two embryos do begin to develop, one is apt to be considerably smaller than the other. And both, or at least the smaller one, may run out of growth space or oxygen and die in the shell. If both make it to hatching time, the cramped quarters will hamper the gymnastics required for them both to break into the airspace and eventually escape from the shell.

Despite all these obstacles, on rare occasions a pair of twins manages to hatch from a double-yolk egg. Typically, though, one or both will be physically abnormal and may not survive.

How to store hatching eggs

Once you collect the ideal egg for hatching, you don’t need to rush it into the incubator or under a setting hen. Saving up eggs is, in fact, a natural part of the incubation process.

In nature, eggs stay dormant while a hen accumulates a full setting before she starts to brood. That way the embryos can all develop at the same rate and hatch at the same time.

You can store eggs for up to 6 days without noticing a significant difference in the hatch rate. Keep them out of sunlight in a cool, relatively dry place such as a dry cellar, cool back room closet, or food storage pantry.

The ideal temperature is 55°F, but anywhere between 50 and 60°F is adequate. The ideal humidity is about 75 percent, with a range of 70 to 80 percent.

Happy hatching!

Gail Damerow has written many books about chickens. Those available at Tractor Supply include Hatching and Brooding Your Own Chicks, The Chicken Health Handbook, Storey’s Guide to Raising Chickens, and more. Visit Gail’s blog at gaildamerow.com.

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