Learn more about egg yolks
What is egg yolk?
The general idea of the word living cell takes our minds to the microscopic world. But it is better to know that egg yolk has been in front of human eyes for thousands of years. The yolk is actually a single cell that is visible to the naked eye. An adult egg or yolk reaches a diameter of about 4 cm in a week.
What is the role of yolk?
The role of the yolk in the egg is to provide nutrients to the developing fetus. During the formation of an egg in the body of poultry, the first yolk develops in the ovary. The yolk then enters the oviduct and subsequently white layers and crust are formed on it. The composition of the yolk remains constant from the time it leaves the ovary. The yolk is rich in beneficial fatty acids, proteins, vitamins and minerals needed for fetal growth. The chicks are still digesting the remaining yolk in their yolk sac after hatching. Managing the chicks when absorbing the yolk sac is very important.
During fertilization, when the reproductive ring turns into a chick, the yolk is used as food for the fetus. The yolk floats inside the egg slightly above the middle of the reproductive ring to be closer to the mother’s body temperature. The hen constantly moves her eggs to prevent the yolk from sticking to the shell.
When you boil a raw egg, the egg white, which contains albumin, hardens and directs the yolk to the middle of the egg. The weight of the yolk is usually about one-third of the total egg, but in eggs with white shells this amount is higher than in brown shells.
Yolk quality
The quality of the yolk indicates better health and better nutrition of the bird. The yolk acidity at the beginning of egg production is about 6, which increases to 6.4 to 6.9 over time. When the pH of the yolk increases, it is observed that the yolk is mixed with the white. This is due to the rupture of the vitelline membrane. The presence of anticoccidial drugs can also permeate the yolk membrane, resulting in white spots inside.
The more energetic the diet and the more suitable the amino acids lysine in it, the larger the yolk. The larger yolk equals the larger egg resulting in better product marketing. Unsaturated fatty acids, especially linoleic acid, will increase the amount of yolk.
This is why whole processed soybeans or meal, along with the right combination of beneficial unsaturated fatty acids, increase the weight of the eggs produced. There is also a direct relationship between dietary energy and egg weight.
The color of the yolk has little to do with how nutritious the egg yolk is. This generally depends on the type of chicken and the amount of pigment present in the feed.
Adding some foods such as yellow corn, alfalfa, dried vegetables, etc. makes the yolk more orange and more grains in the diet make it more yellow.
However, a change in yolk color in a laying flock can indicate selective feed intake, digestive disorders, disease, or the presence of some undesirable substances in the feed. The yolk turns green due to the consumption of cottonseed oil and its whitening is due to the presence of hair cream parasites in the intestine.
You can find interesting points by boiling eggs and cutting the yolk diagonally. If the eggs are layered with different colors, it can be concluded that there were intermittent nutrient deficiencies or food heterogeneity in the days when the yolk was formed.
The larger yolk equals the larger egg resulting in better product marketing.
A fertilized egg with a blood stain or a piece of meat
A fertilized egg is seen when a chicken and a rooster are together. In the case of industrial egg production, the only factor that causes the presence of sperm in the eggs is a mistake in determining the sex of the laying hens, in which case the rooster may enter a group of laying hens.
If the egg is fertile, the reproductive ring begins to grow, and if the temperature is close to room temperature, blood stains form in it. However, the presence of blood stains can be due to disease or environmental stress.
Pieces of meat are sometimes seen in the yolk, which may be pieces separated from the surface of the oviduct that have entered the egg with the yolk. Shalazza, which is a longitudinal thread inside the egg, can also sometimes be confused with sperm.
