Source: SDSU Extension | March 29, 2019
By Alvaro Garcia, SDSU Extension agriculture and natural resources program director & professor
Spring rains produce conditions that can increase lameness in beef cattle. Mud is among the predisposing causes for cattle lameness. Wetness decreases hoof hardness and increases the incidence of claw lesions. Research has shown that nearly one-third of the total water absorbed by the hoof happens during the first hour of exposure to high moisture resulting in heavier and softer hooves. Although not as prevalent as observed in the dairy industry, when it happens it may lead to decreased feed intake, lower weight gains, reduced reproduction (both in cows and bulls), and greater culling rates.
Beef producers address muddy conditions by creating mounds where cattle can lay down on higher, drier ground. There is minimal cost to establish a mound particularly when the shaping takes place previous to installing fences, bunks, watering, and aprons. With a slope of usually 3 to 5 percent, mounds work best when built parallel to the direction of the slope and are located in the center-line of the pen. In older lots these mounds can be newly built or strengthened periodically by adding manure and dirt. Mounds, however, do not last forever and more than likely will need some reshaping with additional material yearly. The main concern is when either by accident small rocks or pebbles are present in the material used to build them.
Standing cattle apply a significant amount of pressure to any surface. In a 2017 University of Kentucky article researchers compared this pressure with that of other livestock, humans, and farm equipment. Pressure was measured in pounds per square inch (psi) or, more accurately, pound-force per square inch. One Psi is the pressure that results from a force of one pound-force on an area of one square inch (Table 1). From the data in the table it is obvious that aside from tractors, cattle and horses exert the most pressure per square inch, even more than a 50-ton bulldozer!
The reader is probably aware of the “action-reaction physics principle”; in simple terms it states that every action, is followed by an equal and opposite reaction force. For example, if you press a button, the button presses back with the same amount of force! This brings us back to the issue of beef cattle mounds and the presence of stones or other foreign objects. When mounds are not maintained (or reshaped) regularly, rains or any other source of running water erodes their surface and expose these underlying hard objects. Consider now the force cattle make on this surface (Table 1), and the resulting pressure back on hooves that have already been softened by constant exposure to water. When cows walk however, they apply this pressure to two extremities at a time, increasing the pressure per square inch (Table 2). As a result, cow’s extremities sink deeper in the mud reaching oftentimes the subjacent hardened surface, which could have hard objects not visible at plain sight.
|Table 1 Pressure created by different stressors|
|Utility terrain vehicle||14|
|Higgins et al. Revised 2017|
|Table 2 |
Pressure created by walking humans and livestock
|Higgins et al. Revised 2017|
Although not as prevalent as lameness in dairy cattle, there are infectious agents (i.e. Fusobacterium necrophorus and Bacteroides melaninogenicus) that can cause cattle lameness, foot rot, and digital dermatitis or hairy heel warts. Warts are most likely caused by Spirochetes, which is still one of the leading causes of lameness in the U.S. Beef producers should manage cattle attempting to keep hooves as dry as possible. Since this is very difficult in most farms particularly during spring or in unusually wet years, it is important to find ways to reduce the incidence of injuries to the hoof. This can be accomplished by periodically walking the pens to remove foreign objects and being careful with the type of material used to reshape the mounds.