Criopreservação de sêmen e avaliação histológica e funcional do testículo de periquitos australianos (Melopsittacus undulatus SHAW, 1805)

• Autor(a) principal: Peixoto, Juliano Vogas
• Data de Publicação: 2010
• Tipo de documento: Tese
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/1437
• topic: Criopreservação; Sêmen; Glicerol; Cryopreservation; Semen; Glycerol; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::REPRODUCAO ANIMAL

The budgerigar (Melopsittacus undulatus) in a wild life lives in dry regions and semi-dry in the middle of Australia. Its captive breeding has started in the middle of the XIX century caused by its great ability of adaptation and reproduction. Its considered by the IUCN (2009) as "Least Concern", which means no instinction menace. As well as the major of exotic birds, there is just a few studies of the reproductive morphophysiology of psittaciformes, which comes with the scarcity knowledge of these birds reproduction. The development of assisted reproduction protocols in model species which are not in extinction routes is essential to methodologically expand the use of biothecnics of reproduction. The animals of the present experiment were located inside the Veterinary Hospital of The Federal University of Viçosa. The sperm collection had been done three times a week by digital messages in the celomatic cavity of the backflow. The sperm was collected from the vas deferens of the papillae, the wall of the cloaca, by the graduated micro tubes hematocrit not heparinized. The sperm volume collected were diluted in a Ringer with lactate solution, and the sperm were classified by their motility and sperm vigor, the sperm concentration was calculated too and the percentage of anomalies. Later samples were rediluted inside Lake®, TRIS-citrate-egg yolk and TES-TRIS to the cooling test at 5°C. In the freezing test, the samples were fractionated in 2 rates with 6 and 11% of glycerol. A sample of every treatment was subjected to two freezing processes: one fast curve of cooling/freezing and a real fast curve of cooling/freezing. After thawed the same parameter analysis of the fresh sperm were considered, above the thermoresistence test and the hypoosmotic test, supravital and coloring by fluorescence to check the membrane integrity. The Lake® portion showed better results to the cooling sperm after 24 hours. It was not observed any satisfactory motility result, sperm vigor and membrane integrity tests after the thawed samples at the different protocols. It was also evaluated the spermatogenesis process of budgerigar. Four days before the collection of the testicles, it was introduced 0,1ml of bromodeoxyuridine in the systemic route. The testicles were collected and processed by the routine technique to include resin and paraffin. Resin cuts were colored with blue toluidine and analyzed with qualitative and quantitative technique while the paraffin cuts were colored by the immunocytochemistry technique. It was noticed many indicative rates of high esperm production, as gonadosomatic rate (1,4%) volumetric proportion in the seminiferous tubules (97%), medium diameter of the seminiferous tubules (314 μm), seminiferous epithelium height(96,7 μm), 12,4 meters of seminiferous tubules per gram of testicles, spermatic reservation per gram of testicles (551,7 x 106), spermatic daily production (171,3 x 106) and spermatic daily production per gram of testicle (342,7 x 106). The cell arrangement during the long cycle of the seminiferous epithelium was similar to the one described in mammals, being possible to define 8 stages of the seminiferous epithelium cycle. Similar to the other birds species already studied, five to nine areas with distincted stages were observed in only one cross section of the seminiferous tubule giving the spermatogenesis helical characteristic. The relative frequency of the eight stages of the seminiferous epithelium cycle in budgerigar was: stage 1 (9,35); stage 2 (5,33); stage 3 (26,09); stage 4 (11,06); stage 5 (22,28); stage 6 (16,17); stage 7 (5,89) e stage 8 (3,84). The predivisional stages totaled 40,8%, the divisional 11% and the posdivisional stages totaled 48,2% folowing the same tendency found in quails. The duration of the seminiferous epithelium cycle in budgerigar was about 1,66 days, less than all studied mammals and birds. In the corresponding area of the stage 1 of the budgerigar s seminiferous epithelium cycle, it was observed in average 55,42 spermatogonias, 53,01 young spermatocytes, 44,68 old spermatocytes, 176,56 rounded spermatid and 7,06 Sertoli cells. It was observed loss of approximately 16% of spermatocytes during the meiotic prophase. The registered loss of rounded spermatides during the meiotic division was not significant and that the four expected cells, around 3.95 spermatides were produced. Every Sertoli cell inside the budgerigar s seminiferous epithelium was able to support and to keep 46,72 germline cell, in which 25,02 were rounded spermatides.