Storey's Guide to Raising Chickens (71 page)

Be ready to inseminate hens right away, since fresh semen loses its fertilizing capacity after about an hour. Have the semen ready in the syringe or eyedropper. If you are inseminating more than one hen, use 0.1 cc for each.

Inseminate only a hen that has been laying; otherwise you run the risk of injuring her (and anyway, what would be the point?). Feel her abdomen to make sure a finished egg isn’t coming through to block the passageway. Hold the hen, and massage her the same way you did the cock. When you apply pressure on her abdomen, her vent will open up. You’ll see a fold of skin at the opening to the oviduct on the hen’s left (the opening on the right comes from the intestine).

Your helper should quickly insert the syringe 1 inch (2.5 cm) into the oviduct and inject the semen. As soon as the semen is injected, release your pressure on the hen’s abdomen to let the vent close and draw in the semen.

You should start getting fertile eggs 2 to 3 days after the first insemination. Early in the season inseminate hens at least every 7 days, preferably every 5 days to ensure good fertility. As the season progresses and fertility drops, inseminate more often.

Insert the semen in the left opening, which leads to the oviduct (the opening on the right goes to the intestine).

All the genetic information that’s transmitted from a chicken to its offspring is organized on chromosomes. A cock has 39 pairs of chromosomes. One pair, called the sex chromosomes, contain the information that determines gender. The other 38 pairs are called autosomal chromosomes. Like a cock, a hen has 38 pairs of autosomals, but unlike a cock, she essentially has only one sex chromosome.

Every fertilized egg contains a sex chromosome from the cock, but a hen transmits her sex chromosome to only about 50 percent of the eggs she lays. If a fertilized egg contains sex chromosomes from both the cock and the hen, it will hatch into a cockerel; if it contains only the single sex chromosome contributed by the cock, it will hatch into a pullet.

Since each egg has a 50/50 chance of containing two sex chromosomes, eggs hatch in approximately a 50/50 ratio of cockerels to pullets. The two most common reasons for significant deviations from this ratio are:

Random death of embryos and chicks

Sex-linked lethal genes

Despite all sorts of old wives’ tales to the contrary, determining in advance which sex will hatch from a given egg is not a simple matter; if it were, the poultry industry would be using the technique. After a chick hatches, the traditional way to learn its sex is by the Japanese method, also known as cloacal sexing or vent sexing. Accuracy depends on the skill of a trained observer in examining minor differences in the tiny cloaca just inside a chick’s vent.

Because a pullet does not acquire her dam’s sex chromosome, she cannot acquire any of the genetic information it contains. A cockerel, on the other hand, always acquires genetic information contained on its dam’s sex chromosome. All characteristics that are controlled by genes on the hen’s sex chromosome are called
sex linked
. Some sex-linked characteristics are the silver color pattern (white plumage with black hackles, wings, and tail feathers), albinism, dwarfism, nakedness, barring, late feathering, and broodiness.

When a hen with a certain sex-linked trait is mated to a cock without it, the trait is acquired by all the resulting cockerels but not the pullets. Since all the pullets are like their sire and all the cockerels are like their dam, this so-called
crisscross inheritance
allows the sex-linked sorting of chicks according to such things as their color or the speed of their feather growth.

Color sexing takes advantage of the sex-linked gene that controls feather color. It is commonly used to produce hybrid brown-egg layers. Numerous variations are possible.

When you mate a barred Plymouth Rock hen with a Rhode Island Red rooster, all the chicks will be black, but each cockerel (right) will have a white spot on its head.

Mating a white Rock or white Leghorn hen with a Rhode Island Red or New Hampshire cock, for example, results in white cockerels and red pullets. Examples are Red Star and Golden Comet. Crossing a barred Rock hen with a Rhode Island Red or New Hampshire cock will give you black chicks, but each cockerel has a white spot on its head. Examples are Black Sex Link and Black Star.

