As an Extension Agent with a background in poultry, I receive many poultry questions concerning anatomy, biology, egg production, etc. The information below answers some of the most common questions received.
What is the average lifespan of a chicken?
Chickens can live for several years if their living conditions are correct. it is not uncommon for a chicken to live 6 to 10 years. However, most commercial laying hens are kept 2 to 3 years.
How old are chickens when they begin to lay eggs?
Under ideal conditions (correct nutrition, correct day length, proper housing & management), hens begin to lay eggs at around 20 weeks of age. There may be some hens that start a little earlier or a little later than the average.
My hen just hatched some chicks. What is the male/female distribution? How can I tell if the chicks are male or female?
Under normal conditions, a random mating results in a 50:50 ratio of male to female offspring. Determining the sex of newly hatched chicks is very difficult. Some cross-breeds result in differences in feather length of male and female chicks. However, these are accomplished under controlled conditions. In most cases you will have to wait until the chicks are older to determine the sex.
Why have my hens stopped laying eggs?
Hens stop laying eggs for one of 3 reasons:
- Disease has caused the hen to dramatically decrease or stop egg production,
- The hen has been in production for a long time and she is beginning to enter a molt, or
- The hen is not properly stimulated by light (hens require a certain amount of light during the waking hours for egg production).
Incubation, Embryology, & Eggs
Which part of the egg develops into the baby chick – the yolk or the white?
Actually, neither the yolk nor the white develop into the baby chick. A group of cells on top of the yolk, called the germinal disk, will develop into a baby chick, if conditions are right. in an unfertilized egg, the cells look like a small, pale dot. In a fertilized egg that has been incubated for a few hours, the disk is doughnut shaped. The egg white, or albumen, contains many antibacterial elements that help protect the developing embryo. The yolk is the nutrient source.
Will a double-yolked egg develop into twin chicks?
The short answer is no. While both germinal disks may start to develop after fertilization and the beginning of incubation, there is not enough room inside the shell to support the development of two chicks. Fertilized double-yolked eggs almost never hatch out; and if they do, only one chick will have developed.
I’ve heard that a small change in incubation temperature will influence the sex of the hatching baby chicks. Is this true?
The incubation temperature has no influence on the sex of the chick that hatches. In chickens, the chromosomes that determine sex are ZZ for male and ZO for female (compared to XX for female and XY for male in humans). The combination of the chromosomes is what determines the sex of the chick. Manipulating the incubation temperature will most likely result in fewer eggs hatching overall, but it will not change the sex of the chicks that do hatch.
In chickens, it is the female that determines the sex of the baby chick. This is exactly opposite of humans, where the male determines the sex of the offspring.
Which is better for you nutritionally, a brown-shelled egg or a white-shelled egg?
Egg shell color does not determine the nutritional properties of the egg. This is also true for fertilized vs. non-fertilized eggs. Hens that are fed a similar diet produce eggs with a similar nutrition profile no matter the color of the shell of if the egg is fertile. It is possible to slightly manipulate some of the nutritional properties of the egg by changing the diet of the hens, but this has to be done carefully. Simply put, an egg is an egg, insofar as the nutritional properties are concerned.
How can I tell what color eggs my hen will lay?
The breed of chicken determines the color of egg that she will lay. You can consult a breed handbook and that will give you that information. However, there is an easier way to determine what color of eggs your hen will lay. For the majority of hens (not all), the color of the earlobes will indicate the color of eggs. Hens with white earlobes lay white-shelled eggs, while hens with red earlobes lay brown-shelled eggs. Of course, there are exceptions to the rule, like the Araucana and Ameraucana, which lay eggs with a green-blue tint to the shell.
Poultry Meat and Egg Products
What causes blood spots in eggs? Are these eggs safe to eat?
Finding an egg with a blood spot is rare in commercially produced eggs (these eggs are usually taken out of the production line and discarded). However, you may find eggs with blood spots or meat spots from your backyard flock.
Blood spots are caused by the rupture of a blood vessel that carries materials to the yolk as it develops within the hen. As the yolk is deposited into the reproductive tract, the vessel ruptures and leaves a blood spot on the yolk. Blood spots do not indicate that an egg is fertile. These eggs are safe to eat. The blood spot can be removed with the tine of a fork or the tip of a knife.
Meat spots can also be found in eggs, although they are typically found in the albumen, or white, of the egg instead of on the yolk. A meat spot is a small piece of the hen’s reproductive tract that has sloughed off during egg formation. Eggs with meat spots are also safe to eat. The meat spot can be removed in the same manner as a blood spot.
I’ve heard that eggs from Aracauna chickens have no cholesterol. Is this true?
This is not true. Eggs from Aracauna chickens contain cholesterol in approximately the same amount as other chicken eggs.
Why do poultry have light and dark meat?
Like other animals, muscles in poultry perform different tasks depending on their location. This also means that muscles are used at varying rates. Muscles that are used a lot and over long periods of time require a lot of oxygen to perform well. There is a compound in these muscles called myoglobin. Myoglobin stores oxygen for use by the muscle and is very similar to hemoglobin, which is found in the blood. When myoglobin has oxygen stored for use it has a red color. Muscles that are used extensively contain a lot of myoglobin, thus resulting in the reddish, darker color. Muscles that are used less or for only short periods of time contain much less myoglobin and will appear lighter in color. This is why domestic chickens and turkeys have dark meat in the legs and thighs (muscles which get used a lot) and light meat in the breast and wing (muscles that only get used for short periods of time). In fowl that fly, such as wild ducks, there will be dark meat in the breast area as well as the legs and thighs.
Are hormones used to produce commercial poultry meat?
No. Hormones are not fed to or administered to commercial poultry. Federal law prohibits the use of hormones in poultry meat and egg production. The rapid growth rates, high egg production, and feed efficiencies seen in poultry today are the result of selective breeding, excellent nutrition, and good husbandry practices. Please note that poultry product labels cannot contain claims such as “No Hormones Added” unless it is followed by a statement that says “Federal regulations prohibit the use of hormones…” as this practice is against federal law.
Why do some chickens in grocery stores have yellow skin while others have white skin? Related…Why do some eggs have a darker yellow yolk than others?
The yellow color of the skin and the deeper yellow color of yolks comes from the ingestion of yellow and orange pigments. These pigments are found naturally in some of the ingredients that make up the poultry diet, such as corn. Grasses and other plants also contain these pigments. The pigments are absorbed from the feed and produce the yellow color in the skin and in the yolk. Another common pigment ingredient found in some poultry feeds is marigold extract. It is used for pigmentation purposes only. There is no nutritional difference in poultry meat or eggs derived from the difference in pigmentation.
How long will table eggs stay fresh?
Fresh eggs can be stored in refrigerated temperatures (40°F to 45°F) for 4 to 5 weeks after the packaging date on the carton. Hard-boiled eggs should be refrigerated and should not be kept for more than 1 week after cooking.
Salmonellosis is more common in the summer than in the winter. There are more than 2,500 serotypes of Salmonella known. For more information, click here.
How long can I keep fresh poultry meat? What about frozen poultry meat?
All fresh meats, including poultry, should be consumed or frozen within one to two days after purchase. Poultry meats that are frozen will retain their quality for 3 to 6 months in the freezer.