A remote control sampling technique was developed for the collection of oesophageal
fistula samples from goats. Number and size of samples can be varied and collected
throughout the day without disturbing the animal's normal feeding behaviour. The
equipment developed and tested in this study consists of an oesophageal fistula valve which
allows the fistula to be opened and closed, a rechargeable battery pack and motor to
operate the valve, a portable radio and receiver to activate the valve motor, and a harness
to attach the equipment to the body of the animal In addition, a closing device to
effectively seal large oesophageal fistulae (> 1 050 mm²), which in turn is required to
accommodate the valve, was developed. During field tests with the fistula valve, 10 % of
I 027 sampling attempts failed due to blockage of the valve, and an average of 1.3
incidences of equipment failure were recorded per animal per sampling day, from an
average of 9.9 extrusa collections per day. Observed feeding behaviour (grazing/browsing)
as well as grass / bush ratio of fistula valve and standard fistula bag samples of four goats,
formed the basis for the evaluation of this technique. In addition, extrusa recovery rates,
measured under controlled conditions, were used in the evaluation of this sampling method
Differences in extrusa composition between the fistula valve and fistula bag techniques
varied substantially during the browsing period within a camp and also between camps.
Furthermore, during high frequencies of observed grazing, there were large differences
between the fistula valve and fistula bag methods. During this study, the fistula valve
technique provided a more realistic estimate (R²=.91) of the observed feeding behaviour
of goats than the fistula bag technique (R²=.63). Under controlled conditions, the large
oesophageal fistula, with or without the valve, enables high and consistent extrusa recovery
rates (87 % recovery; SD 7.5). / Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1993.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/10900 |
| Date | January 1993 |
| Creators | Raats, Jan Gabriël. |
| Contributors | Tainton, Neil M., Trollope, Winston S. W. |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
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