It is common knowledge that hoof health and lameness in dairy cattle is a significant problem for the producer and the dairy industry in general. Research from 2009 reported that as many as 52 percent of all dairy cattle in any given herd may experience some degree of lameness in any given year (with an average of 20 to 25 percent of cows per farm).

Economic data clearly points out that the results of foot and hoof insult are much greater than the treatment costs alone.

Associated costs and depressed revenues result from a decrease in milk production and breeding rates as well as increased culling and discarded milk.

To this is added the increased labor costs to manage affected cows as well as the need to grow more replacement heifers or purchase replacement cows. All of which are circumstances that add pressure to an already marginalized bottom line.

Current research shows that treating an average case of lameness will cost the dairyman $300. At the rates shown above (25 percent) this can translate, on the bottom side, to $7,500 per 100 cows per year.

Most producers also understand that lameness is associated with various disease conditions and can have multiple causes. One of the most important is laminitis, which is associated with sole ulcers, white-line separation and heel horn deterioration.

It is an inflammation of the sensitive tissues (lamellae) of the hoof and is associated with both nutritional and management problems.

Several infections of the hoof infections, such as inter-digital dermatitis, digital dermatitis (hairy heel warts, strawberry heel) and foot rot are generally related to environmental conditions and the presence of causative bacteria.

These diseases generally affect the skin and soft tissues of the hoof rather than the claw itself. Control of these diseases is accomplished mostly through management and aggressive therapy, but nutrition impacts skin and hoof horn integrity, which together make up the first defense.

Hoof problems and lameness are caused by a variety of factors including housing and environment, management, genetics and various diseases.

Perhaps the most significant collective contributors to predispose a dairy cow to hoof and claw problems are feeding and nutrition.

Proper nutritional management can significantly lower the number of foot problems in the dairy herd. Laminitis has many contributing factors, but a properly designed and managed feeding program will go a long way toward prevention.

Numerous components of nutrition management play a role in hoof health, ranging from major ration components such as protein and fiber down to vitamins such as biotin.

A considerable body of evidence exists on the effects of protein, carbohydrates, non-forage fiber sources and length of fiber particles, as well as other macronutritional factors on hoof epidermis and hoof horn quality.

Considerable attention has been given, in recent history, to smaller nutritional components such as macrominerals, trace minerals and vitamins.

Laminitis and rumen function
Laminitis in dairy cattle has been associated with rumen function and production of excessive organic acids in the rumen. Incidence of laminitis also reflects improper ration formulation or feeding management.

One product of normal carbohydrate fermentation in the rumen is organic acids, such as acetic, propionic and lactic acids, as well as a variety of others.

These acids are necessary to the animal as they are precursors to glucose synthesis (energy) and fatty acids (butterfat) production.

Highly digestible carbohydrates (starches) produce large amounts of acid, particularly lactic acid, which can be a problem. Rumen acids are buffered by saliva and by feed-additive buffers, such as sodium bicarbonate.

When acid production exceeds the rumen’s ability to buffer and absorb the acids, rumen pH drops, creating a cascade of events which work together to predispose the animal to laminitis.

Proper ration balancing is critical to provide enough energy for milk production by optimizing carbohydrate fermentation. The ration, however, must also maintain rumen health and avoid acidosis in order to support hoof health. A number of factors have to be considered.

High-producing dairy cattle require large amounts of energy for cost-effective milk production so feed grains and byproducts are used as part of dairy rations.

High-energy feed ingredients are energy-dense, predominantly from starch, and thus produce large amounts of acid when fermented in the rumen.

Grain levels must be carefully controlled. Attention must also be paid to the rate of non-fibrous carbohydrate (NFC) fermentation in the rumen.

Some rules of thumb:

• At least 15 percent of ration particles should exceed 1.5 inches in length.

• Do not exceed 36 to 38 percent dietary NFC.

