Orientador: Frederico Ozanam Papa / Resumo: O presente estudo objetivou a colheita do sêmen de garanhões nos haras, diluição e transporte destas amostras em dois sistemas de refrigeração (Equitainerâ e Max-Semen Expressâ) para os centros especializados onde foram submetidos ao processo de congelação. No Experimento I foi utilizado 01 ejaculado de 12 garanhões de diferentes raças. Após a colheita os ejaculados foram divididos em duas alíquotas: uma submetida ao processo de congelação convencional, utilizando o meio diluidor Botu-Crioâ e outra diluída com Botu-Semenâ e armazenada em Equitainerâ durante 24h. Após a refrigeração o sêmen foi centrifugado e ressuspendido com Botu-Crioâ e submetidas ao processo de congelação. As amostras descongeladas foram analisadas pelo CASA e a integridade de membrana plasmática pelo uso de sondas fluorescentes. Os resultados do Experimento I mostraram que não houve diferença nos parâmetros avaliados (motilidade total, progressiva e integridade da membrana plasmática) entre a metodologia convencional e a congelação de sêmen após 24h de refrigeração (p>0,05). No Experimento II, foi utilizado 01 ejaculado de 11 garanhões, os quais foram diluídos e armazenados em dois sistemas de transporte (Equitainerâ e Max-Semen Expressâ) durante 24h. As amostras foram congeladas, conforme descrito no Experimento I utilizando-se a associação do glicerol com dimetilacetamida, dimetilformamida e metilformamida. Após a descongelação a análise dos parâmetros espermáticos demonstrou a superioridade do Equitainerâ em relação ao Max-Semen Expressâ (p<0,05). A metilformamida associada ao glicerol apresentou resultados superiores aos demais crioprotetores utilizados . O teste de fertilidade comparou amostras congeladas de dois garanhões (A e B) pelos métodos: convencional e pós-refrigeração em Equitainer por 24h.... (Resumo complet, clicar acesso eletrônico abaixo) / Abstract: The aim of the present study was to develop a new method to freeze equine semen. Semen was collected at the stallion farm, diluted, divided into two samples and cooled at Equitainer® or Max-Semen Express®, then transported to an equipped laboratory for freezing. On Experiment I used one ejaculate from each of 11 stallions from different breeds. The ejaculates were divided into two parts: one was frozen following a regular protocol and the other was diluted with Botu-Semen® and stored at Equitainer® for 24 hours. Afterwards, cooled semen was centrifuged and ressuspended with Botu-Crio® and then frozen. After thawing motility was evaluated by CASA and by fluorescent probes for plasma membrane integrity evaluation. Based on these results of Experiment I concluded that there was no difference between total motility, progressive motility and plasma membrane integrity when comparing the two methods for freezing semen (p>0,05). At Experiment II one ejaculate from each of 11 stallions was collected, diluted and stored either an Equitainer® or in a Max-Semen Express® for 24 hours. The samples were frozen as described on Experiment I using the association of glycerol with dimethylformamide, dimethylacetamide and methylformamide. After thawing the results suggested that the Equitainer® was better than Max-Semen Express® in maintaining sperm viability (p>0,05). The association of metilformamida and glycerol was superior to the others. Fertility trials compared the two methods: conventional and cooled/frozen semen. Ten mares were inseminated in a total of 40 cycles; the mares were monitorated every day by ovarian ultrasonography. Ovulation was induced using 10mg EPE (equine pituitary extract) intravenously when a follicle of 35mm of diameter was detected. Inseminations were performed twice, before and after ovulation with 350x106 spermatozoa/mL toward the tip of the horn.... (Complete abstract, access undermentioned electronic address) / Mestre