Protein has been identified as a major reason that people purchase a horse feed, with anecdotal
explanations offered for the poor prediction of response of horses to their rations, particularly in the
sport horse market. The current research identifies through hierarchical cluster analysis that the
myriad of riding feeds offered on the South African market fall into only four simple categories on
the basis of wet chemistry. Feeds were subjected to the in vitro gas production technique (IVGPT)
described by Pell and Schofield (1993), using equine faecal inoculum. Gas profiles, corrected for
control fermentation profiles in the absence of substrate, were fitted to the model described by
Campos et al. (2004) to derive GP kinetics. Gas production kinetics, and information in respect of
pH, degradation efficiency, lag time and apparent and true digestibilities were obtained. The feeds
were tested for glycaemic response in miniature horses using the hexokinase method with
deproteinization using an auto analyser (Roche Diagnostics). Blood glucose parameters of feeds
(mean, peak, slope and time to peak and area under the curve) in each group were compared by
analysis of variance and regression with covariates. In vivo analysis of rates of passage and
digestibility using using post-prandial percentages of acid insoluble marker collection was used to
study the gastrointestinal process, to indicate foregut and hindgut compartmental flow. The need
to balance nitrogen levels with a proportional supply of fermentable carbohydrate contradicts
widely used protein intakes in the horse. In vitro fermentation was used in an analysis of nutrient
synchrony, to identify optimal fermentative capacity for utilization of horse feeds. The
characteristics of horse feeds were related to requirement and were composited in an analysis of
the representation of horse feeds that would best reflect optimal utilization in the horse, to produce
a method of feed characterisation that would lead to the optimal prediction of response of horses to
feeds offered to South African horses. / Thesis (Ph.D.Agric.)-University of KwaZulu-Natal, Pietermaritzburg, 2011.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:ukzn/oai:http://researchspace.ukzn.ac.za:10413/8313 |
| Date | January 2011 |
| Creators | Young, Marion Belinda. |
| Contributors | Laing, Mark D. |
| Source Sets | South African National ETD Portal |
| Language | en_ZA |
| Detected Language | English |
| Type | Thesis |
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