Call number: LD2668 .T4 1979 E37 / Master of Science

Call number: LD2668 .T4 1979 G45 / Master of Science

Call number: LD2668 .T4 1979 M25 / Master of Science

No description available.

Four Greyhound dogs and six horses were utilized to study the physiological mechanisms associated with the development of an exercise training-induced hypervolemia. The animals were used in two separate experiments and were trained for 14 days on a treadmill ergometer and the data were used to formulate conclusions regarding the physiological and practical implications related to the phenomenon. The data reported in this dissertation indicated that exercise training will cause an expansion of the plasma volume in the Greyhound dog (+27%, P < 0.05) and the horse (+29.1% P < 0.05). Physiologically the result is similar in man, the dog, and the horse, however, the mechanisms by which this adaptation is reached appears to differ in each of the species. In the dog, water intake (+33%, P < 0.05) appears to be the primary mechanism for the increase in fluid volume. In the horse, renal control mechanisms (24-hr urine output -24.5%, P < 0.05) appear to be the primary mechanism with those that control the retention of solutes other than sodium predominating over those that control the reabsorption of sodium and water. Based upon the literature, it appears that in man, renal mechanisms predominate the hypervolemic response and mechanisms which control the conservation of sodium appear to be most active in the defense of the tonicity and volume of the vascular compartment. These species differences are important to the understanding of the physiology behind the onset of the training-induced hypervolemia and they provide pertinent information upon which decisions regarding the choice of animal models for future research.

Historically, horse trainers have relied primarily upon repetition, negative reinforcement, and punishment to teach new behaviors. Positive reinforcement has been eschewed, largely on the basis of the wides read belief that positive reinforcement is not effective with horses. Additional difficulties in the timely application of such reinforcement have further inhibited its use. After repeated pairing of an auditory stimulus with an established primary reinforcer, the auditory stimulus was predicted to be a reinforcer. An equine subject was then successfully trained to perform five different, novel tasks using only the auditory stimulus. Subsequently, extinction of behavior was noted in the absence of the conditioned reinforcer. Implications for many phases of horse training were discussed. Some weaknesses of the present study were noted along with suggested issues for future investigations.

The purpose of this study was to develop an effective method for trailer loading horses based on the principles of positive reinforcement. Target training and shaping were used to teach trailer loading behavior in a natural setting. Five AQHA mares were selected for this program. All five had been loaded before through the use of punishment. A two-horse trailer was used. Approximations to loading and inappropriate behaviors were the dependent variables. When intervention started the target was moved to various locations inside the trailer. Subjects started training on the left side of the trailer. After a subject was loading in the left side they were moved to the right side, then to loading half on the right and half on the left, then they were loaded by a different trainer, and into a different trailer. For one subject a limited hold was utilized, as well as a companion horse.

Laminitis is one of the most common multifactorial diseases of horse limbs. Recent studies show that 90% of this disease is due to endocrinological diseases such as Cushing's syndrome or equine metabolic syndrome. In available literature, there is not much relevant information on the relationship of laminitis to hematological and biochemical blood parameters. This diploma thesis "Changes in selected blood parameters of horses" evaluates biochemical and haematological blood parameters in connection with laminitis in 27 sick horses. It statistically compares the differences in blood parameters between healthy and sick horses.

Orientador: Marcílio Dias Silveira da Mota / Resumo: Clicar acesso eletrônico abaixo. / Abstract: Click electronic access below. / Mestre

Orientador: Fernanda da Cruz Landim e Alvarenga / Coorientador: Paula Ripamonte / Banca: Frederico Ozanan Papa / Banca: Cezinande Meira / Banca: Márcio Teoro do Carmo / Banca: Claudia Barbosa Fernandes / Resumo: As alterações observadas nos folículos pré-ovulatórios dos mamíferos a partir da onda pré-ovulatória de LH são mediadas por fatores de crescimento como AR e ER, que induzem a expansão das células do cumulus e maturação oocitária. O LH também estimula a deposição de ácido hialurônico mediada pela enzima HAS-2. Em eqüinos, já foi caracterizada a expressão de HAS-2, AR e ER em resposta à administração de hCG em folículos pré-ovulatórios, mas sua ação em folículos imaturos não está esclarecida, embora tenha sido demonstrada a expansão precoce do cumulus após sua administração em folículos menores de 30mm. O objetivo deste estudo foi caracterizar o padrão de expressão de ER, AR e HAS-2 em folículos de eqüinos em diferentes estágios de maturação, submetidos ou não ao tratamento com EPE e hCG. Para isso, recuperamos células foliculares por OPU de folículos de diversos tamanhos, em 3 ou 24 horas após estímulo gonadotrófico exógeno, e avaliamos a expressão gênica de ER, AR e HAS-2 por PCR em tempo real. O tratamento com hCG induziu a expressão de ER em folículos imaturos e pré-ovulatórios, demonstrando sua capacidade de indução da maturação folicular precoce, e houve tendência do mesmo efeito ser obtido com a expressão de HAS-2, embora não tenha sido estatisticamente comprovado. O EPE apresentou efeito menor que a hCG na indução da expressão de ER, o que pode ser justificado pelo mecanismo de down regulation que o LH exerce sobre a ativação dos fatores de crescimento ligados ao EGF, como a ER e a AR / Abstract: The modifications observed on mammalia n follicles after the pré-ovulatory surge of LH are mediated by growth factors like epiregulin (ER), which is responsible for the cumulus cells expansion and interfere with the oocyte maturation . The LH also stimulates the deposition of hyaluronic acid mediated by the hialuronan synthase -2 (HAS-2). In horses , the expression of HAS-2 and ER was already characterized in pre-ovulatory follicles , after the administration of hCG. In the present experiment we were able to demonstrate that the hCG is also able to induce the expression of ER in equine follicles smaller than 30mm in diameter , confirming an ability of immature follicles in responding to hormonal stimuli. Although no statistic differences were observed among groups a tendency to the same effect was also observed for the HAS-2. Similarly, the use of EPE stimulated the expression of ER, but when EPE and hCG were combined a decrease in expression was observed. This observation indicates a mechanism of down regulation exerted by the LH on the ER and HAS expression / Doutor