Cow/Calf Corner... Foot Rot in Cattle
Dr. Rosslyn Biggs, OSU College of Veterinary Medicine Extension Beef Veterinarian
Foot rot is an infectious disease of cattle, causing swelling and lameness in at least one foot. The associated lameness often leads to decreased appetite and overall performance. It is not uncommon for multiple animals in a herd to be affected.
Foot rot can occur in cattle of all ages, and cases are often seen in wet and humid conditions, but can also occur when it is hot and dry when cattle congregate together. Standing in pens or lots heavily contaminated with feces and urine softens the skin and provides high exposure to the causative bacteria. High temperatures and humidity will also cause the skin to chap and crack, leaving it susceptible to bacterial invasion.
Fusobacterium necrophorum is the bacterium most often isolated from infected feet. This organism is present on healthy skin, but it needs injury or wet skin to enter the deeper tissue. F. necrophorum appears to act cooperatively with other bacteria to cause disease. Moisture, nutrient deficiency, injury or disease can result in compromised skin or hoof wall integrity, increasing the likelihood of the bacteria invading the skin.
Diagnosis of foot rot is typically made following thorough cleaning and examination of the foot particularly the space between the digits following sudden lameness. Fever may also be noted. If treatment is delayed, deeper structures of the foot may become affected, leading to a chronic condition and decreased chance of recovery.
Once foot rot has been confirmed, treatment should be administered. Antibiotics and pain medications along with addressing housing and environmental conditions should be considered. A vaccine does exist, but producers should consult with their veterinarian to see if it is a good option. As with most infectious diseases, affected cattle should be isolated.
Notable improvement should be seen within three to four days following treatment. If the animal is not responding during this period of time, it should be evaluated by a veterinarian. “Super foot rot” has been seen in certain areas of the country. It is more aggressive and is not as responsive to standard treatment.
Additionally, there are multiple other conditions that cause cattle lameness. Producers should consult with their veterinarian on diagnostic and treatment options particularly for lameness that does not resolve in the time expected. Approximately 20 percent of all diagnosed lameness in cattle is actually foot rot.
Grazing Summer Cover Crops
Paul Beck, Oklahoma State University Extension Beef Cattle Specialist
When we think of warm season annual forage crops the summer annual grasses such as pearl millet and sorghum sudan quickly come to mind. Often warm season annual forages are thought of as an emergency source of hay for their ability to produce a lot of forage quickly during periods of dry weather when other forage sources are limited. However, they are much more versatile than just providing a quick hay or silage crop.
Recently, there has been lots of interest in using cover crops in cropping systems to provide agronomic benefits such as adding soil organic material, soil cover for wind and water erosion control, increasing soil microbial diversity, and weed suppression, among others. Now producers have found that the cover-crop benefits can be maintained when cover crops are grazed by livestock, providing some direct economic benefit along with the benefits to the cropping enterprise.
Thanks to emphasis placed on cover crops and soil health, the species considered for use as forage crops during the summer has broadened beyond the traditional sorghums and millets to include diverse mixtures of legumes, grasses, and broadleaf species. Cover crops can be as simple as a single species or more complex multiple species blends including 10 to 12 species, selected for their agronomic benefits with little regard for forage production attributes.
The species in these blends are included for their agronomic benefits, but many appear to be productive as forages and surprisingly palatable.
There is not a lot of information on the forage and grazing characteristics of many of the components of cover-crop blends.
The rule of thumb is to start grazing sorghums, sudangrass, and millet at around 30 inches in height and leave a residual height of 6 to 10 inches. This is also what I recommend for cover crop blends until we know better.
Prussic acid can be an issue with any of the sudangrass or sorghum species. It can build up any time the plant has undergone a period of stress. Common plant stresses that can induce buildup include drought, frost and herbicide application. It is generally best to avoid grazing 10 - 14 days after any stress period.
Another potential issue these forages is nitrate accumulation, which occurs when plants take up nitrogen during a period of little to no growth. This accumulation of nitrate is generally in the base of the stem of the plant. If nitrate accumulation is suspected, testing is recommended.
Millets do not accumulate prussic acid but can accumulate nitrates.