The Hoof

Understanding the factors that affect hoof health is one thing, but understanding how the dif­ferent parts of the hoof interact and why, or how, these factors affect hoof health is another. Understanding the structure of the hoof should help you realise the importance of good hoof health and how easily lameness problems can occur.

diagram2Abaxial view of a normal hoof

Source: Toussaint – Raven (2003)

The hooves are one of the most important parts of the cow’s body, as without these she cannot move around, exercise, feed, reproduce etc. The hoof grows very similarly to a human nail. Many factors can affect the growth process, such as diet, reproductive state or condition, genetics, living conditions, general wear and weight bearing forces.

This is evident in the rings that often occur on an animal’s hooves; due to variations in these factors, the horn is produced at different rates. The cow’s weight is distributed between all four hooves, with the front hooves usually bearing approximately 50-60 percent (it’s more equal in a young calf or heifer). When the cow is standing squarely and the claws are of even height and stability, the part of the body-weight borne by the hind legs should be evenly distributed over the two legs. The same should be true of the two fore legs.

diagram1

Biomechanics applied to the hind legs of cattle indicate that body weight borne by the hind legs should be evenly distributed over the two legs. (Toussiant Raven 2003) 

She should be able to walk and stand easily with proportional weight bearing or load. It is therefore important to keep all four feet healthy so that weight bearing does not alter and place extra pressure on one or more of the feet.,which can cause abnormal wear. The ideal hoof angle is around 45-50 degrees, and the claws should be slightly spaced.

diagram4

 

Weight bearing under normal conditions showing a healthy corium and germinal layer and strong, intact horny shoes. Man made conditions alter this and the claw often becomes overgrown resulting in unstable claws which tilt axially and backwards. Source:Toussiant-Raven (2003)

Along with diseases that can contribute to uneven horn growth or overloading of the claws and weight bearing on the heel bulb area, environmental hazards can also affect hoof wear and growth. If a cow is lame, it normally indicates a hoof disorder that has deteriorated to the point she experiences immense pain and consequently alters her gait or stance to cope. In this instance, speedy treatment of the animal is essential in order to ease her suffering and to prevent unnecessary culling or loss of production.

It could be said that if you have lame cows you have already lost the hoof health battle, but by regularly checking feet for any problems and acting at an early stage we should be able to prevent lameness. To a certain degree, this can be achieved by practicing preventative trim­ming – giving the hoof its protective and weight bearing shape back – and through general good management practices that keep the hoof clean, dry and in good condition. This is no easy task, of course, and many aspects of management need to be considered. But the point is that prevention is far better, easier to routinely manage and cheaper than treatment.

The hoof itself consists of two digits, the outer (or lateral) claw, and the inner (or medial) claw. The outer wall of the claw is called the abaxial surface and extends back to the bulb where it ends with a shallow indentation: the abaxial groove. The wall folds around the toe and the inner wall, or axial surface, joins the bulb to form a deep groove: the axial groove. The space between the claws, which separates the two heel bulbs, is called the interdigital cleft, and the skin is called the interdigital skin.

SKMBT_C28013112615451View of the hoof from underneath. Here you can clearly see how the outer and inner hoof wall is formed around the claws. Source Toussiant-Raven (2003)

On the hind feet, the lateral claw is usually slightly larger than the medial claw as it carries more weight and circumvents the udder during walking. The rear feet are used to push off, or for propulsion, whereas the front feet are used for flight response and to move to the side. Hence here, the medial claw is usually larger than the lateral claw. If cows are forced to move quickly, the claws are often put under greater pressure than normal, which can cause stress, structural damage or other injury to the foot. This can result in a lame cow if left untreated.

Described from the outside in, the hard hoof that encases the foot (which can be viewed like a shoe encasing our foot) is formed from one type of tissue, but the claws have two further tissue components underneath: the corium or quick, which contains all the nerves and blood vessels, and the pedal (coffin) bone, navicular bone and associated structures.

 Information kindly provided by DeLaval UK