Caracterização de três linhagens de codornas de postura alimentadas com rações de alto e baixo nível de energia matabolizável

• Ano de defesa: 2007
• Autor(a) principal: Georg, Priscilla Cristina
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Estadual de Maringá; Brasil; Programa de Pós-Graduação em Zootecnia; UEM; Maringá, PR; Centro de Ciências Agrárias
• Palavras-chave em Português: Codorna de postura; Correlação genética; Herdabilidade; Peso de ovo; Produção de ovos; Peso corporal; Melhoramento genético; Brasil.; Quail posture; Genetic correlation; Heritability; Egg weight; Egg production; Body weight; Breeding; Brazil.; Ciências Agrárias; Zootecnia
• Link de acesso: http://repositorio.uem.br:8080/jspui/handle/1/1687

The experiment was carried out in the Experimental Farm of the Maringá State University, situated in the Iguatemi city, in the laying quail section. There were used three lines of laying quail, fed with high and low metabolizable energy levels, to verify if the birds keeps their genetic propriety in such environments, and also characterize them on the genetic parameters studied. The production traits (egg weight, body weight, feed intake, feed: egg dozen ratio, carcass weight, carcass yield, abdominal fat, egg production) were analyzed by least squares method using the SAEG program. The reduction in the energy level in laying quail ration did not affect, in a general way, the body weight, egg weight, carcass yield and abdominal fat, however, it had effect on feed intake, feed: egg dozen ratio and egg production. The results show the existence of genotype-environment interaction just for egg production in laying quail, at lines level. The analysis of genotype-environment interaction and genetic parameters estimation were realized by MTGSAM software, which allows Bayesian inference, using the Gibbs Sampling, applied to an animal model. Through the heritability and genetic correlations results, it was concluded that there was presence of genotype-environment interaction only for albumen height and shell thickness. The characteristics of egg weight and body weight are susceptible to genetic gains independent of the diet energy level. The body weights show variability, with a greater potential for response to the selection in the line 3. The egg weight had a moderate heritability, with results that varied according to the trait, together examined. In the three lines, the egg production has low potential for obtaining genetic gains if the selection is based on partial records, indicating that to improve this trait, the selection criterion should consider the eggs production in the complete posture cycle. The genetic correlations between egg weights and body weights indicate that the selection to increase egg weight implies in the body weight increase in the three lines, and less intense in line 2 which could lead to increase in production costs. Despite the genetic correlations between the egg production and egg weights come with relatively high and positive magnitude, correlated responses should not be expected since there is lack of genetic variability in the egg production in the first 90 days of laying. The same response should be expected of genetic correlations between egg production and body weights.