animal health
Eggshell Quality: What is a good eggshell?
The eggshell is a vital barrier to keep the egg safe from outside effects and a membrane that helps eggs exchange gas and humidity. Lots of things about laying hens has changed dramatically such as genetics, diets, design of the buildings, etc. There is only one fact that has never changed: “The eggshell needs to be as strong as possible to maximize the number of eggs reaching the market”. Good eggshell formation requires critical macro minerals and essential trace minerals supplied in the feed.
Eggshell Quality: What is a good eggshell?
Most of the good-quality eggshells from commercial layers share the following properties:
- Around 95 % of dry eggshells consist of calcium carbonate which is around 5.5 grams and contains approximately 2.2 grams of calcium.
- About 0.3 % phosphorus and 0.3 % magnesium and traces of sodium, potassium, zinc, manganese, iron, and copper.
Under the eggshell, there is an organic matrix material that has calcium-binding properties and it influences the strength of the shell.
It´s a lot of calcium, right?
A layer needs 20 times the calcium contained in its bones to produce about 250 eggs per year. Thus, the calcium need of the laying hen is high. During the period of egg development inside the hen’s body, 25 mg of calcium is deposited every 15 min.
Is that enough for a hen to take all calcium from the feed?
Of course, a laying hen is not fully efficient in absorbing calcium from the diet. Hence, the diet has to provide more than 4 grams of calcium to the hen daily. The calcium amount in the feed is sometimes not known and, in such cases, it is recommended to give an extra calcium source to provide the necessary amount of calcium.
It gets even worse in the later stages of production
During the late stages, flock performance decrease, and eggshells become larger and thinner. Another reason is absorbing calcium in feed becomes less efficient than it is in younger hens. As a result, thinner, soft, and cracked eggshells can be seen more often. Due to this challenge, farmers have to replace the flock earlier which causes them financial losses, reduces their profit and also has a bad impact on environmental sustainability.
It gets even worse in the later stages of production
During the late stages, flock performance decrease, and eggshells become larger and thinner. Another reason is absorbing calcium in feed becomes less efficient than it is in younger hens. As a result, thinner, soft, and cracked eggshells can be seen more often. Due to this challenge, farmers have to replace the flock earlier which causes them financial losses, reduces their profit and also has a bad impact on environmental sustainability.
So, what can we do?
One of the most important factors is nutrition. Providing a good source of calcium, phosphorus, and Vitamin D3 will give a much better chance to produce thicker eggshells. Studies have shown that supplementing older birds with more calcium results in supporting eggshell integrity and reducing the number of cracked eggs.
In addition, our Science on the Field team has shown that our products, such as Cal D Phos and Ovostrong, increase the quality of eggshells and total egg production – As a result, increased overall profitability.
Please see the links to the trials below:
Sources:
| R. M. G. Hamilton, W. L. Bryden. (2021) Relationship between eggshell breakage and laying hen housing systems – an overview. World’s Poultry Science Journal 77:2, pages 249-266. |
| Butcher, Gary D., and Richard Miles. “Concepts of eggshell quality.” VM01300. PDF 6 (1990). |
| Solomon, Sally E. Egg & eggshell quality. Iowa State University Press, 1997. |
| Ketta, M., and E. Tůmová. “Eggshell structure, measurements, and quality-affecting factors in laying hens: a review.” Czech Journal of Animal Science 61.7 (2016): 299-309. |