Feather sexing involves crossing a slow-feathering hen (such as a Rhode Island Red) with a rapid-feathering cock (such as a white Leghorn) to get slow-feathering cockerels and rapid-feathering pullets. The chicks may be sexed with fair accuracy by the appearance of well-developed flight feathers on the wings of pullets at the time of hatch. Feather sexing is commonly used in the broiler industry, where only white-feathered birds are preferred, to separate slow-growing pullets from their faster-growing brothers.

BETWEEN THE FUN OF MAINTAINING
a breeder flock and the joy of raising your own chicks comes a 21-day period of anticipation while you wait for the chicks to hatch. Even old pros sometimes have pangs of anxiety during this waiting period, as they know, and have probably experienced, all the things that can go wrong. But you can look forward to the enormously rewarding experience of hatching your own chicks by paying careful attention to detail, starting with when and how you collect eggs destined for hatching.

A breeder flock is strongest and healthiest in spring, making spring chicks the strongest and healthiest as well. Chicks hatched in cool weather also have time to develop immunities before encountering germs that proliferate in the warm, humid weather of summer; chicks hatched later in the year don’t have that luxury.

Pullets hatched in spring begin laying by fall and continue to lay for about a year. Pullets hatched in winter will begin laying by midsummer but may molt and stop laying in the fall and won’t start again until the following spring.

Large breeds mature in 8 to 10 months, bantams in 6 to 7 months. If you raise show stock and want to have young birds in prime condition for the fall round of shows, hatch large breeds no later than December and bantams no later than March.

For general health and vigor, in most areas the best months to collect eggs for hatching are February and March. In the far north, where the weather stays cold long into spring, March and April are the best hatching months. Collect eggs at least three times a day to minimize their contact with dirty surfaces and to keep them from getting chilled or overheated, thus reducing their hatchability.

An egg need not be rushed into the incubator the moment it is laid. Saving up eggs is, in fact, a natural part of the incubation process. In nature just-laid eggs go dormant to give a hen time to accumulate a full setting before she starts to brood.

Even under optimum storage conditions, the longer eggs are stored, the longer they will take to hatch. Also their ability to hatch decreases with time. You can store eggs for up to 6 days without noticing a significant difference. For each day thereafter, hatchability will suffer by approximately 1 percent. I don’t feel comfortable storing eggs for hatching for longer than 10 days.

When a hen selects a place to make her nest, she instinctively seeks out conditions that are optimum for storage and incubation. When you gather and store eggs for hatching, try to duplicate those conditions.

Store eggs out of sunlight in a cool, relatively dry place but not in the refrigerator. The best temperature is 55°F (13°C). Humidity should be low enough to prevent moisture from condensing on the shells, which would attract molds and also encourage any bacteria already on the shell to multiply.

Excessive dryness, on the other hand, increases the rate at which moisture evaporates through the shells. The less moisture that evaporates from eggs during storage, the better chance they have of hatching. Small eggs laid by bantams and jungle fowl have a relatively large surface-to-volume ratio and therefore evaporate more quickly than larger eggs. Late-summer eggs of any size have thinner shells because the hen has been calling on her calcium reserves all summer. These shells allow more rapid evaporation than occurs in early-season eggs. To minimize evaporation of eggs stored longer than 6 days, seal cartons in plastic bags, or better yet, wrap the eggs individually in plastic wrap.

Store eggs in clean cartons. Hard-plastic egg cartons (of the sort backpackers use) can be easily disinfected for reuse; recycled Styrofoam or cardboard cartons from the grocery store accumulate bacteria over time. When I use such cartons for hatching eggs, I discard them after one use.

Place eggs in the carton with their large ends up to keep the yolks centered within the whites. If the eggs will be stored longer than 6 days, keep yolks from sticking to the inside of the shell by tilting the eggs from one side to the other. Instead of handling eggs individually, elevate one end of the carton one day, and the opposite end the next day.

Select eggs for hatching that are of normal color, shape, and size for your breed. Small eggs laid by pullets or old hens will give you smaller, less vigorous chicks. Excessively large eggs 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. Eliminate eggs that are round, oblong, or otherwise oddly shaped and those with shells that are wrinkled, glassy, or abnormal in any other way.