Comparação entre os sistemas automatizado e convencional de criopreservação de sêmen bovino

Comparison between the conventional and automated systems of semen bovine cryopreservation

Resumos

O objetivo deste estudo foi comparar a eficiência do sistema automatizado (curva de resfriamento controlada eletronicamente) de congelação de sêmen bovino versus o sistema convencional (curva não controlada) por meio dos parâmetros de qualidade e viabilidade espermática no período pós-descongelação. O sêmen de quatro touros azebuados adultos foram criopreservados simultaneamente em meio tris, gema e glicerol 7%. A avaliação computadorizada do sêmen descongelado detectou os seguintes parâmetros: MP 56,50±22,25%; VAP 34,77±4,25µm/s; VSL 28,17±4,25 µm/s; VCL 58,45±6,85µm/s; STR 82,00±2,31%; LIN 49,50±3,32%, para o sistema automatizado e MP. 57,00±13,11%; VAP 25,75±1,66µm/s; VSL 23,32±1,99µm/s; VCL 63,32±1,79µm/s; STR 82,25±3,59µm/s; LIN 50,00±4,97µm/s para o sistema convencional. Os valores médios das avaliações de integridade de membrana plasmática e integridade acrossomal foram de 54,72±12,55% e 36,13±22,20% para o sistema automatizado e 53,22±13,22% e 47,26±5,74% para o sistema convencional, respectivamente. Com os parâmetros avaliados foi possível identificar que não houve diferença estatística entre os sistemas de criopreservação. Desta forma, a escolha do método de criopreservação do sêmen bovino para utilização direta na propriedade fica a critério do técnico responsável, que deverá se basear na realidade de cada propriedade. Para tanto, sempre se deve considerar que o sistema convencional pode trazer mais variações que o sistema automatizado que, apesar do custo do equipamento, pode garantir repetibilidade nos resultados e consequente qualidade do sêmen bovino criopreservado.

biotecnologia; criopreservação; curvas de congelação; inseminação artificial

The objective of this study was to compare the efficiency of bovine semen cryopreservation using the controlled-rate freezing machine versus the conventional method (uncontrolled curve) by the parameters of sperm quality and viability in post-thaw period. Semen from four adult crossbreed bulls was cryopreserved in Tris-yolk-glycerol medium. The computer assisted analysis of thawed semen detected the following results: PM 56.50±22.25%; VAP 34.77±4.25µm/s; VSL 28.17±4.25µm/s; VCL 58.45±6.85µm/s; STR 82.00±2.31%; LIN 49.50±3.32%, to automated system and PM 57.00±13.11%; VAP 25.75±1.66µm/s; VSL 23.32±1.99µm/s; VCL 63.32±1.79µm/s; STR 82.25±3.59µm/s; LIN 50.00±4.97µm/s to conventional cryopreservation system. The results of plasma membrane and acrosome integrity evaluation were 54.7±12.55% and 36.13±22.20% for the automated system and 53.22±13.22% and 47.26±5.74% for the conventional system, respectively. The parameters evaluated demonstrated that there was no statistical difference between the cryopreservation systems. Thus, the choice of the bovine semen cryopreservation method to be used on a farm is a responsibility of the technician, and should be based on the reality of each farm. Therefore, it is always necessary to consider that the conventional system of bovine semen cryopreservation can vary more than the automated system, which, despite the cost of the equipment, can ensure repeatability of the results and consequent quality of cryopreserved bovine semen.

artificial insemination; biotechnology; bovine sperm; cryopreservation; cryopreservation curve

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Datas de Publicação

• Publicação nesta coleção
  14 Abr 2014
• Data do Fascículo
  Mar 2014

Histórico

• Recebido
  22 Out 2010
• Aceito
  29 Out 2013