Efeito da incorporação de colesterol à membrana plasmática de espermatozóides sobre o congelamento e fertilidade do sêmen de jumentos (Equus asinus) da raça Pêga

• Ano de defesa: 2011
• Autor(a) principal: Rates, Daniel Macêdo
• Orientador(a): Carvalho, Giovanni Ribeiro de
• Banca de defesa: Costa, Eduardo Paulino da , Paula, Tarcízio Antônio Rego de
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Viçosa
• Programa de Pós-Graduação: Mestrado em Zootecnia
• Departamento: Genética e Melhoramento de Animais Domésticos; Nutrição e Alimentação Animal; Pastagens e Forragicul
• País: BR
• Palavras-chave em Português: Jumento; Criopreservação; Ciclodextrina
• Palavras-chave em Inglês: Donkey; Cryopreservation; Cyclodextrin
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::PRODUCAO ANIMAL
• Link de acesso: http://locus.ufv.br/handle/123456789/5698

The objective of the present study was to evaluate the effectiveness of the cholesterol incorporation, using two different extenders for semen cryopreservation of Pêga donkeys. The effectiveness was determined by in vitro and in vivo tests for assessment of fertility. Twelve ejaculates from two donkeys in Experiment 1 and eight ejaculates from one donkey in Experiment 2 were collected. The semen of each ejaculate was diluted in Stalp extender and in Martin centrifugation extender, respectively, in Experiments 1 and 2 to obtain a final concentration of 120 x 106 sperm/mL and subsequently split into two treatments: T1 - adding 1 mg of cholesterol-loaded cyclodextrin (CLC) to each one mL of semen and T2 - without addition of CLC. The semen in two experiments was cooled and frozen following the methodology described by FÜRST et al. (2005), using the Martin freezing extender. The sperm quality was evaluated in fresh, cooled and thawed semen. The characteristics evaluated were: total motility, sperm vigor, sperm morphology, plasma membrane integrity by supravital test, plasma membrane functionality by hypoosmotic test (HOST) and total motility and sperm vigor during the thermo-resistance test (TTR) for 120 minutes. In each experiment, thirty mares were inseminated with semen from T1 and thirty with semen of T2. The artificial inseminations were done depositing a dose of 300 x 106 motile sperm at the apex of the horn ipsilateral to ovulation. In Experiment 1, the addition of 1 mg of CLC resulted in greater (p<0.05) total sperm motility and better preservation of the sperm membrane functionality. In Experiment 2 there was no difference (p>0.05) between treatments in the semen characteristics evaluated. The thawed semen of T1 and T2 had no difference (p>0.05) between the experiments in the sperm vigor, plasma membrane integrity and total morphological defects. There was no difference (p>0.05) between treatments during the TTR in any experiment. The pregnancy rates in Experiment 1(T1 - 3.3% and T2 &#8211; 10.0 %) and in Experiment 2 (T1 &#8211; 20.0% and T2 &#8211; 13.3%) did not differ (p>0.05) between treatments. The use of Stalp and Martin extenders for incubation and centrifugation of donkey semen has not resulted in satisfactory pregnancy rates in mares inseminated after ovulation. Further studies are needed to improve the fertility of donkey semen frozen with incorporation of CLC.