By Carol Layton – Balanced Equine
There are many factors that influence the type of hoof a horse will have; these include
- type of environment,
- amount of movement,
- quality of hoof care, especially in the early years of a horse’s development
- and nutrition.
No one factor on its own can produce the best possible hoof if one or more of the others are working against it. Nutrition alone can’t do it, nor can hoof care on its own.
Studies specifically looking at nutrition and hooves have shown that certain nutrients can affect rate of hoof growth, how hard and tough the hooves can be, how strong the cellular connections in the wall, sole and frog are, the thickness of the wall, prevalence of seedy toe (white line disease) and laminitis.
Any weaknesses in the horn can lead to microscopic openings for microbes to gain entry to cause infections, to large cracks and chips.
Deficiencies in protein including specific amino acids for keratin production, essential fatty acids (omega-3 and omega-6), selenium, vitamin E, biotin and copper and zinc will negatively impact on hoof growth and quality.
Fortunately, on a high forage diet, vitamins like biotin are far less likely to be deficient. If biotin is not deficient, the amount supplemented will be excreted.
The hoof wall is about 93% protein on a dry matter basis; protein is the structural component of all organ systems. Amino acids are the building blocks of protein, some like lysine and leucine are known as ‘essential’ which means that they have to come from the diet and others like alanine and glutamine are ‘non-essential’, they can be manufactured by the horse.
The key proteins in the hoof are keratins, mainly an alpha-keratin which gets its strength from the cross linking of the amino acids alanine and glycine and the sulphur containing amino acid cysteine, manufactured from methionine. The more cysteine; the harder the hoof horn.
Cells that contain keratin arrange themselves in long tubules which, in turn, arrange themselves in a spiral that acts like a spring. The tubules deform, and then bounce back when the horse bears weight on each foot, providing a natural cushioning effect.
The chemical structure of keratin differs depending on whether it makes up soft tissues like skin and hair to the very strong and tough tubules of the hoof wall. In the hoof wall, the process of keratinisation makes the fibres insoluble in water and more resistant to chemical and physical attacks. In comparison the frog and white line are slightly different chemically, resulting in greater elasticity but lower physical strength.
Much has been written about the importance of zinc in the hoof and justifiably so. Zinc is present in high concentrations in the hoof with one form being the zinc finger proteins, rich in the amino acid cysteine. As part of the zinc finger proteins, zinc is needed for cell multiplication and the assembly of keratin. Zinc proteins incorporated into keratin are also responsible for the helical structure that gives hooves their strength. One study showed that horses with insufficient hoof horn strength had less zinc in the hoof horn and plasma than did horses with no hoof horn damage.
Many enzymes that are responsible for a multitude of cellular processes require zinc, such as binding calcium in keratin. In people, nearly 100 different enzymes depend on zinc for their ability to catalyse vital chemical reactions.
Copper doesn’t get the same attention as zinc in the hoof but the synthesis of the harder type of keratin is linked with copper as well as formation of connective tissue. In horses, one study found a deficiency in both zinc and copper increased the incidence of seedy toe in performance horses.
In cattle, a copper deficiency is known to be a cause of poor hoof condition, greater incidence of foot rot, heel cracks and sole abscesses.
The basic nutritional management for horses should be the same, whether you have a much loved member of the family in the back paddock or are feeding a horse to comfortably complete a trail ride or a high level performance event.
The foundation of any diet should be high fermentable fibre forage; pasture and/or hay. The ultimate goal in feeding should be to have a healthy horse able to perform at the best of their ability at their level of fitness and conditioning with a well-supported and robust immune system.
All horses, regardless of the level of work or whether they are breeding will benefit from a diet with sufficient nutrients and balanced minerals.