How to make gaffs for roosters

How do chickens fertilize eggs?

Science 2021

Chickens, like other birds, lay fertilized eggs through external reproduction. Depending on the number of chickens, a hen starts laying eggs between five and seven months of age.


Like other birds, chickens lay fertilized eggs through sexual reproduction. Depending on the breed of chicken, a hen starts laying eggs between five and seven months of age. The frequency of oviposition varies depending on the breed, season, moult and age. However, most of the breeds used for egg production lay an egg every day or two.

TL; DR (too long; not read)

Chickens reproduce through sexual reproduction: a rooster mates with a hen, which then lays a fertilized egg.

When are eggs fertile?

An egg will only produce a chick if the hen has mated with a rooster before the egg has formed. Most production-oriented farms do not have a rooster to whirl around unless it is time to produce a new batch of laying hens. This means that almost all eggs in the supermarket are unfertilized.

Roosters are more common in small flocks or hobby flocks. For farm fresh eggs from a smaller flock, almost any egg is likely to be potentially fertile. But don't worry: the embryo is usually just a yolk mark and stops growing when the egg is refrigerated. Fertilized eggs require twenty-one days of incubation at a specific temperature (the temperature that would be below a mother hen) to produce chicks.

Chickens breed outdoors when the spring days get long. While the rooster mates with its chickens year-round, they usually only incubate eggs when conditions are optimal. A hen who decides to incubate eggs is said to have "gone broody".

The rooster does its part

Roosters have reproductive organs, much like mammals, with testes that produce sperm. The sperm migrate to the semen sacs in tubes called vas deferens. During mating - a not-too-dangerous proposition that lasts less than 20 seconds - the sperm leave the male through an opening called a cloaca and enter the female through an entrance to her reproductive tract, the fallopian tube. From there, the sperm migrate through the reproductive organs of the female. On a journey that can take a week or more, they swim through the chicken shell gland, then a narrowing in their reproductive tract called the isthmus, followed by the magnum and infundibulum. There they wait for the arrival of eggs that are just forming.

The hen does hers too

Chicken eggs start out as yolks in the ovary, and once they are released they enter the infundibulum, a funnel-shaped organ where the sperm wait. There they are fertilized and leave the chicken the same way the sperm entered. The egg white collects around the yolk in the magnum. The shell membranes are deposited in the isthmus. The shell forms and hardens in the shell gland, and the egg can be laid. Most chickens do not lay eggs in the evening. So when a hen's egg is ready it will likely be kept until morning. As soon as it is in place, it is ready to form a new egg. After mating, enough sperm may remain in the hen to fertilize her eggs for a week or more.

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