Criopreservação de Espermatozoides Suínos da Raça Piau: Avaliação de Curvas de Congelamento e Centrifugações

• Autor(a) principal: Shiomi, Hugo Hideki
• Data de Publicação: 2013
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/5145
• topic: Piau; Criopreservação de sêmen; Suíno; Piau; Cryopreservation of semen; Swine; CNPQ::CIENCIAS AGRARIAS::MEDICINA VETERINARIA::REPRODUCAO ANIMAL

The maintenance of naturalized swine breeds is very important for the Brazilianpork production industry, due to the potential source of new genetic variants. The Piau breed is considered one of the best and the most important Brazilian domestic naturalized swine breeds. Thus, research towards developing protocols for freezing semen is essential in order to create germplasm banks and protect the endangered swine breeds. Protocols for boar semen cryopreservation require the centrifugation of semen in order to separate sperm cells from the seminal plasma, nevertheless it has not been main focus on many studies. The aim on this study was to evaluate the effect of centrifugation and freezing curve in cryopreservation protocol on after thawing sperm viability of Piau swine breed (Sus scrofa), through assessment in vitro tests. Six ejaculates from five Piau boars were used, with ages ranging from 1.5 to 5.0 years, approved by andrologic examination, 30 samples in total. The semen collections were performed using the method of stimulation with a gloved hand with the aid of a dummy or a sow in natural estrus. Two centrifugations (800 G for ten minutes and 2400 G for three minutes) and two freezing curves (with conventional nitrogen vapor- freezing 1 and controlled by a programmed freezing machine- freezing 2) were tested. So the treatments were divided into M3- centrifugation at 2400 G for 3 minutes and freezing 2; M10- centrifugation at 800 G for 10 minutes and freezing 2; R3-centrifugation at 2400 G for 3 minutes and freezing 1; R10- centrifugation 800 for 10 minutes and freezing 1. After thawing, the averages recorded for total sperm motility and vigor of semen were 44.0 ± 10.3 and 3.1 ± 0.4; 44.3 ± 7.7 and 3.0 ± 0.3; 39.2 ± 10.2 and 2.9 ± 0.4; 38.0 ± 9.2 and 2.9 ± 0.4 respectively for treatments M3, M10, R3 and R10, with no difference between the groups (p> 0.05). The mean values in the different treatments did not differ regarding supravital test (39.9 ± 7.9; 40.1 ± 8.1; 37.3 ± 7.0; 36.5 ± 6.8, respectively to M3, M10, R3 and R10), hypoosmotic, the number of sperm bound perivitelline membrane of chicken egg yolk and morphology (p> 0.05). No interaction between freezing curve and centrifugation force was detected, hence the further individual analysis. In the present study it was observed that both the curve and the freezing spin regime influence on after thawing sperm quality, and shorter centrifugation periods and freezing rates decrease with temperature controlled by machine are the most suitable to decrease sperm injuries.