Degree Type

Thesis

Date of Award

2018

Degree Name

Master of Science

Department

Theses & dissertations (Interdisciplinary)

Major

Interdisciplinary Graduate Studies

First Advisor

Jennifer A. Schleining

Abstract

Bovine lameness is an economic drain on producers and is a welfare issue. There are many causes of lameness; however, most causes involve the hoof. One of the supporting structures of the hoof is the interface between the hard epidermal layer and the sensitive dermal layer and is referred to as the lamina. Lamina consist of leaflets of tissue that interdigitate with one another to allow for constant renewal and remodeling of these hoof attachments. Systemic or traumatic insults can compromise the integrity of the lamina and may result in reduced ambulatory capabilities of the animal, pain, and a myriad of hoof lesions.

The first study in this thesis describes the biomechanical properties of the laminar junction in market weight cattle scored as having normal mobility. Following foot collection at harvest, one hoof was immediately processed for biomechanical testing and the opposite hoof was processed and tested six months later. The outcome of this study determined that duration of freezing may affect the test results of biomechanical specimens which is in contrast to what is currently published in the literature.

In the second study, cattle were observed and scored over a range of mobility using the North American Meat Institute mobility scoring system. Hooves were collected from the scored animals and biomechanical specimens were prepared and tested to determine biomechanical variables of the lamina across a range of mobility. It was determined in this study that the strain at break at the lamina for animals with reduced mobility was significantly higher than for animals with uninhibited mobility. This would suggest that the lamina in animals with altered mobility has decreased integrity through an increase in elasticity as observed by a dynamic increase in length of the lamina under stress. The exact mechanism by which this occurs is the focus of future research.

Copyright Owner

Ray Jeffrey Lee

Language

en

File Format

application/pdf

File Size

62 pages

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