Keratin is an extremely strong protein that is a major component in skin, hair, nails, hooves, horns, and teeth.
The amino acids that combine to form it have several unique properties, and depending on the levels of the various amino acids, it can be inflexible and hard, like hooves, or soft, as is the case with skin.
Keratins are rich in sulfur-containing amino acids, especially cysteine. Individual keratin molecules are entwined helically around each other in long filaments, which are cross-linked by bonds between sulfur atoms on different chains.
The entwining and cross-linking, produces strength and toughness within the hoof.
What does it do for the hoof?
The keratinous wall of the hoof transmits the forces passing between the ground and the bony skeleton of the horse.
To deal effectively with these forces, the wall tissue must be sufficiently rigid to prevent excessive deformation under the imposed load. At the same time, the material must not break. Rigid materials break because they fracture; cracks originating through stress.
The properties of keratin are strongly influenced by their hydration state.
This is why it is so important to oil your horses feet (all year round if necessary) to give them the best change of receiving quality nutrients to help continue healthy growth at the coronet band.
If when the keratin is being formed in the coronet band, there is an imbalance in the horses body through such circumstances like illness, stress, trauma, to name a few. It can be reflected in the formation stage and shows a deformation. Once the imbalance or trauma are normalised, the keratin formation continues and the wall starts to grow flat again.