Characterisation of Claw–floor Contact Pressures for Standing Cattle and the Dependency on Concrete Roughness
ABSTRACT Inadequate properties of concrete floors in livestock buildings seem to be an important cause of cattle lesions. High local pressures on claw tissues may contribute to damage of the claw. Monitoring of foot-to-ground pressure distributions may provide insight in the relation between high local pressures and foot lesions.In the current research, the pressure distribution of the foot-to-ground contact area was recorded using thin film tactile sensors. During the experiments, the sensor was located between previously prepared bovine claws and concrete samples with different surface roughness. The measurement procedure permitted a gradual increase in the vertical load on the claws at a test bench, while at the same time the contact area and the pressure distribution could be registered. Five different levels of surface roughness were obtained by finishing fresh concrete samples with a metal float, a wooden float or a brush, and by washing the concrete surface to two different degrees.The results showed a clear increase in contact area with increasing pressure. The abaxial wall and bulb of the claws had the major load-bearing function. The metal-floated concrete resulted in the largest contact area and the lowest pressures, while the washed concrete resulted in much smaller contact areas and higher pressures. Other finishing methods gave intermediate results.The maximum pressure under a load of 4 kN was about twice as high on a wooden-floated or lightly washed surface (around 40 MPa), compared to a metal-floated surface (around 20 MPa). On the severely washed out surface, the maximum pressure was even four to five times higher. This may indicate a higher risk on claw lesions due to local overload.
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Article: Toe Lesions in Dairy Cattle[Show abstract] [Hide abstract]
ABSTRACT: For the past several years these authors have been studying toe lesions in cattle with a specific interest in their pathogenesis and underlying causes. Our work to date indicates that there are 5 conditions that typically predispose to lameness and toe lesions. These include: toe ulcer, white line disease, thin sole toe ulcer, corkscrew claw and trauma-related lesions affecting the tip or apex of the claw. In our experience, toe ulcers associated with laminitis are relatively rare. White line disease lesions in the toe are slightly more common and are sometimes associated with inappropriate trimming techniques (i.e. such as excessive removal of the axial or inside wall). Laminitis is believed to be a potential contributor to white line lesions in the toe as a result of its effects on horn quality. Corkscrew claw is relatively common and frequently predisposes to toe lesions that result in abscess formation by a couple of different routes. Trauma-related lesions that result in toe abscess formation are more common in feedlot cattle where hyper-excitable animals are prone to traumatic injuries of the toe during processing or hauling. For dairy operations throughout the Southeast, one of the most common lesions is the "thin sole toe ulcer" (TSTU). This lesion is a consequence of excessive thinning of the sole associated with accelerated claw horn wear and on occasion over-trimming. These lesions are particularly prevalent, difficult to treat and predispose to lesions that frequently result in chronic lameness. In the following we describe these lesions with particular emphasis on discussion of the TSTU. INTRODUCTION Toe lesions in cattle are common causes of lameness. In housing systems where the rate of sole horn wear exceeds the rate of growth excessive thinning of the sole is likely to occur. Previous work has demonstrated that claw horn hardness is influenced by nutrition, contact with manure slurry and moisture content of claw horn 18 . Claw horn is continually exposed to high moisture conditions particularly during the hot and humid summer months. Heat stress abatement procedures require that cows have access to sprinklers and fans, misters or high pressure fogging systems. Claw horn moisture content is also affected by manure management systems based on flushing of fresh or recycled water to clean floors in barns, holding areas and travel lanes. Wear rates are also affected by the spatial layout of facilities which require cows to walk long distances to and from barns and milking areas. This is exacerbated by abrasive flooring conditions that include sharp turns and sloped walkways. Excessive sole horn wear is especially common in new installations where freshly hardened concrete creates a particularly abrasive surface as a consequence of the presence of surface aggregate which naturally forms on the flooring surface as the concrete cures. This observation has become so commonplace as to have its own name "New Concrete Disease" 2, 4, 12 .
Conference Paper: Pressure Distribution on Bovine Claws in Slatted Concrete Floors[Show abstract] [Hide abstract]
ABSTRACT: The design of concrete slatted floor is a compromise between good drainage capacity and good support for the feet. High local pressures on claw tissues may contribute to damage of the cattle claw. Slatted floors may be more hazardous than solid ones. In this paper results are presented from a study where the contact pressure between a prepared bovine claw and slatted floors was recorded using thin film tactile sensors. The results showed a clear increase in contact pressure when slatted floors were used. The local contact pressure of the sole and wall zone was recorded to be 2-3 times greater on a slatted concrete floor than on a solid concrete floor Introduction A slatted concrete floor is commonly used as a draining floor in the passageways of cattleXVI CIGR World Congress, Bonn, Germany; 09/2006
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ABSTRACT: Purpose – Reviews the benefits and potential application of tactile sensors for use with robots. Design/methodology/approach – Includes the most recent advances in both the design/manufacturing of various tactile sensors and their applications in different industries. Although these types of sensors have been adopted in a considerable number of areas, the applications such as, medical, agricultural/livestock and food, grippers/manipulators design, prosthetic, and environmental studies have gained more popularity and are presented in this paper. Findings – Robots can perform very useful and repetitive tasks in controlled environments. However, when the robots are required to handle the unstructured and changing environments, there is a need for more elaborate means to improve their performance. In this scenario, tactile sensors can play a major role. In the unstructured environments, the robots must be able to grasp objects (or tissues, in the case of medical robots) and move objects from one location to another. Originality/value – In this work, the emphasis was on the most interesting and fast developing areas of the tactile sensors applications, including, medical, agriculture and food, grippers and manipulators design, prosthetic, and environmental studies.Industrial Robot 05/2005; 32(3):268-281. · 0.62 Impact Factor