From Calcium to Care: Key Factors Influencing Eggshell Quality in Layers

Eggshell quality is a crucial aspect of the poultry industry, particularly for layer hens that are bred for egg production. Poor eggshell quality can result in economic losses, as weaker eggs are more likely to break during handling, transportation, and storage, leading to reduced marketability and wastage.
Factors contributing to poor eggshell quality are multifaceted and range from environmental conditions to nutrition and genetic factors. This article delves into the primary causes of poor eggshell quality in layer hens, exploring each to offer insights into how poultry managers and farmers can mitigate these issues and improve production outcomes.
Nutritional Deficiencies
The most common cause of poor eggshell quality is nutritional imbalance, particularly deficiencies in key minerals and vitamins essential for shell formation.
Calcium Deficiency
Calcium is the primary mineral responsible for forming the eggshell, which is mainly composed of calcium carbonate.
A lack of adequate calcium in the diet results in thinner, weaker eggshells, as the body prioritizes calcium use for other vital functions, such as maintaining bone structure. Layer hens require around 3-4 grams of calcium per day, and failure to meet this requirement often leads to poor shell quality. Limestone or oyster shells are commonly used to supplement calcium in the diet.
During the growing period, a pullet’s calcium needs are pretty low. However, once she begins laying eggs, her calcium requirement surges to at least four times the previous amount, with nearly all of this increase going toward eggshell production.
Interestingly, a hen’s calcium requirement fluctuates throughout the day. Eggshell formation generally occurs around midnight, so if you notice thin shells, particularly common in older hens, consider supplementing their diet with calcium-rich oyster shell. Due to its larger particle size, oyster shell is absorbed slowly, allowing calcium to be available overnight when the shell forms. Additionally, it’s a good practice to switch to a laying feed about 10 days before hens begin laying, rather than waiting until eggs start forming.
Vitamin D Deficiency 
Vitamin D, particularly in its active form (D3), is crucial for calcium absorption and metabolism. Without sufficient vitamin D3, even with ample dietary calcium, the hen’s body cannot absorb and utilize calcium efficiently, leading to poor eggshell formation. A deficiency in vitamin D can thus indirectly cause shell quality ...