Marine shell grit

Marine shell grit is a natural and useful source of calcium for poultry. The calcium is completely, but gradually, absorbed into the bloodstream. This ensures a higher and more continuous calcium level, also during eggshell formation. Adding marine shell grit to the feed, especially for older hens, has an immediate result.

A hen’s calcium needs are enormous throughout her productive life. The amount of calcium in an eggshell is so high that the hen needs to be able to absorb high levels of calcium in a short period. The efficiency and speed that older hens do this in declines. This is why older birds have problems with their calcium levels, reducing their eggshell quality. Marine shell grit is a useful source of calcium that helps to prevent this problem.


Using marine shell grit for hens is a long-standing tradition. However, marine shell grit can also be used in the broiler sector. Marine shell grit has a positive effect on the development of a strong bone structure. Furthermore, the coarse grit ensures the improved grinding of the feed. This leads to less feed dysfunctions.

Influence on feed conversion

Marine shell grit has a coarse structure. This allows the bird’s selective uptake of what it needs. Studies have shown that this has a positive effect on feed conversion; grit prevents overfeeding.

Natural origin

Marine shell grit is a natural product from the sea. Besides calcium, it contains other minerals and metals. We produce the marine shell grit under strict conditions. The products are washed, dried at high temperatures and then sieved.


  • Marine shell grit 1             1-2.5 mm

This is suitable for small birds, chickens, quails and pheasants. It is also highly suitable as a raw material for various bird grits for ornamental birds.

  • Marine shell grit 3            2-5 mm

This is suitable for young to adult hens. This size also works well in most automated feed systems.

  • Marine shell grit 4            4-7 mm

The coarser grit is suitable for adult hens, turkeys and ostriches.

More information
We are happy to provide you with more information. Please contact Van der Endt-Louwerse, email:  or phone +31 (0)113 571582.