Interação genótipo-ambiente e análise da variabilidade no melhoramento genético de linhagens de avós de frangos de corte / Genotype -environment interaction and the analysis of variability in genetic improvement of broilers’ parentals lines of breeding.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2006

RESUMO

The genetic improvement of aviary lines of breeding has contributed to the increasing efficiency of Brazilian poultry. Nevertheless, for the selection of superior genotypes in improvement programs, we must evaluate the existent variability, associated to the creation of birds in different environments. In this sense, with this research, we aimed at evaluating the performance and variability existent among broilers’ parentals lines of breeding, created in different environments, considering genotype-environment interaction. Broilers’ parentals commercial lines of breeding were created till they achieved the age of 42 days-old, in totally controlled environment of pedigree farms, both in common conditions for the creation of broilers and in stressed situations, in order to evaluate zootechnic and morphometric parameters and to study the existent variability among the lines of breeding through multivariate analysis, as well as for the selection of representative variables of this variability. We used thermal welfare status (Temperature and humidity index and Enthalpy) for the evaluation of installations’ internal microclimate to which the birds are exposed. We carried out average comparisons of zootechnic (body weight and carcass yield) and morphometric (feathering) parameters of the lines of breeding created in pedigree, broilers and stressed environments. We developed multivariate analysis in order to form lines of breeding grouping created at broilers and stressed environments. Next, we went through a selection of representative variables of existent variability. Lines of breeding presented different outcomes on the evaluated parameters, due to the creation environment used. Male lines of breeding presented greater body weight and yield of eviscerated carcass and breast; female lines of breeding achieved a greater legs yield and demonstrated greater legs and back featherings. Multivariate analysis allowed the study of variability among lines of breeding and the identification of the most promising crossbreedings in order to obtain superior genotypes. Creation environments influenced representative variable selection and types of existent variability among lines of breeding. The back feathering at 28 days of age may be indicated in morphometric characteristics evaluation on the selection process of the studied lines of breeding.

ASSUNTO(S)

melhoramento genético animal empenamento carcaça (rendimento) frangos de corte selection body weight análise multivariada carcass yield feathering multivariate

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