Perfil de testosterona e parâmetros seminais de garanhões da raça Mangalarga Marchador dentro e fora da estação reprodutiva

• Autor(a) principal: Neves, Maria Gazzinelli
• Data de Publicação: 2014
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5823
• topic: Mangalarga (Cavalo); Cavalo - Reprodução; Cavalo - Sêmen; Cavalo - Testosterona; Mangalarga (Horse); Horse - Reproduction; Horse - Semen; Horse - Testosterone; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::REPRODUCAO ANIMAL

The aim of this study was to evaluate the reproductive parameters and the profile of testosterone release and their average concentrations in Mangalarga Marchador stallions. It was evaluated in two periods, during breed season and outside the breed season, in Viçosa, Muriaé and Teófilo Otoni-MG. The research was divided in two phases (First: July and August, 2013 and the second: January and February, 2014), using eleven stallions at the first one and eight at the second one, age between 5 and 25 years old. To determine the serum testosterone, they were blood sampled about 20 days after the beginning of winter(1st phase) and 20 days after the beginning of summer(2nd phase). The samples were collected for 12 hours/day, from 7am to 7pm, each 30 minutes. The testicular biometry was measured at the same Day of the blood sample. To determine the seminal parameters, sêmen was collected from the stallions the two days following the blood samples. At this time, during the semen collects, the reproductive behaviour was evaluated. Regarding the measurements of the testis, the quantitative variables, height, width, lengh and volume of right and left testis did not differ significantly between seasons(P>0.05). The same was observed about seminal and behavioral parameters, volume, appearance, motility, vigor, concentration, membrane integrity, reaction time, latency time, copulation time and number of mounts, in which the results do not indicate differences between seasons(P>0.05). Dispite the fact that the profile of testosterone release are differents during the seasons, there was no difference in means of concentrations (P>0,05). This differences were bigger during the morning, when the concentrations in this time were higher during breeding season. However, there was difference between animal interaction and season,which suggests that in some animals the mean androgen concentrations displayed a seasonal pattern, while in other animals, this behavior was not observed. It was concluded that seasonality has no effect on the reproductive characteristics as testis size, sexual behavior and semen parameters, beyond the average testosterone secretion, so that the influence on the latter not presented correlations with other important traits studied.