• Avoid slug-feeding grain; no more than 8 pounds at one time.

• Limit rapidly fermentable starch and sugars to less than 20 to 30 percent of the NFC.

• Use transition rations to adapt the rumen to larger amounts of NFC. Target an NFC level of 32 to 33 percent.

• Provide adequate soluble and degradable protein for ready access by rumen microbes.

• Forage NDF should exceed 19 to 21 percent depending on forage digestibility and inclusion level of non-forage fiber.

• Feed forages before grain or concentrates if not using a total mixed ration.

• Forage or TMR should be available 24 hours per day.

• At least 50 to 60 percent of cows that aren’t eating should be chewing their cuds a few hours after feeding time.

• Add buffers to high-production diets.

It is well documented that one major factor is ration changes that have an effect on rumen fermentation, NFC availability and resulting acid production. Poor hoof health does not occur overnight. Cows can exhibit signs of laminitis four to eight weeks after calving.

In these situations, the transition of dry cows to the early lactation ration can lead to rumen acidosis. When making these ration changes, keep some things in mind:

• Change the energy level between rations by less than 10 percent. For example, if the net energy lactation (NEl) level of the far-off dry cow ration is .65 Mcal per pound dry matter, the next ration should not exceed .715 NEl Mcal per pound dry matter.

• To minimize transition acidosis, use a minimum of two rations (close-up dry cow and fresh cow rations) to allow cows to step up from the far-off dry cow ration to the early lactation ration.

Other nutritional tools
A number of other nutritional components can be incorporated to help offset lameness in dairy cows. These include:

1. Amino acids – Cysteine, histidine and methionine play important roles in hoof horn production.

2. Biotin – A water-soluble B vitamin, biotin has shown to be the vitamin of greatest importance to horn production. Biotin is essential to two major processes in hoof growth and formation including keratin protein synthesis and formation of the intercellular “cement.”

Biotin-supplemented dairy cows showed a reduced susceptibility to disease of the claw such as sole ulcers, dermatitis digitalis and horn deterioration.

3. Calcium (Ca) – This plays an important role in horn production, as calcium in the epidermis controls horn formation and is required for activation of enzymatic activity essential to the final steps in the production of the mature horn cell.

The onset of lactation pulls heavily on calcium stores and can limit calcium availability for other processes such as horn formation.

4. Copper (Cu) – This is essential for activation of many enzymes. Copper activates a key enzyme responsible for formation of chemical bonds between keratin (key protein component in horn tissues) filaments.

Researchers reported that cattle suffering from a subacute copper deficiency were more susceptible to heel cracks, foot rot and sole abscesses.

5. Selenium (Se) – This may contribute to protection and maintenance of an intercellular cementing material. The problem appears to be with excessive supplementation. Excessive selenium may be damaging to horn cells by reducing chemical bonds within keratins.

6. Zinc (Zn) – It is a component of over 200 enzyme systems, several of which are involved in horn formation. Zinc plays a central role in the formation of keratin proteins. Use of organic/chelated forms of zinc have been shown to improve hoof integrity.

7. Vitamin A – It is needed for normal growth and development of skeletal and epithelial tissues which includes claw epidermis.

Conclusions
Attention to proper hoof health is an important part of day-to-day dairy management. By improving hoof quality and reducing the effects of hoof injuries and diseases, significant improvements can be made to dairy profitability.

While properly managed nutrition is a key component of overall hoof health and reduction of lameness, it is just a part of the total program.

Hoof health management requires a team approach and involves the dairyman, his employees, his veterinarian and nutritionist. PD

References omitted due to space but are available upon request. Click here to email an editor.

PHOTO
Laminitis in dairy cattle has been associated with rumen function and production of excessive organic acids in the rumen. Incidence of laminitis also reflects improper ration formulation or feeding management. Photo by PD staff .

Steve Blezinger
Nutrition and Management Consultant
Reveille Livestock Concepts