Avaliação genética e de efeitos ambientais em características reprodutivas de tilápia do Nilo

• Ano de defesa: 2014
• Autor(a) principal: Yoshida, Grazyella Massako
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Departamento de Zootecnia; Programa de Pós-Graduação em Zootecnia; UEM; Maringá, PR; Centro de Ciências Agrárias
• Palavras-chave em Português: Tilápia do Nilo; Efeito da idade; Variedade genética; Desovas; Efeito do ambiente; Herdabilidade; Brasil.; Nile tilapia; Effect of age; Genetic variety; Spawns; Environmental effect; Heritability; Brazil.; Ciências Agrárias; Zootecnia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/1671

The aim of this work was to investigate the effect of three different age classes and different reproductive environments in Nile tilapia female performance, as well as, to estimate the genetic parameters for reproductive traits using the Bayesian inference methodology. The data set contained information from 451 female Nile tilapia evaluated in two different environments in Maringá, Paraná State and in an environment in Alfenas, Minas Gerais State. The spawning observation was carried once a week from October 2012 to March 2013, corresponding to 23 weeks of evaluation. For statistical analysis it was used the procedure Proc Genmod for the SAS statistical program and for the estimation of genetic parameters the computer program MTGSAM Threshold. The traits studied were spawning success, number of spawning, spawning frequency and volume of eggs/female. In statistical analyzes, Local 2 was inferior to the other Locals for the most of traits when using female of age 2. Statistical differences were not observed between Age 1 and 2 for the same Local of evaluation. The Age 3 present at Local 3 showed superior results when compared with female of age 2 for all traits. The heritability estimates were 0.14, 0.16, 0.53 and 0.02 for spawning success, multiple spawning, spawning frequencies and volume of eggs respectively and repeatability obtained for egg volume was 0.28. The results indicate that older females have higher reproductive performance than female of age 1 and 2 and should avoid the use of animals in individual hapas. Heritability estimates show genetic gain if used reproductive traits as selection criteria.