USO DE DILUENTES E TEMPERATURAS ALTERNATIVAS NA CONSERVAÇÃO PROLONGADA DO SÊMEN DO VARRÃO

The use of appropriate extenders is important for the success of an artificial insemination program. The objective of this study was to evaluate the efficiency of alternative extenders for swine semen at different temperatures (17 to 10 °C). The following extenders were used: Beltsville Thawing Solution (BTS), powdered coconut water (ACP-103®), and skimmed milk powder (LPD). The 50 ejaculates were analyzed daily, in natura and after dilution, during the 5-day period of semen preservation (D0 to D4), regarding spermatic vigor and motility. Acrosome integrity and sperm viability were evaluated on D0 and D4. Data were analyzed using Mann-Whitney, Students, Tukey and chi-square tests (p<0.05). The LPD extender at 10 °C presented higher motility and sperm vigor compared to BTS and ACP until D2, and to treatments stored at 17 °C. Acrosome vitality and integrity remained higher (p<0.001) with LPD at 10 °C on D0 and D4. LPD showed to be a good extender for the swine semen at lower temperature (10 °C). Furthermore, it provided better protection to sperm cells, by allowing greater integrity and vitality of the acrosome

In vitro evaluation of canine spermatozoa cryopreserved in different extenders Avaliação in vitro do sêmen canino criopreservado em diferentes diluidores de congelação

The efficacy of three extenders, tris-egg yolk-5% ethylene glycol (T1), lactose-egg yolk-5% ethylene glycol (T2) and lactose-egg yolk-5% dimethyl formamide (T3) on preserving the viability of post-thawing canine spermatozoa was evaluated. Three ejaculates per dog were obtained of five animals. The semen was packaged in 0.5ml straws and cooled to 4&deg;C for 120min. The straws were frozen 4cm above the nitrogen level for 15min and thawed in water-bath at 37&deg;C for 60sec and at 75&deg;C for 7sec. Progressive motility and vigour were evaluated immediately after thawing (time 0) and at 30, 60, 90 and 120min. Structural and functional integrity of plasma membrane of the spermatozoa were evaluated, respectively, by fluorescent staining probes and hypoosmotic swelling test. Lactose-egg yolk based extenders showed better cryoprotectant capability and dimethyl formamide was an alternative cryoprotectant agent for dog sperm cells.<br>Avaliou-se a eficácia de três diluidores, tris-gema com 5% de etileno glycol (T1), lactose-gema com 5% de etileno glicol (T2) e lactose-gema com 5% de dimetil-formamida (T3) na criopreservação do sêmen de cães. Foram obtidos três ejaculados por cão de um total de cinco animais. O sêmen foi envasado em palhetas de 0,5ml e resfriado até 4&deg;C por 120min. As palhetas foram congeladas 4cm acima do nitrogênio líquido por 15min e descongeladas em banho-maria a 37&deg;C por 60seg e 75&deg;C por 7seg. A motilidade progressiva e o vigor foram avaliados imediatamente após a descongelação (tempo 0) e aos 30, 60, 90 e 120min. A integridade estrutural e funcional da membrana plasmática do espermatozóide foi avaliada, respectivamente, por meio da coloração de fluorescência e pelo teste hiposmótico. Os diluidores à base de lactose gema foram mais eficazes em preservar a viabilidade espermática pós-descongelação e a dimetil-formamida é um crioprotetor eficaz para espermatozóides de cães