Utilização do choque osmótico na avaliação da viabilidade de sêmen criopreservado de ovinos

This study evaluated the use of hipoosmotic swelling test (HOST) with deionized water (0 mOsmol), as a method of post thaw ram semen evaluation and correlate their findings with different techniques of semen evaluation. Therefore, twenty semen samples of 20 different adult rams were assessed as for kinetic sperm parameters through computerized system (IVOS 12, Hamiton Thorn Biosciences, Beverly, MA, EUA) and subjective analysis. The sperm membranes viability was carried out by the association of fluorescent probes (propidium iodide, JC-1 and FITC-PSA). The structural integrity of the plasma membrane was also studied through supravital test with eosin and the functional integrity of membrane evaluated by doing the hipoosmotic swelling test with deionized water (0 mOsmol), in the following proportions: One part of semen for 10 (HOST 10), 50 (HOST 50) and 100 (HOST 100) parts of water. After semen dilution in the different proportions it was fixed in formalin-buffered saline and analyzed with regard to percentage of HOST reactive sperm (bent/coiled). The percentage of reaction obtained for HOST 10 (33,1%); HOST 50 (32,8%) and HOST 100 (31,8%) did not differ significantly. HOST 10 presented positive correlation with the plasma membrane integrity by the EOS (r = 0,80; p < 0,05). Positive correlations between HOST 50 and HOST 100 with sperm subpopulation with membrane integrity by fluorescence were observed (r = 0,83 and r = 0,85; p < 0,01). The findings suggest that the HOST with deionized water can provide additional information for post thawing ram sperm viability evaluation.

Criopreservación de semen bovino de la cola del epididimo utilizando los métodos convencional y automatizado

Cryopreservation of sperm is important to preserve the germplasm from animals of genetic value, which can die unexpectedly. This study compares conventional and automated methods of cryopreservation of spermatozoa obtained from the epididymis of bulls post-mortem. Twenty-two epididymides were obtained from a commercial slaughterhouse. Spermatozoa were collected from the tail of the epididymis using the retrograde flow technique. Thus, the samples, which were diluted in 10 ml of extender without glycerol (Botubov® I, Botupharma, Botucatu, SP, Brazil), were evaluated on motility, sperm vigor, structural and functional (swelling hypoosmotic test) membrane integrity, mitochondrial activity, sperm viability and ADN fragmentation. The samples were divided into two aliquots and diluted in extender with glycerol (Botubov® II, Botupharma, Botucatu, SP, Brazil) at a concentration of 50x106 motile sperm/0.5 French straws. One sample was frozen by the conventional method (4 hours at 5°C, in a refrigerator and 20 min in nitrogen vapor) and the other by the automated method (Cryogen® Dualflex, Neovet, Uberaba, MG, Brazil). The parameters were higher in all the tests of fresh sperm samples, with the exception of the swelling hypoosmotic test, which showed no significant difference when the results were compared with sperm frozen by the conventional method. The average motility of fresh spermatozoa was 74%, and conventional and automated averages were 29 and 25%, respectively. Therefore, although cryopreservation techniques reduce sperm quality parameters, the viability of the sperm is maintained, and these methods can be used to preserve sperm.

Termografia digital por infravermelho do escroto e qualidade do sêmen em touros nelore (bos taurus indicus)

Aimed to study the relationship between scrotal temperature on semen quality by use of infrared thermography in Nelore bulls bred extensively. There were scrotal thermography and semen collection. Climatic data were collected by means of globe thermometer. The thermograms of the scrotum were obtained by digital infrared thermography. We carried out ejaculates through electroejaculation for analysis of quantitative and qualitative characteristics. For the data, we used analysis of variance and subsequently applied the Tukey test at 5%. (p <0.05) between animals for sperm vigor, sperm motility between animals and between crops, sperm concentration, total sperm and total viable sperm between groups, between harvests for the scrotum temperatures and climate data. It was concluded that the surface temperatures of the scrotum and climatic factors influence the quality of semen. Thermography is recommended as a complementary test in the evaluation of reproductive bulls.

Trehalose and a calcium chelator for ram semen cryopreservation

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Correlação da circunferência escrotal, citologia testicular e parâmetros do sêmen do epidídimo de touros

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Perfil lipídico da membrana citoplasmática de espermatozoides in natura e criopreservados de jumentos e cavalos

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)