Estudo genético da produção de ovos em codornas de corte por meio de análises multicaracterísticas e regressão aleatória

• Ano de defesa: 2011
• Autor(a) principal: Teixeira, Bruno Bastos
• Orientador(a): Euclydes, Ricardo Frederico
• Banca de defesa: Carneiro, Antônio Policarpo Souza
• 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: Cutunix cutunix; Eficiência relativa; Ganho genético
• Palavras-chave em Inglês: Cutunix cutunix; Relative efficiency; Genetic gain
• Área do conhecimento CNPq: CNPQ::CIENCIAS AGRARIAS::ZOOTECNIA::GENETICA E MELHORAMENTO DOS ANIMAIS DOMESTICOS
• Link de acesso: http://locus.ufv.br/handle/123456789/5697

The objective of this work, to estimate genetic parameters for the partial periods and the total period of egg production through multi-trait analysis, to verify the possibility of using partial periods of production, replacing total period as selection criteria (Chapter 1) and compare random regression models with different orders in Legendre polynomials, to evaluate the best fit to promote the production of eggs and thus obtain the heritability, variances and correlations. (Chapter 2). Were used in this study data from 1.632 quails, with 816 females and 816 females UFV1 UFV2 belonging to the Program for Breeding Birds of the Federal University of Viçosa. For analysis multicaracterísticas were formed four partial periods of the 6th to the 24th (P24), the 6 th to 32 th (P32), the 6th to the 40th (P40) and the 6th to the 48th (P48) weeks of age and the period of total output (P52) from 6th to 52nd week. We used animal model for analyzing the multi-characteristic by the Wombat application. For the genetic group UFV1, the heritabilities for egg production were 0,072 for the period of total production and production periods for part P24; P32; P40 and P48, these estimates were, respectively, 0,092, 0,096, 0,094 and 0,085. Estimates of genetic correlations were found higher for: P40 x 52 (0,996) and P48 x 52 (0,999). As for the other partial periods P24 x 52 and P32 x 52 genetic correlation values were 0,798 and 0,892. For the genetic group UFV2, the heritabilities for P24, P32, P40, P48 and P52, were respectively 0,090; 0,093; 0,100; 0,116 and 0,131. Genetic correlations showed the highest median values ranging from 0,709 to 0,993. It is recommended for the genetic group UFV1, considering the selection of quail egg production up to 40 weeks of age, as for the genetic group UFV2, the selection until the 48th week of life. The random regression for genetic analysis of egg production was performed using the software Wombat, in the animal model. The proposed model included the fixed effects of generation, the average production history (regression fixed), and random effectsadditive, direct permanent environmental, and waste (e). To model the fixed path, we used the Legendre polynomials of order three (quadratic) and four (cubic). The random trajectories were modeled using Legendre orthogonal polynomials, varying the order of adjustments and three (quadratic) and four (cubic). To test the difference between the models were made comparisons using the Akaike information criterion (AIC) and Bayesian information criterion of Schwarz (BIC), the values of logarithm of the likelihood function (LogeL) and the likelihood ratio test (LRT). For the genetic group UFV1, the model with four Ka = 4 for the additive direct genetic effects and Kc = 4 for the permanent environmental effect of animal, provided better fit and regression coefficient (2*) explained the greatest proportion of variance both for the direct additive genetic effect, and for the permanent environmental effect. Estimates of additive genetic variance ranged from 0,05 to 0,34, permanent environment between 0,53 and 4,29 and between 3,63 to 7,38 phenotypic, with some changes over time. Since the heritabilities found were low. For the genetic group UFV2, the model with four to K= 3, Ka = 4 and Kc = 4, provided better fit and regression coefficient (2*) explained the greatest proportion of variance for both the direct additive genetic effect, and for permanent environment. Estimates of additive genetic variance ranged from 0,12 to 1,75, permanent environment between 0,66 to 4,04 and from 4,04 to 8,67 phenotypic, with some changes over time. Since the heritabilities were low to moderate. For the genetic group UFV1, the model with a Legendre polynomial of order three for the fixed effects and order four for the random effects, can be used to describe the trajectory of egg production and the highest values of heritability are found near to peak production. As for the genetic group UFV2, the model with a Legendre polynomial of order three for the fixed and random trajectories can be used to describe the egg production and the highest values of heritability are found near the end of lay.