Most eggs are oval. This is natural and eggs laid by the same hen tend to be of the same size and shape.
A standard egg weighs 56.7grams with a volume of 63cms cubed, a long circumference of 15.7cm and short circumference of 13.7cm.
Abnormalities in shape are many and may include flat-sided, elongated, ball–shaped, wrinkled, shell-less, thin shells and rough shells.
Some of the abnormalities are due to genetics, diseases, poor feeding or harsh environmental temperatures. Others are probably due to abnormalities in the oviduct, such that the eggshell is not uniformly formed.
Egg size varies from bird to bird. Young birds lay small eggs. If hens are not getting enough water or protein in their feeds, or because of hot weather eggs laid may be of reduced size or thin shelled.
Diseases such as Newcastle disease, infectious bronchitis and use of some drugs have been known to cause the laying of eggs with rough shells.
You can make nests for your hens. Various materials are used for making nests for the chicken to lay from. These include dry grass, dry banana leaves, cotton, sand, old clothes, unthreshed millet and other cereals under storage.
The nest materials should be clean and be able to retain warmth. These materials can be put in excavations, cut jerrycans, boxes, baskets, broke pots and other related materials.
Nests should be shallow in order to allow all eggs in there to have direct contact with the hens body from which they get warmth, moisture and turning.
These are the three essential factors to successful incubation. Nests may be located on or above the ground. In some communities in Uganda nests may be located inside granaries, under granaries, hang on verandahs or even in the main house.
The choice of location is dependent on the cultural practice and security. A good nest is necessary for better hatchability. The nests should be dry and protect eggs from breakage and should provide the chicken with warmth.
They should also be located in places that are cool enough with fresh air. During the incubation period, hens will often leave their nests to look for food. However, these visits will decrease as the days progress.
These visits have however got an effect on the hatchability because when the hen is away, the eggs cool down which interferes with the chick’s development inside the egg.
This is why it is recommended that food and water should be put near the nests so that the hen does not move too far away.