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Title: Mechanical tests and computational models for evaluating the cushioning performance of dairy cow cubicle beds
Author: Tierney, Gary
ISNI:       0000 0001 3533 3620
Awarding Body: University of Glasgow
Current Institution: University of Glasgow
Date of Award: 2002
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Comfort from dairy cow synthetic beds is quantifiable using animal observation trials, but these are expensive and time-consuming. Finite Element Analysis (FEA) is a computational technique used for engineering stress and deformation analysis. Accelerometric testing is used to test the cushioning offered by athletics tracks and synthetic field sports surfaces. In the current work all three of these research methodologies were used to assess the comfort performance of two commonly used cubicle or free-stall synthetic beds, rubber-crumb mattresses and ethylene vinyl acetate (EVA) mats. The aim of the animal observation study was to gain primary data on the general health and milk production performance of cows housed in cubicles with the two bed types, as well as on the specific matters of leg-joint injury and lying down and getting up behaviour. The main findings were that cows on rubber-crumb mattresses had fewer leg joint injuries and showed lying behaviour that implied greater comfort, but these advantages did not show up in the milk production data. FEA was used to assess free-stall bed cushioning during the quasi-static push of the getting-up movement of a cow and to predict variation in performance in time or as a result of an altered bed specification. Laboratory quasi-static force-deflection responses of the materials of the two bed types were closely matched in the Abaqus FE code, giving confidence in the integrity of the model. Accelerometric testing was used for the assessment of two further performance criteria vital to a bed purchase decision. First, impact absorption performance during the dynamic lying down movement of a cow and, second, variation in cushioning performance in time as a result of having been used by a herd for three years. The results from the accelerometric tests showed that the EVA foam cubicle bed was the more time-stable product of the two.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
Keywords: Animal housing