This dissertation is the product of two behaviour studies and an in vitro fermentation trial. Both behaviour studies were conducted at the Ashburton Racehorse-Training Centre in Ashburton, near Pietermaritzburg in KwaZulu- Natal. The first behaviour study evaluated differences in behaviours obtained through feeding either twice or four times daily. This trial showed (P<O.OO1) that horses fed twice a day spend a greater proportion of their day in stereotypic or vice-like behaviours. Horses eating four times a day ate less hay (P<O.OO1) and more concentrate (P<O.05) than horses being fed twice a day. Horses in both yards ate more hay (P<O.05) when exercise intensity was increased. Defecation frequency was higher on days when exercise intensity was high (P<O.05) and in the yard where horses were fed four times per day (P<O.O1). Faecal weight was greater (P<O.05), horses lay down more frequently (P<O.05), spent more time eating concentrate (P<O.OO1) and less time eating hay (P<O.OO1) when horses were fed four times per day. Fillies spent more time (P<O.05) eating hay than geldings. The second behaviour study was conducted within one yard only and considered the effects of changes in management strategies on the incidence of stereotypic behaviour. The results did not indicate that changes in management related to exercise intensity would have an effect on behaviours exhibited. However this trial did demonstrate that a reduction in feed intake on days when exercise is reduced will reduce the incidence of stereotypic behaviours. Horses reduced the time spent eating hay when exercise was reduced except that when feeding frequency was reduced in conjunction with reduced exercise, more time was then spent eating hay (P<O.OO1). It was found that fillies spent more time licking surfaces (P<O.OO1) and weaving (P<O.O1) than geldings, which were more aggressive (P<O.OO1) and ate more bedding (P<O.05) than the fillies. All the horses were more alert (P<O.OO1) on days of moderate exercise except when feed was reduced in conjunction with reduced exercise, so that horses were less alert (P<O.OO1) and more time resting (P<O.OO1). The in vitro study was conducted at the department of Animal and Poultry Science at the University of KwaZulu-Natal, Pietermaritzburg. This was a dilution trial, using different ratios of maize and Eragrostis curvula. It was shown that as the proportion of maize in the ration was increased so the digestibility and the degradability of the ration increased (P<O.OO1). It was also shown that the adapted two stage digestion techniques described by Tilley & Terry (1963) had lower supernatant pH levels than the samples that underwent microbial digestion only. This was accounted for by a problem with the methodology. The trial had hoped to show a dramatic decrease in pH and increased rates of gas production when the maize portion of the sample was increased. From the results established during this trial it is clear that application exists in the adoption of this method in in vitro feed analysis in the horse industry.· The behaviour studies significantly linked the incidence of stereotypic behaviour to feeding and nutritional management in racehorses. Some explanations of the noted behaviours can be elucidated through the development of in vitro protocols, where hindgut pH, degradability and fermentation of different ration mixtures elicit responses in physical terms. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2007.

Upper airway endoscopy at rest has been the diagnostic method of choice for diagnosing equine upper respiratory tract (URT) disease since its development in the 1970´s. The development of high-speed treadmill endoscopy (HSTE) improved the sensitivity of URT endoscopy by allowing the examiner to observe the horse’s nasopharynx and larynx during exercise. However, the level of exertion achieved during HSTE may not always represent that achieved during normal exercise as surface, rider, tack, and environmental variables are altered. Recently, the development of dynamic overground endoscopy (DOE) has addressed some of those shortcomings. A retrospective study was undertaken to describe the upper airway abnormalities detected during DOE in horses presenting with poor performance and/or abnormal respiratory noise in South Africa. Patient records of Thoroughbred racehorses undergoing DOE from November 2011 to August 2012 by the Onderstepoort Veterinary Academic Hospital were reviewed. Data collected included signalment, primary complaint, distance exercised, maximum speed attained, and dynamic airway abnormalities detected. XIII A second study was carried out to evaluate agreement within and among examiners of three grading systems for laryngeal function at exercise. The grading systems assessed were an existing system for grading axial deviation of aryepiglottic folds (ADAF), a modified system for grading recurrent laryngeal neuropathy (RLN) at exercise, and a proposed system for grading vocal cord collapse (VCC). For investigation of intra-observer variability, recordings were watched by two of the investigators at the same time, on two different occasions, in real time, slow