Science News 03/01/2011

Maintaining proper hoof health

Environmental conditions during the spring and fall seasons often predispose animals to hoof problems

Maintaining proper hoof health continues to be one of the biggest challenges facing beef and dairy producers. Environmental conditions during the spring and fall seasons often predispose animals to hoof problems which can range from hoof cracks to foot rot. In severe cases, these issues can lead to decreased rates of gain or breeding difficulties. The following outlines some of the problems associated with hoof health as well as some methods to prevent this issue.

Hoof health problems can generally be traced back to one or a combination of the following four factors: 1) genetics; 2) environment; 3) disease; and 4) nutrition.

Genetic contributions to hoof health problems can be sorted out relatively easily. Pay attention to which animals have hoof problems and if animals from a certain sire or dam continually have problems, cull that sire or dam as well as their offspring.

The environment is not as easy to control. The hooves of animals that have to stand in wet, muddy conditions eventually soften which makes injury more probable. In addition, animals that are maintained on very hard surfaces are also prone to hoof injury. Allowing animals access to soft, dry areas can help alleviate these types of hoof problems.

The primary disease affecting the hoof is foot rot. Foot rot is caused by the bacteria Fusobacterium necrophorum. Animals diagnosed with foot rot should be separated from the rest of the herd as they will shed the bacteria and any other animal that injures its hoof will be more susceptible to infection. There are a number of antibiotics available for the treatment of foot rot as well as some vaccines that may help prevent foot rot.

Nutritional causes of foot rot are some of the hardest to diagnose but may be the easiest to treat. There are a number of nutritional factors that affect hoof quality. These nutrients include: amino acids, vitamins, fatty acids, and a number of minerals. Of the minerals involved, zinc (Zn), copper (Cu), and manganese (Mn) are particularly vital to hoof health. Both Zn and Cu are necessary for the formation of keratin, the hard outer surface of the hoof. Deficiencies of either of these two trace minerals results in a softening of the hoof wall which can lead to cracks, foot rot, and sole abscesses. Manganese has a less direct role and mainly helps minimize hoof problems by maintaining proper leg formation. In addition to these roles, each of these three trace minerals is involved in proper immune function. Zn, Cu, and Mn all play a role in the antioxidant enzyme superoxide dismutase which helps to rid the body of cell damaging free radicals. Zinc is also directly involved in wound healing and antibody formation.

Nutritional causes of hoof problems are usually the result of a mineral deficiency. In many areas the Zn and/or Cu concentration in the forage is inadequate to meet the animal’s needs. The Mn concentration of most grasses is often sufficient; however, it may not always be in a form that the animal can use. Furthermore, the feed, water, and soil that the animal consumes may contain mineral antagonists. These antagonists can bind to the mineral in the feed or digestive tract thereby making the mineral unavailable for absorption and use by the animal. For these reasons, it is advisable to supply some form of trace mineral supplementation to cattle.

Inorganic trace mineral sources (mineral sulfates, oxides, or chlorides) may be sufficient to prevent deficiencies but these will often be of little use when antagonists are present. When antagonists are present or when the level of antagonism is unknown it is usually best to use an organic trace mineral source (mineral complexes or chelates). Organic trace minerals are protected and thus not prone to binding with antagonists in the diet. Figure 1 shows the effect of Zn source on hoof scores in growing bulls. Figure 1. The graph below shows the effect of trace mineral source on hoof score.

Lower score indicates better hoof quality
In this research, the organic Zn sources either maintained (Zn proteinate) or improved (SQM Zn) hoof score of the bulls while those either supplemented with Zn oxide or not supplemented at all had worsening hoof scores over the 284 day trial, indicating a zinc deficiency. Figure 2 shows the visual improvement in hoof quality of one of the bulls in the SQM Zn treatment from day 1 to day 284. Figure 2. The effect of SQM Zn supplementation on hoof health at the beginning (top) and end (bottom) of a 284 day study.

Hoof health problems are a hurdle that beef and dairy producers are going to continue to face for the foreseeable future. Good management practices and proper nutrition can help to alleviate these problems, but may not be enough to eliminate the problem entirely.

di S. C.