motion, and at frame-by-frame speed. To evaluate inter-observer variability, recordings were watched by four investigators on one occasion, as described for investigation of intra-observer variability, and scoring sheets completed. Kappa agreement was calculated for both intra- and inter-observer sessions. Fifty-two horses that underwent DOE for investigation of poor performance and/or abnormal respiratory noise were identified. The main abnormalities detected included dorsal displacement of the soft palate (DDSP) (13/52 horses, 25%); recurrent laryngeal neuropathy (RLN) (17/52 horses, 33%); axial deviation of the aryepiglottic folds (ADAF) (21/52 horses, 40%) and vocal cord collapse (VCC) (18/52 horses, 35%). A total of 40 horses presented one or more abnormalities of the URT (77%). Fifteen horses (29%) had a single abnormality, and 25 horses (48%) had multiple abnormalities. Results at frame-by-frame speed from the intra-observer evaluations for all the conditions showed substantial agreement for RLN by both observers (K = 74 - 80). Intra-observer evaluations for VCC were moderate to substantial (K 53 – 63). ADAF was the most difficult URT abnormality to assess for both observers, and agreement within observers was only fair to moderate (K = 36 - 52). Inter-observer evaluations for RLN showed substantial to moderate agreement (K = 62). Inter-observer evaluations for VCC showed moderate agreement (K = 47 – 54), and inter-observer evaluations for ADAF showed only slight to fair agreement and were the lowest for all the conditions (K = 14 – 22). This study showed that DOE is a useful technique for providing valuable information about disease of the URT. Finding multiple abnormalities in 48% of horses examined using DOE suggests that DOE may be indicated even for those horses with an obvious abnormality found during resting endoscopy. The intra-observer evaluations showed that RLN had higher agreement values than those for ADAF and VCC at all speeds, and that ADAF had lower agreement values than those for VCC and RLN at all speeds. Inter-observer agreement was less than intra-observer agreement, presumably because more observers were involved in the inter-observer assessment. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Companion Animal Clinical Studies / unrestricted

CAPES / O presente trabalho tem por objetivo apresentar uma nova técnica de instrumentação para estudo dos diferentes tipos de andaduras realizadas por equinos, utilizando sistemas baseados na tecnologia de sensoriamento ótico quase-distribuído, redes de Bragg em fibra ótica-FBG. Essa técnica poderá ser usada como ferramenta auxiliar de diagnóstico precoce de lesões relacionadas ao sistema locomotor do cavalo, principalmente na porção distal do dígito, uma das causas mais comuns de aposentadoria destes quando atletas. São apresentadas, portanto, duas técnicas de instrumentação in vivo: a primeira t´técnica consiste na fixação de FBGs sem encapsulamento, diretamente na parede dorsal do casco em cada um dos membros de três cavalos atletas em treinamento; a segunda técnica apresentada ´e o desenvolvimento de um protótipo sensor com formato de ferradura encapsulado em material compósito reforçado com fibra de carbono, este método foi utilizado na instrumentação de dois equinos também em fase de treinamento. O primeiro método permite avaliar o comportamento do casco em diferentes fases da passada, durante as andaduras passo e trote. A segunda técnica, com o elemento sensor encapsulado, permite avaliar diferentes tipos de andadura, como passo, trote e galope sob condições de treinamento. Estas duas técnicas de instrumentação, utilizando sensores FBGs, se mostram promissoras para o estudo clínico e biomecânico de equinos, em avaliações m´médicas ou até mesmo durante treinamentos ou competições. / The main goal of this paper is to study the viability of the application of the system based on the optic sensing almost distribute (Fiber Bragg Gratings-FBG) technology, to study different kinds of equine gaits and how it is a possible helpful tool to early diagnose of injuries related to the locomotor system of the horse, mainly the distal part of the digit, which is one of the most common reasons for retire of athlete horses. Two different technics are presented in vivo: The first one consists in the attachment of the FBGs without encapsulation, directly on the wall of the hoof of each member of three athlete horses during training; the second technic presented, is the development of a prototype sensor with the same form of a horse shoe, encapsulated in a composite material reinforced with Carbon Fiber, this method was used in two horses during training as well. The first method allowed evaluate the behavior of the hoof in different phases of the horse gaits, such as walk and trot. The second technic, with the sensor element now encapsulated, allowed to evaluate different types of equine gaits, like walk, trot and run under training conditions. Both of the instrumentation using FGBs sensors technics were considered promising to clinical and biomechanics equine study in the medical evaluations or even during training or competition.